Commit Graph

4827 Commits

Author SHA1 Message Date
Maciej W. Rozycki
4ff4b9e19a ntp: fix calculation of the next jiffie to trigger RTC sync
We have a bug in the calculation of the next jiffie to trigger the RTC
synchronisation.  The aim here is to run sync_cmos_clock() as close as
possible to the middle of a second.  Which means we want this function to
be called less than or equal to half a jiffie away from when now.tv_nsec
equals 5e8 (500000000).

If this is not the case for a given call to the function, for this purpose
instead of updating the RTC we calculate the offset in nanoseconds to the
next point in time where now.tv_nsec will be equal 5e8.  The calculated
offset is then converted to jiffies as these are the unit used by the
timer.

Hovewer timespec_to_jiffies() used here uses a ceil()-type rounding mode,
where the resulting value is rounded up.  As a result the range of
now.tv_nsec when the timer will trigger is from 5e8 to 5e8 + TICK_NSEC
rather than the desired 5e8 - TICK_NSEC / 2 to 5e8 + TICK_NSEC / 2.

As a result if for example sync_cmos_clock() happens to be called at the
time when now.tv_nsec is between 5e8 + TICK_NSEC / 2 and 5e8 to 5e8 +
TICK_NSEC, it will simply be rescheduled HZ jiffies later, falling in the
same range of now.tv_nsec again.  Similarly for cases offsetted by an
integer multiple of TICK_NSEC.

This change addresses the problem by subtracting TICK_NSEC / 2 from the
nanosecond offset to the next point in time where now.tv_nsec will be
equal 5e8, effectively shifting the following rounding in
timespec_to_jiffies() so that it produces a rounded-to-nearest result.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-06 15:31:48 +02:00
Krzysztof Helt
c8bfff6dd4 sched: compilation fix with gcc 3.4.6
I found that 2.6.27-rc5-mm1 does not compile with gcc 3.4.6.
The error is:
  CC      kernel/sched.o
kernel/sched.c: In function `start_rt_bandwidth':
kernel/sched.c:208: sorry, unimplemented: inlining failed in call to 'rt_bandwidth_enabled': function body not available
kernel/sched.c:214: sorry, unimplemented: called from here
make[1]: *** [kernel/sched.o] Error 1
make: *** [kernel] Error 2

It seems that the gcc 3.4.6 requires full inline definition before first usage.
The patch below fixes the compilation problem.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl> (if needed>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-06 15:17:09 +02:00
Thomas Gleixner
7300711e8c clockevents: broadcast fixup possible waiters
Until the C1E patches arrived there where no users of periodic broadcast
before switching to oneshot mode. Now we need to trigger a possible
waiter for a periodic broadcast when switching to oneshot mode.
Otherwise we can starve them for ever.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-09-06 07:21:17 +02:00
Balbir Singh
49048622ea sched: fix process time monotonicity
Spencer reported a problem where utime and stime were going negative despite
the fixes in commit b27f03d4bd. The suspected
reason for the problem is that signal_struct maintains it's own utime and
stime (of exited tasks), these are not updated using the new task_utime()
routine, hence sig->utime can go backwards and cause the same problem
to occur (sig->utime, adds tsk->utime and not task_utime()). This patch
fixes the problem

TODO: using max(task->prev_utime, derived utime) works for now, but a more
generic solution is to implement cputime_max() and use the cputime_gt()
function for comparison.

Reported-by: spencer@bluehost.com
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 18:14:35 +02:00
Peter Zijlstra
56c7426b39 sched_clock: fix NOHZ interaction
If HLT stops the TSC, we'll fail to account idle time, thereby inflating the
actual process times. Fix this by re-calibrating the clock against GTOD when
leaving nohz mode.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 18:14:08 +02:00
Thomas Gleixner
1fb9b7d29d clockevents: prevent endless loop lockup
The C1E/HPET bug reports on AMDX2/RS690 systems where tracked down to a
too small value of the HPET minumum delta for programming an event.

The clockevents code needs to enforce an interrupt event on the clock event
device in some cases. The enforcement code was stupid and naive, as it just
added the minimum delta to the current time and tried to reprogram the device.
When the minimum delta is too small, then this loops forever.

Add a sanity check. Allow reprogramming to fail 3 times, then print a warning
and double the minimum delta value to make sure, that this does not happen again.
Use the same function for both tick-oneshot and tick-broadcast code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 11:11:53 +02:00
Thomas Gleixner
9c17bcda99 clockevents: prevent multiple init/shutdown
While chasing the C1E/HPET bugreports I went through the clock events
code inch by inch and found that the broadcast device can be initialized
and shutdown multiple times. Multiple shutdowns are not critical, but
useless waste of time. Multiple initializations are simply broken. Another
CPU might have the device in use already after the first initialization and
the second init could just render it unusable again.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 11:11:52 +02:00
Thomas Gleixner
7205656ab4 clockevents: enforce reprogram in oneshot setup
In tick_oneshot_setup we program the device to the given next_event,
but we do not check the return value. We need to make sure that the
device is programmed enforced so the interrupt handler engine starts
working. Split out the reprogramming function from tick_program_event()
and call it with the device, which was handed in to tick_setup_oneshot().
Set the force argument, so the devices is firing an interrupt.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 11:11:52 +02:00
Thomas Gleixner
d4496b3955 clockevents: prevent endless loop in periodic broadcast handler
The reprogramming of the periodic broadcast handler was broken,
when the first programming returned -ETIME. The clockevents code
stores the new expiry value in the clock events device next_event field
only when the programming time has not been elapsed yet. The loop in
question calculates the new expiry value from the next_event value
and therefor never increases.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 11:11:51 +02:00
Venkatesh Pallipadi
7c1e768974 clockevents: prevent clockevent event_handler ending up handler_noop
There is a ordering related problem with clockevents code, due to which
clockevents_register_device() called after tickless/highres switch
will not work. The new clockevent ends up with clockevents_handle_noop as
event handler, resulting in no timer activity.

The problematic path seems to be

* old device already has hrtimer_interrupt as the event_handler
* new clockevent device registers with a higher rating
* tick_check_new_device() is called
  * clockevents_exchange_device() gets called
    * old->event_handler is set to clockevents_handle_noop
  * tick_setup_device() is called for the new device
    * which sets new->event_handler using the old->event_handler which is noop.

Change the ordering so that new device inherits the proper handler.

This does not have any issue in normal case as most likely all the clockevent
devices are setup before the highres switch. But, can potentially be affecting
some corner case where HPET force detect happens after the highres switch.
This was a problem with HPET in MSI mode code that we have been experimenting
with.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 11:11:51 +02:00
Ingo Molnar
0c8c708a7e Merge branch 'x86/core' into x86/unify-cpu-detect 2008-09-05 09:27:23 +02:00
Ingo Molnar
8040d77688 Merge branch 'core/resources' into x86/core 2008-09-04 21:04:04 +02:00
Yinghai Lu
268364a0f4 IO resources: add reserve_region_with_split()
add reserve_region_with_split() to not lose e820 reserved entries if
they overlap with existing IO regions:

with test case by extend 0xe0000000 - 0xeffffff to 0xdd800000 -
we get:
	e0000000-efffffff : PCI MMCONFIG 0
		 e0000000-efffffff : reserved

and in /proc/iomem we get:
	found conflict for reserved [dd800000, efffffff], try to reserve with split
	    __reserve_region_with_split: (PCI Bus #80) [dd000000, ddffffff], res: (reserved) [dd800000, efffffff]
	    __reserve_region_with_split: (PCI Bus #00) [de000000, dfffffff], res: (reserved) [de000000, efffffff]
	initcall pci_subsys_init+0x0/0x121 returned 0 after 381 msecs
in dmesg

various fixes and improvements suggested by Linus.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-04 21:02:44 +02:00
Al Viro
b380b0d4f7 forgotten refcount on sysctl root table
We should've set refcount on the root sysctl table; otherwise we'll blow
up the first time we get down to zero dynamically registered sysctl
tables.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-04 11:06:21 -07:00
H. Peter Anvin
0ccd8c39bc Merge branch 'linus' into x86/core 2008-09-04 08:09:09 -07:00
H. Peter Anvin
7203781c98 Merge branch 'x86/cpu' into x86/core
Conflicts:

	arch/x86/kernel/cpu/feature_names.c
	include/asm-x86/cpufeature.h
2008-09-04 08:08:42 -07:00
John Kacur
9d35935747 pm_qos_requirement might sleep
Make PM_QOS and CPU_IDLE play nicer when run with the RT-Preempt kernel.

The purpose of the patch is to remove the spin_lock around the read in the
function pm_qos_requirement - since spinlocks can sleep in -rt and this
function is called from idle.

CPU_IDLE polls the target_value's of some of the pm_qos parameters from
the idle loop causing sleeping locking warnings.  Changing the
target_value to an atomic avoids this issue.

Remove the spinlock in pm_qos_requirement by making target_value an atomic
type.

Signed-off-by: mark gross <mgross@linux.intel.com>
Signed-off-by: John Kacur <jkacur@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02 19:21:40 -07:00
Oleg Nesterov
950bbabb5a pid_ns: (BUG 11391) change ->child_reaper when init->group_leader exits
We don't change pid_ns->child_reaper when the main thread of the
subnamespace init exits.  As Robert Rex <robert.rex@exasol.com> pointed
out this is wrong.

Yes, the re-parenting itself works correctly, but if the reparented task
exits it needs ->parent->nsproxy->pid_ns in do_notify_parent(), and if the
main thread is zombie its ->nsproxy was already cleared by
exit_task_namespaces().

Introduce the new function, find_new_reaper(), which finds the new
->parent for the re-parenting and changes ->child_reaper if needed.  Kill
the now unneeded exit_child_reaper().

Also move the changing of ->child_reaper from zap_pid_ns_processes() to
find_new_reaper(), this consolidates the games with ->child_reaper and
makes it stable under tasklist_lock.

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=11391

Reported-by: Robert Rex <robert.rex@exasol.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02 19:21:38 -07:00
Oleg Nesterov
add0d4dfd6 pid_ns: zap_pid_ns_processes: fix the ->child_reaper changing
zap_pid_ns_processes() sets pid_ns->child_reaper = NULL, this is wrong.

Yes, we have already killed all tasks in this namespace, and sys_wait4()
doesn't see any child.  But this doesn't mean ->children list is empty, we
may have EXIT_DEAD tasks which are not visible to do_wait().  In that case
the subsequent forget_original_parent() will crash the kernel because it
will try to re-parent these tasks to the NULL reaper.

Even if there are no childs, it is not good that forget_original_parent()
uses reaper == NULL.

Change the code to set ->child_reaper = init_pid_ns.child_reaper instead.
We could use pid_ns->parent->child_reaper as well, I think this does not
really matter.  These EXIT_DEAD tasks are not visible to the new ->parent
after re-parenting, they will silently do release_task() eventually.

Note that we must change ->child_reaper, otherwise
forget_original_parent() will use reaper == father, and in that case we
will hit the (correct) BUG_ON(!list_empty(&father->children)).

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02 19:21:38 -07:00
Linus Torvalds
99039e1352 Merge branch 'audit.b57' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current
* 'audit.b57' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
  [PATCH] audit: Moved variable declaration to beginning of function
2008-09-02 11:04:47 -07:00
Oleg Nesterov
cbaed698f3 softlockup: minor cleanup, don't check task->state twice
The recent commit 16d9679f33caf7e683471647d1472bfe133d858 changed
check_hung_task() to filter out the TASK_KILLABLE tasks. We can
move this check to the caller which has to test t->state anyway.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02 10:49:51 -07:00
Randy Dunlap
6781f4ae30 kernel/resource.c: fix new kernel-doc warning
Fix kernel-doc warning for new function:

Warning(linux-2.6.27-rc5-git2//kernel/resource.c:448): No description found for parameter 'root'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02 10:47:30 -07:00
Cordelia
c4bacefb7a [PATCH] audit: Moved variable declaration to beginning of function
got rid of compilation warning:
ISO C90 forbids mixed declarations and code

Signed-off-by: Cordelia Sam <cordesam@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-09-01 23:06:45 -04:00
Linus Torvalds
bef69ea0dc Resource handling: add 'insert_resource_expand_to_fit()' function
Not used anywhere yet, but this complements the existing plain
'insert_resource()' functionality with a version that can expand the
resource we are adding in order to fix up any conflicts it has with
existing resources.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-29 20:25:20 -07:00
Andi Kleen
316d9679f3 Don't trigger softlockup detector on network fs blocked tasks
Pulling the ethernet cable on a 2.6.27-rc system with NFS mounts
currently leads to an ongoing flood of soft lockup detector backtraces
for all tasks blocked on the NFS mounts when the hickup takes
longer than 120s.

I don't think NFS problems should be all that noisy.

Luckily there's a reasonably easy way to distingush this case.

Don't report task softlockup warnings for tasks in TASK_KILLABLE
state, which is used by the network file systems.

I believe this patch is a 2.6.27 candidate.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-29 14:46:29 -07:00
Linus Torvalds
66833d5f39 Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  exit signals: use of uninitialized field notify_count
  lockdep: fix invalid list_del_rcu in zap_class
  lockstat: repair erronous contention statistics
  lockstat: fix numerical output rounding error
2008-08-28 12:31:49 -07:00
Linus Torvalds
0234bf1d98 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: rt-bandwidth accounting fix
  sched: fix sched_rt_rq_enqueue() resched idle
2008-08-28 12:31:12 -07:00
Linus Torvalds
e52c8857e0 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: update defconfigs
  x86: msr: fix bogus return values from rdmsr_safe/wrmsr_safe
  x86: cpuid: correct return value on partial operations
  x86: msr: correct return value on partial operations
  x86: cpuid: propagate error from smp_call_function_single()
  x86: msr: propagate errors from smp_call_function_single()
  smp: have smp_call_function_single() detect invalid CPUs
2008-08-28 12:30:59 -07:00
Rafael J. Wysocki
41108eb101 ftrace: disable tracing for hibernation
In accordance with commit f42ac38c59
("ftrace: disable tracing for suspend to ram"), disable tracing
around the suspend code in hibernation code paths.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-28 12:27:39 -07:00
Peter Zijlstra
cc2991cf15 sched: rt-bandwidth accounting fix
It fixes an accounting bug where we would continue accumulating runtime
even though the bandwidth control is disabled. This would lead to very long
throttle periods once bandwidth control gets turned on again.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-28 13:42:38 +02:00
Ingo Molnar
7940ca3605 sched: extract walk_tg_tree(), fix
fix:

 kernel/sched.c: In function '__rt_schedulable':
 kernel/sched.c:8771: error: implicit declaration of function 'walk_tg_tree'
 kernel/sched.c:8771: error: 'tg_nop' undeclared (first use in this function)
 kernel/sched.c:8771: error: (Each undeclared identifier is reported only once
 kernel/sched.c:8771: error: for each function it appears in.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-28 12:08:00 +02:00
Ingo Molnar
aef745fca0 sched: clean up __might_sleep()
add KERN_ to the printout and clean up the flow a bit.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-28 11:36:03 +02:00
Joe Korty
29cbef4869 make might_sleep() display the oopsing process
Expand might_sleep's printk to indicate the oopsing process.

Signed-off-by: Joe Korty <joe.korty@ccur.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-28 11:36:02 +02:00
Bharata B Rao
aec0a5142c sched: call resched_task() conditionally from new task wake up path
- During wake up of a new task, task_new_fair() can do a resched_task()
  on the current task. Later in the code path, check_preempt_curr() also ends
  up doing the same, which can be avoided. Check if TIF_NEED_RESCHED is
  already set for the current task.

- task_new_fair() does a resched_task() on the current task unconditionally.
  This can be done only in case when child runs before the parent.

So this is a small speedup.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-28 11:35:51 +02:00
John Blackwood
f3ade83780 sched: fix sched_rt_rq_enqueue() resched idle
When sysctl_sched_rt_runtime is set to something other than -1 and the
CONFIG_RT_GROUP_SCHED kernel parameter is NOT enabled, we get into a state
where we see one or more CPUs idling forvever even though there are
real-time
tasks in their rt runqueue that are able to run (no longer throttled).

The sequence is:

- A real-time task is running when the timer sets the rt runqueue
    to throttled, and the rt task is resched_task()ed and switched
    out, and idle is switched in since there are no non-rt tasks to
    run on that cpu.

- Eventually the do_sched_rt_period_timer() runs and un-throttles
    the rt runqueue, but we just exit the timer interrupt and go back
    to executing the idle task in the idle loop forever.

If we change the sched_rt_rq_enqueue() routine to use some of the code
from the CONFIG_RT_GROUP_SCHED enabled version of this same routine and
resched_task() the currently executing task (idle in our case) if it is
a lower priority task than the higher rt task in the now un-throttled
runqueue, the problem is no longer observed.

Signed-off-by: John Blackwood <john.blackwood@ccur.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-28 11:13:24 +02:00
Steven Rostedt
f42ac38c59 ftrace: disable tracing for suspend to ram
I've been painstakingly debugging the issue with suspend to ram and
ftraced. The 2.6.28 code does not have this issue, but since the mcount
recording is not going to be in 27, this must be solved for the ftrace
daemon version.

The resume from suspend to ram would reboot because it was triple
faulting. Debugging further, I found that calling the mcount function
itself was not an issue, but it would fault when it incremented
preempt_count. preempt_count is on the tasks info structure that is on the
low memory address of the task's stack.  For some reason, it could not
write to it. Resuming out of suspend to ram does quite a lot of funny
tricks to get to work, so it is not surprising at all that simply doing a
preempt_disable() would cause a fault.

Thanks to Rafael for suggesting to add a "while (1);" to find the place in
resuming that is causing the fault. I would place the loop somewhere in
the code, compile and reboot and see if it would either reboot (hit the
fault) or simply hang (hit the loop).  Doing this over and over again, I
narrowed it down that it was happening in enable_nonboot_cpus.

At this point, I found that it is easier to simply disable tracing around
the suspend code, instead of searching for the particular function that
can not handle doing a preempt_disable.

This patch disables the tracer as it suspends and reenables it on resume.

I tested this patch on my Laptop, and it can resume fine with the patch.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-27 13:54:20 -07:00
Hiroshi Shimamoto
0cd418ddb1 rcuclassic: fix compiler warning
CC      kernel/rcuclassic.o
kernel/rcuclassic.c: In function 'rcu_init_percpu_data':
kernel/rcuclassic.c:705: warning: comparison of distinct pointer types lacks a cast
kernel/rcuclassic.c:713: warning: comparison of distinct pointer types lacks a cast

flags should be unsigned long.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-27 09:28:07 +02:00
Steve VanDeBogart
2633f0e57b exit signals: use of uninitialized field notify_count
task->signal->notify_count is only initialized if
task->signal->group_exit_task is not NULL.  Reorder a conditional so
that uninitialised memory is not used.  Found by Valgrind.

Signed-off-by: Steve VanDeBogart <vandebo-lkml@nerdbox.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-27 09:10:09 +02:00
Zhu Yi
7487017282 lockdep: fix invalid list_del_rcu in zap_class
The problem is found during iwlagn driver testing on
v2.6.27-rc4-176-gb8e6c91 kernel, but it turns out to be a lockdep bug.
In our testing, we frequently load and unload the iwlagn driver
(>50 times). Then the MAX_STACK_TRACE_ENTRIES is reached (expected
behaviour?). The error message with the call trace is as below.

BUG: MAX_STACK_TRACE_ENTRIES too low!
turning off the locking correctness validator.
Pid: 4895, comm: iwlagn Not tainted 2.6.27-rc4 #13

Call Trace:
 [<ffffffff81014aa1>] save_stack_trace+0x22/0x3e
 [<ffffffff8105390a>] save_trace+0x8b/0x91
 [<ffffffff81054e60>] mark_lock+0x1b0/0x8fa
 [<ffffffff81056f71>] __lock_acquire+0x5b9/0x716
 [<ffffffffa00d818a>] ieee80211_sta_work+0x0/0x6ea [mac80211]
 [<ffffffff81057120>] lock_acquire+0x52/0x6b
 [<ffffffff81045f0e>] run_workqueue+0x97/0x1ed
 [<ffffffff81045f5e>] run_workqueue+0xe7/0x1ed
 [<ffffffff81045f0e>] run_workqueue+0x97/0x1ed
 [<ffffffff81046ae4>] worker_thread+0xd8/0xe3
 [<ffffffff81049503>] autoremove_wake_function+0x0/0x2e
 [<ffffffff81046a0c>] worker_thread+0x0/0xe3
 [<ffffffff810493ec>] kthread+0x47/0x73
 [<ffffffff8128e3ab>] trace_hardirqs_on_thunk+0x3a/0x3f
 [<ffffffff8100cea9>] child_rip+0xa/0x11
 [<ffffffff8100c4df>] restore_args+0x0/0x30
 [<ffffffff810316e1>] finish_task_switch+0x0/0xcc
 [<ffffffff810493a5>] kthread+0x0/0x73
 [<ffffffff8100ce9f>] child_rip+0x0/0x11

Although the above is harmless, when the ilwagn module is removed
later lockdep will trigger a kernel oops as below.

BUG: unable to handle kernel NULL pointer dereference at
0000000000000008
IP: [<ffffffff810531e1>] zap_class+0x24/0x82
PGD 73128067 PUD 7448c067 PMD 0
Oops: 0002 [1] SMP
CPU 0
Modules linked in: rfcomm l2cap bluetooth autofs4 sunrpc
nf_conntrack_ipv6 xt_state nf_conntrack xt_tcpudp ip6t_ipv6header
ip6t_REJECT ip6table_filter ip6_tables x_tables ipv6 cpufreq_ondemand
acpi_cpufreq dm_mirror dm_log dm_multipath dm_mod snd_hda_intel sr_mod
snd_seq_dummy snd_seq_oss snd_seq_midi_event battery snd_seq
snd_seq_device cdrom button snd_pcm_oss snd_mixer_oss snd_pcm
snd_timer snd_page_alloc e1000e snd_hwdep sg iTCO_wdt
iTCO_vendor_support ac pcspkr i2c_i801 i2c_core snd soundcore video
output ata_piix ata_generic libata sd_mod scsi_mod ext3 jbd mbcache
uhci_hcd ohci_hcd ehci_hcd [last unloaded: mac80211]
Pid: 4941, comm: modprobe Not tainted 2.6.27-rc4 #10
RIP: 0010:[<ffffffff810531e1>]  [<ffffffff810531e1>]
zap_class+0x24/0x82
RSP: 0000:ffff88007bcb3eb0  EFLAGS: 00010046
RAX: 0000000000068ee8 RBX: ffffffff8192a0a0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000001dfb RDI: ffffffff816e70b0
RBP: ffffffffa00cd000 R08: ffffffff816818f8 R09: ffff88007c923558
R10: ffffe20002ad2408 R11: ffffffff811028ec R12: ffffffff8192a0a0
R13: 000000000002bd90 R14: 0000000000000000 R15: 0000000000000296
FS:  00007f9d1cee56f0(0000) GS:ffffffff814a58c0(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000008 CR3: 0000000073047000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process modprobe (pid: 4941, threadinfo ffff88007bcb2000, task
ffff8800758d1fc0)
Stack:  ffffffff81057376 0000000000000000 ffffffffa00f7b00
0000000000000000
 0000000000000080 0000000000618278 00007fff24f16720 0000000000000000
 ffffffff8105d37a ffffffffa00f7b00 ffffffff8105d591 313132303863616d
Call Trace:
 [<ffffffff81057376>] ? lockdep_free_key_range+0x61/0xf5
 [<ffffffff8105d37a>] ? free_module+0xd4/0xe4
 [<ffffffff8105d591>] ? sys_delete_module+0x1de/0x1f9
 [<ffffffff8106dbfa>] ? audit_syscall_entry+0x12d/0x160
 [<ffffffff8100be2b>] ? system_call_fastpath+0x16/0x1b

Code: b2 00 01 00 00 00 c3 31 f6 49 c7 c0 10 8a 61 81 eb 32 49 39 38
75 26 48 98 48 6b c0 38 48 8b 90 08 8a 61 81 48 8b 88 00 8a 61 81 <48>
89 51 08 48 89 0a 48 c7 80 08 8a 61 81 00 02 20 00 48 ff c6
RIP  [<ffffffff810531e1>] zap_class+0x24/0x82
 RSP <ffff88007bcb3eb0>
CR2: 0000000000000008
---[ end trace a1297e0c4abb0f2e ]---

The root cause for this oops is in add_lock_to_list() when
save_trace() fails due to MAX_STACK_TRACE_ENTRIES is reached,
entry->class is assigned but entry is never added into any lock list.
This makes the list_del_rcu() in zap_class() oops later when the
module is unloaded. This patch fixes the problem by assigning
entry->class after save_trace() returns success.

Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-27 08:40:36 +02:00
Joe Korty
04148b73b8 lockstat: repair erronous contention statistics
Fix bad contention counting in /proc/lock_stat.

/proc/lockstat tries to gather per-ip contention
statistics per-lock.  This was failing due to
a garbage per-ip index selector being used.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-26 10:37:47 +02:00
Joe Korty
2189459d25 lockstat: fix numerical output rounding error
Fix rounding error in /proc/lock_stat numerical output.

On occasion the two digit fractional part contains the three
digit value '100'.  This is due to a bug in the rounding algorithm
which pushes values in the range '95..99' to '100' rather than
to '00' + an increment to the integer part.  For example,

	- 123456.100      old display
	+ 123457.00	  new display

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-26 10:37:46 +02:00
Kevin Diggs
65eb3dc609 sched: add kernel doc for the completion, fix kernel-doc-nano-HOWTO.txt
This patch adds kernel doc for the completion feature.

An error in the split-man.pl PERL snippet in kernel-doc-nano-HOWTO.txt is
also fixed.

Signed-off-by: Kevin Diggs <kevdig@hypersurf.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-26 10:26:54 +02:00
Ingo Molnar
3cf430b063 Merge branch 'linus' into sched/devel 2008-08-26 10:25:59 +02:00
H. Peter Anvin
f73be6dedf smp: have smp_call_function_single() detect invalid CPUs
Have smp_call_function_single() return invalid CPU indicies and return
-ENXIO.  This function is already executed inside a
get_cpu()..put_cpu() which locks out CPU removal, so rather than
having the higher layers doing another layer of locking to guard
against unplugged CPUs do the test here.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-08-25 17:45:48 -07:00
Linus Torvalds
cc556c5c92 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched_clock: fix cpu_clock()
2008-08-25 11:26:02 -07:00
Linus Torvalds
ffb4ba76a2 [module] Don't let gcc inline load_module()
'load_module()' is a complex function that contains all the ELF section
logic, and inlining it is utterly insane.  But gcc will do it, simply
because there is only one call-site.  As a result, all the stack space
that is allocated for all the work to load the module will still be
active when we actually call the module init sequence, and the deep call
chain makes stack overflows happen.

And stack overflows are really hard to debug, because they not only
corrupt random pages below the stack, but also corrupt the thread_info
structure that is allocated under the stack.

In this case, Alan Brunelle reported some crazy oopses at bootup, after
loading the processor module that ends up doing complex ACPI stuff and
has quite a deep callchain.  This should fix it, and is the sane thing
to do regardless.

Cc: Alan D. Brunelle <Alan.Brunelle@hp.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-25 11:10:26 -07:00
Peter Zijlstra
354879bb97 sched_clock: fix cpu_clock()
This patch fixes 3 issues:

a) it removes the dependency on jiffies, because jiffies are incremented
   by a single CPU, and the tick is not synchronized between CPUs. Therefore
   relying on it to calculate a window to clip whacky TSC values doesn't work
   as it can drift around.

   So instead use [GTOD, GTOD+TICK_NSEC) as the window.

b) __update_sched_clock() did (roughly speaking):

   delta = sched_clock() - scd->tick_raw;
   clock += delta;

   Which gives exponential growth, instead of linear.

c) allows the sched_clock_cpu() value to warp the u64 without breaking.

the results are more reliable sched_clock() deltas:

           before       after   sched_clock

cpu_clock: 15750        51312   51488
cpu_clock: 59719        51052   50947
cpu_clock: 15879        51249   51061
cpu_clock: 1            50933   51198
cpu_clock: 1            50931   51039
cpu_clock: 1            51093   50981
cpu_clock: 1            51043   51040
cpu_clock: 1            50959   50938
cpu_clock: 1            50981   51011
cpu_clock: 1            51364   51212
cpu_clock: 1            51219   51273
cpu_clock: 1            51389   51048
cpu_clock: 1            51285   51611
cpu_clock: 1            50964   51137
cpu_clock: 1            50973   50968
cpu_clock: 1            50967   50972
cpu_clock: 1            58910   58485
cpu_clock: 1            51082   51025
cpu_clock: 1            50957   50958
cpu_clock: 1            50958   50957
cpu_clock: 1006128      51128   50971
cpu_clock: 1            51107   51155
cpu_clock: 1            51371   51081
cpu_clock: 1            51104   51365
cpu_clock: 1            51363   51309
cpu_clock: 1            51107   51160
cpu_clock: 1            51139   51100
cpu_clock: 1            51216   51136
cpu_clock: 1            51207   51215
cpu_clock: 1            51087   51263
cpu_clock: 1            51249   51177
cpu_clock: 1            51519   51412
cpu_clock: 1            51416   51255
cpu_clock: 1            51591   51594
cpu_clock: 1            50966   51374
cpu_clock: 1            50966   50966
cpu_clock: 1            51291   50948
cpu_clock: 1            50973   50867
cpu_clock: 1            50970   50970
cpu_clock: 998306       50970   50971
cpu_clock: 1            50971   50970
cpu_clock: 1            50970   50970
cpu_clock: 1            50971   50971
cpu_clock: 1            50970   50970
cpu_clock: 1            51351   50970
cpu_clock: 1            50970   51352
cpu_clock: 1            50971   50970
cpu_clock: 1            50970   50970
cpu_clock: 1            51321   50971
cpu_clock: 1            50974   51324

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-25 17:39:57 +02:00
Adrian Bunk
7a8fc9b248 removed unused #include <linux/version.h>'s
This patch lets the files using linux/version.h match the files that
#include it.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-23 12:14:12 -07:00
Linus Torvalds
43cc071db8 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: enable LB_BIAS by default
2008-08-22 08:36:55 -07:00
Linus Torvalds
05f57f50e0 Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rcu: fix synchronize_rcu() so that kernel-doc works
2008-08-22 08:36:42 -07:00
Oleg Nesterov
93dcf55f82 wait_task_inactive: "improve" the returned value for ->nvcsw == 0
wait_task_inactive() returns 1 when p->nvcsw == 0 || p->nvcsw == 1.  This
means that two subsequent calls can return the same number while the task
was scheduled in between.

Change the code to return "nvcsw | LONG_MIN" instead of "nvcsw ?: 1", now
the overlap always needs LONG_MAX schedules.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-22 15:17:31 +02:00
Oleg Nesterov
f31e11d87a wait_task_inactive(): don't consider task->nivcsw
If wait_task_inactive() returns success the task was deactivated.  In that
case schedule() always increments ->nvcsw which alone can be used as a
"generation counter".

If the next call returns the same number, we can be sure that the task was
unscheduled.  Otherwise, because we know that .on_rq == 0 again, ->nvcsw
should have been changed in between.

Q: perhaps it is better to do "ncsw = (p->nvcsw << 1) | 1" ?  This
decreases the possibility of "was it unscheduled" false positive when
->nvcsw == 0.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-22 15:17:29 +02:00
Oleg Nesterov
94d3d8247d sched: do_wait_for_common: use signal_pending_state()
Change do_wait_for_common() to use signal_pending_state() instead of open
coding.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-22 15:17:28 +02:00
Ingo Molnar
a38409fbb5 dma-coherent: export dma_[alloc|release]_from_coherent methods
fixes modular builds:

  ERROR: "dma_alloc_from_coherent" [sound/core/snd-page-alloc.ko] undefined!
  ERROR: "dma_release_from_coherent" [sound/core/snd-page-alloc.ko] undefined!

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-22 08:34:53 +02:00
Paul E. McKenney
275a89bdd3 rcu: use irq-safe locks
Some earlier tip/core/rcu patches caused RCU to incorrectly enable irqs
too early in boot.  This caused Yinghai's repeated-kexec testing to
hit oopses, presumably due to so that device interrupts left over from
the prior kernel instance (which would oops the newly booting kernel
before it got a chance to reset said devices).  This patch therefore
converts all the local_irq_disable()s in rcuclassic.c to local_irq_save().

Besides, I never did like local_irq_disable() anyway.  ;-)

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-21 16:01:02 +02:00
Miao Xie
3c4fbe5e01 nohz: fix wrong event handler after online an offlined cpu
On the tickless system(CONFIG_NO_HZ=y and CONFIG_HIGH_RES_TIMERS=n), after
I made an offlined cpu online, I found this cpu's event handler was
tick_handle_periodic, not tick_nohz_handler.

After debuging, I found this bug was caused by the wrong tick mode.  the
tick mode is not changed to NOHZ_MODE_INACTIVE when the cpu is offline.

This patch fixes this bug.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-21 09:54:06 +02:00
Randy Dunlap
01dcb0443e rcu: fix synchronize_rcu() so that kernel-doc works
Fix RCU's synchronize_rcu() so that it looks like a C function, enabling
it to be recognized as a function with kernel-doc annotation.

Warning(linux-2.6.26-git11//kernel/rcupdate.c:81): No description found for parameter 'synchronize_rcu'
Warning(linux-2.6.26-git11//kernel/rcupdate.c:81): No description found for parameter 'call_rcu'

[akpm@linux-foundation.org: fix comment]
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-21 09:31:44 +02:00
Peter Zijlstra
efc2dead2c sched: enable LB_BIAS by default
Yanmin reported a significant regression on his 16-core machine due to:

  commit 93b75217df
  Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
  Date:   Fri Jun 27 13:41:33 2008 +0200

Flip back to the old behaviour.

Reported-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-21 08:18:02 +02:00
Ken Chen
2d70b68d42 fix setpriority(PRIO_PGRP) thread iterator breakage
When user calls sys_setpriority(PRIO_PGRP ...) on a NPTL style multi-LWP
process, only the task leader of the process is affected, all other
sibling LWP threads didn't receive the setting.  The problem was that the
iterator used in sys_setpriority() only iteartes over one task for each
process, ignoring all other sibling thread.

Introduce a new macro do_each_pid_thread / while_each_pid_thread to walk
each thread of a process.  Convert 4 call sites in {set/get}priority and
ioprio_{set/get}.

Signed-off-by: Ken Chen <kenchen@google.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-20 15:40:32 -07:00
Roland McGrath
1b04624f93 tracehook: fix SA_NOCLDWAIT
I outwitted myself again in commit 2b2a1ff64a,
and broke the SA_NOCLDWAIT behavior so it leaks zombies.  This fixes it.

Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Roland McGrath <roland@redhat.com>
2008-08-19 20:37:07 -07:00
Peter Zijlstra
9a7e0b180d sched: rt-bandwidth fixes
The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting
for the group scheduler - however it doesn't deal with sched_setscheduler(),
which will keep tasks out of groups that have no assigned runtime.

If we relax this, we get into the situation where RT tasks can get into a group
when we disable bandwidth control, and then starve them by enabling it again.

Rework the schedulability code to check for this condition and fail to turn
on bandwidth control with -EBUSY when this situation is found.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 13:10:12 +02:00
Peter Zijlstra
eb755805f2 sched: extract walk_tg_tree()
Extract walk_tg_tree() and make it a little more generic so we can use it
in the schedulablity test.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 13:10:11 +02:00
Peter Zijlstra
0b148fa048 sched: rt-bandwidth group disable fixes
More extensive disable of bandwidth control. It allows sysctl_sched_rt_runtime
to disable full group bandwidth control.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 13:10:10 +02:00
Peter Zijlstra
6f0d5c390e sched: rt-bandwidth accounting fix
It fixes an accounting bug where we would continue accumulating runtime
even though the bandwidth control is disabled. This would lead to very long
throttle periods once bandwidth control gets turned on again.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 13:10:09 +02:00
Peter Zijlstra
af4491e516 sched: rt-bandwidth for user grouping interface
rt_runtime is a signed value

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 13:10:09 +02:00
Hiroshi Shimamoto
0c925d7923 rcuclassic: fix compilation NG
fix:

  CC      kernel/rcuclassic.o
kernel/rcuclassic.c: In function '__rcu_process_callbacks':
kernel/rcuclassic.c:561: error: 'flags' undeclared (first use in this function)
kernel/rcuclassic.c:561: error: (Each undeclared identifier is reported only once
kernel/rcuclassic.c:561: error: for each function it appears in.)

Declare missing variable flags.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 11:03:33 +02:00
Paul E. McKenney
eff9b713ee rcu: fix locking cleanup fallout
Given that the rcp->lock is now acquired from call_rcu(), which can be
invoked from irq-disable regions, all acquisitions need to disable irqs.
The following patch fixes this.

Although I don't have any reason to believe that this is the cause of
Yinghai's oops, it does need to be fixed.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 04:15:36 +02:00
Paul E. McKenney
ded00a56e9 rcu: remove redundant ACCESS_ONCE definition from rcupreempt.c
Remove the redundant definition of ACCESS_ONCE() from rcupreempt.c in
favor of the one in compiler.h.  Also merge the comment header from
rcupreempt.c's definition into that in compiler.h.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-18 09:45:22 +02:00
Dmitry Baryshkov
6951b12a0f lockdep: fix spurious 'inconsistent lock state' warning
Since f82b217e35 lockdep can output spurious
warnings related to hwirqs due to hardirq_off shrinkage from int to bit-sized
flag. Guard it with double negation to fix the warning.

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-18 09:42:31 +02:00
Paul E. McKenney
cd95851785 rcu: fix classic RCU locking cleanup lockdep problem
On Fri, Aug 15, 2008 at 04:24:30PM +0200, Ingo Molnar wrote:
>
> Paul,
>
> one of your two recent RCU patches caused this lockdep splat in -tip
> testing:
>
> ------------------->
> Brought up 2 CPUs
> Total of 2 processors activated (6850.87 BogoMIPS).
> PM: Adding info for No Bus:platform
> khelper used greatest stack depth: 3124 bytes left
>
> =================================
> [ INFO: inconsistent lock state ]
> 2.6.27-rc3-tip #1
> ---------------------------------
> inconsistent {softirq-on-W} -> {in-softirq-W} usage.
> ksoftirqd/0/4 [HC0[0]:SC1[1]:HE1:SE0] takes:
>  (&rcu_ctrlblk.lock){-+..}, at: [<c016d91c>] __rcu_process_callbacks+0x1ac/0x1f0
> {softirq-on-W} state was registered at:
>   [<c01528e4>] __lock_acquire+0x3f4/0x5b0
>   [<c0152b29>] lock_acquire+0x89/0xc0
>   [<c076142b>] _spin_lock+0x3b/0x70
>   [<c016d649>] rcu_init_percpu_data+0x29/0x80
>   [<c075e43f>] rcu_cpu_notify+0xaf/0xd0
>   [<c076458d>] notifier_call_chain+0x2d/0x60
>   [<c0145ede>] __raw_notifier_call_chain+0x1e/0x30
>   [<c075db29>] _cpu_up+0x79/0x110
>   [<c075dc0d>] cpu_up+0x4d/0x70
>   [<c0a769e1>] kernel_init+0xb1/0x200
>   [<c01048a3>] kernel_thread_helper+0x7/0x10
>   [<ffffffff>] 0xffffffff
> irq event stamp: 14
> hardirqs last  enabled at (14): [<c01534db>] trace_hardirqs_on+0xb/0x10
> hardirqs last disabled at (13): [<c014dbeb>] trace_hardirqs_off+0xb/0x10
> softirqs last  enabled at (0): [<c012b186>] copy_process+0x276/0x1190
> softirqs last disabled at (11): [<c0105c0a>] call_on_stack+0x1a/0x30
>
> other info that might help us debug this:
> no locks held by ksoftirqd/0/4.
>
> stack backtrace:
> Pid: 4, comm: ksoftirqd/0 Not tainted 2.6.27-rc3-tip #1
>  [<c01504dc>] print_usage_bug+0x16c/0x1b0
>  [<c0152455>] mark_lock+0xa75/0xb10
>  [<c0108b75>] ? sched_clock+0x15/0x30
>  [<c015289d>] __lock_acquire+0x3ad/0x5b0
>  [<c0152b29>] lock_acquire+0x89/0xc0
>  [<c016d91c>] ? __rcu_process_callbacks+0x1ac/0x1f0
>  [<c076142b>] _spin_lock+0x3b/0x70
>  [<c016d91c>] ? __rcu_process_callbacks+0x1ac/0x1f0
>  [<c016d91c>] __rcu_process_callbacks+0x1ac/0x1f0
>  [<c016d986>] rcu_process_callbacks+0x26/0x50
>  [<c0132305>] __do_softirq+0x95/0x120
>  [<c0132270>] ? __do_softirq+0x0/0x120
>  [<c0105c0a>] call_on_stack+0x1a/0x30
>  [<c0132426>] ? ksoftirqd+0x96/0x110
>  [<c0132390>] ? ksoftirqd+0x0/0x110
>  [<c01411f7>] ? kthread+0x47/0x80
>  [<c01411b0>] ? kthread+0x0/0x80
>  [<c01048a3>] ? kernel_thread_helper+0x7/0x10
>  =======================
> calling  init_cpufreq_transition_notifier_list+0x0/0x20
> initcall init_cpufreq_transition_notifier_list+0x0/0x20 returned 0 after 0 msecs
> calling  net_ns_init+0x0/0x190
> net_namespace: 676 bytes
> initcall net_ns_init+0x0/0x190 returned 0 after 0 msecs
> calling  cpufreq_tsc+0x0/0x20
> initcall cpufreq_tsc+0x0/0x20 returned 0 after 0 msecs
> calling  reboot_init+0x0/0x20
> initcall reboot_init+0x0/0x20 returned 0 after 0 msecs
> calling  print_banner+0x0/0x10
> Booting paravirtualized kernel on bare hardware
>
> <-----------------------
>
> my guess is on:
>
>  commit 1f7b94cd3d
>  Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
>  Date:   Tue Aug 5 09:21:44 2008 -0700
>
>     rcu: classic RCU locking and memory-barrier cleanups
>
> 	Ingo

Fixes a problem detected by lockdep in which rcu->lock was acquired
both in irq context and in process context, but without disabling from
process context.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-17 17:38:01 +02:00
Linus Torvalds
406703f8de Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  lockdep: fix build if CONFIG_PROVE_LOCKING not defined
  lockdep: use WARN() in kernel/lockdep.c
  lockdep: spin_lock_nest_lock(), checkpatch fixes
  lockdep: build fix
2008-08-16 17:16:07 -07:00
Linus Torvalds
c100548d46 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: scale sysctl_sched_shares_ratelimit with nr_cpus
  sched: fix rt-bandwidth hotplug race
  sched: fix the race between walk_tg_tree and sched_create_group
2008-08-16 17:15:32 -07:00
Linus Torvalds
71ef2a46fc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
  security: Fix setting of PF_SUPERPRIV by __capable()
2008-08-15 15:32:13 -07:00
Stephen Hemminger
df60a84418 lockdep: fix build if CONFIG_PROVE_LOCKING not defined
If CONFIG_PROVE_LOCKING not defined, then no dependency information
is available.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15 19:22:04 +02:00
Peter Zijlstra
55cd53404c sched: scale sysctl_sched_shares_ratelimit with nr_cpus
David reported that his Niagra spend a little too much time in
tg_shares_up(), which considering he has a large cpu count makes sense.

So scale the ratelimit value with the number of cpus like we do for
other controls as well.

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15 18:25:07 +02:00
Steven Rostedt
5802294f1b rcu: trace fix possible mem-leak
In the initialization of the RCU trace module, if
rcupreempt_debugfs_init() fails, we never free the the trace buffer.

This patch frees the trace buffer in case the debugfs fails.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Reviewed-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15 17:54:40 +02:00
Dave Chinner
be4de35263 completions: uninline try_wait_for_completion and completion_done
m68k fails to build with these functions inlined in completion.h.  Move
them out of line into sched.c and export them to avoid this problem.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 08:35:44 -07:00
Andrew Morton
8c5a1cf0ad kexec: use a mutex for locking rather than xchg()
Functionally the same, but more conventional.

Cc: Huang Ying <ying.huang@intel.com>
Tested-by: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 08:35:43 -07:00
Huang Ying
3122c33119 kexec jump: fix for ftrace
Ftrace depends on some processor state that we destroyed during kexec and
restored by restore_processor_state().  So save_processor_state() and
restore_processor_state() are moved into machine_kexec() and ftrace is
restored after restore_processor_state().

Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 08:35:43 -07:00
Huang Ying
73bd9c72a2 kexec jump: in sync with hibernation implementation
Add device_pm_lock() and device_pm_unlock() in kernel_kexec() in sync with
current hibernation implementation.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 08:35:42 -07:00
Huang Ying
ca195b7f6d kexec jump: remove duplication of kexec_restart_prepare()
Call kernel_restart_prepare() in kernel_kexec() instead of duplicating the
code.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Pavel Machek <pavel@suse.cz>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 08:35:42 -07:00
Huang Ying
163f6876f5 kexec jump: rename KEXEC_CONTROL_CODE_SIZE to KEXEC_CONTROL_PAGE_SIZE
Rename KEXEC_CONTROL_CODE_SIZE to KEXEC_CONTROL_PAGE_SIZE, because control
page is used for not only code on some platform.  For example in kexec
jump, it is used for data and stack too.

[akpm@linux-foundation.org: unbreak powerpc and arm, finish conversion]
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 08:35:42 -07:00
Huang Ying
7ade3fcc1f kexec jump: clean up #ifdef and comments
Move if (kexec_image->preserve_context) { ...  } into #ifdef
CONFIG_KEXEC_JUMP to make code looks cleaner.

Fix no longer correct comments of kernel_kexec().

Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 08:35:42 -07:00
Huang Ying
4cd69b986e kexec: fix compilation warning on xchg(&kexec_lock, 0) in kernel_kexec()
kernel/kexec.c: In function 'kernel_kexec':
kernel/kexec.c:1506: warning: value computed is not used

Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 08:35:42 -07:00
Paul E. McKenney
1f7b94cd3d rcu: classic RCU locking and memory-barrier cleanups
This patch simplifies the locking and memory-barrier usage in the Classic
RCU grace-period-detection mechanism, incorporating Lai Jiangshan's
feedback from the earlier version (http://lkml.org/lkml/2008/8/1/400
and http://lkml.org/lkml/2008/8/3/43).  Passed 10 hours of
rcutorture concurrent with CPUs being put online and taken offline on
a 128-hardware-thread Power machine.  My apologies to whoever in the
Eastern Hemisphere was planning to use this machine over the Western
Hemisphere night, but it was sitting idle and...

So this is ready for tip/core/rcu.

This patch is in preparation for moving to a hierarchical
algorithm to allow the very large SMP machines -- requested by some
people at OLS, and there seem to have been a few recent patches in the
4096-CPU direction as well.  The general idea is to move to a much more
conservative concurrency design, then apply a hierarchy to reduce
contention on the global lock by a few orders of magnitude (larger
machines would see greater reductions).  The reason for taking a
conservative approach is that this code isn't on any fast path.

Prototype in progress.

This patch is against the linux-tip git tree (tip/core/rcu).  If you
wish to test this against 2.6.26, use the following set of patches:

http://www.rdrop.com/users/paulmck/patches/2.6.26-ljsimp-1.patch
http://www.rdrop.com/users/paulmck/patches/2.6.26-ljsimpfix-3.patch

The first patch combines commits 5127bed588
and 3cac97cbb1 from Lai Jiangshan
<laijs@cn.fujitsu.com>, and the second patch contains my changes.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15 16:08:47 +02:00
Paul E. McKenney
293a17ebc9 rcu: prevent console flood when one CPU sees another AWOL via RCU
One small change needed to keep from flooding the console when one
CPU notices that another is AWOL.  Unless I am missing something subtle.
Otherwise the cleanups look good!

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15 15:08:58 +02:00
Peter Zijlstra
f1679d0848 sched: fix rt-bandwidth hotplug race
When we hot-unplug a cpu and rebuild the sched-domain, all cpus will be
detatched. Alex observed the case where a runqueue was stealing bandwidth
from an already disabled runqueue to satisfy its own needs.

Stop this by skipping over already disabled runqueues.

Reported-by: Alex Nixon <alex.nixon@citrix.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Alex Nixon <alex.nixon@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-14 15:50:58 +02:00
David Howells
5cd9c58fbe security: Fix setting of PF_SUPERPRIV by __capable()
Fix the setting of PF_SUPERPRIV by __capable() as it could corrupt the flags
the target process if that is not the current process and it is trying to
change its own flags in a different way at the same time.

__capable() is using neither atomic ops nor locking to protect t->flags.  This
patch removes __capable() and introduces has_capability() that doesn't set
PF_SUPERPRIV on the process being queried.

This patch further splits security_ptrace() in two:

 (1) security_ptrace_may_access().  This passes judgement on whether one
     process may access another only (PTRACE_MODE_ATTACH for ptrace() and
     PTRACE_MODE_READ for /proc), and takes a pointer to the child process.
     current is the parent.

 (2) security_ptrace_traceme().  This passes judgement on PTRACE_TRACEME only,
     and takes only a pointer to the parent process.  current is the child.

     In Smack and commoncap, this uses has_capability() to determine whether
     the parent will be permitted to use PTRACE_ATTACH if normal checks fail.
     This does not set PF_SUPERPRIV.

Two of the instances of __capable() actually only act on current, and so have
been changed to calls to capable().

Of the places that were using __capable():

 (1) The OOM killer calls __capable() thrice when weighing the killability of a
     process.  All of these now use has_capability().

 (2) cap_ptrace() and smack_ptrace() were using __capable() to check to see
     whether the parent was allowed to trace any process.  As mentioned above,
     these have been split.  For PTRACE_ATTACH and /proc, capable() is now
     used, and for PTRACE_TRACEME, has_capability() is used.

 (3) cap_safe_nice() only ever saw current, so now uses capable().

 (4) smack_setprocattr() rejected accesses to tasks other than current just
     after calling __capable(), so the order of these two tests have been
     switched and capable() is used instead.

 (5) In smack_file_send_sigiotask(), we need to allow privileged processes to
     receive SIGIO on files they're manipulating.

 (6) In smack_task_wait(), we let a process wait for a privileged process,
     whether or not the process doing the waiting is privileged.

I've tested this with the LTP SELinux and syscalls testscripts.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Andrew G. Morgan <morgan@kernel.org>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Morris <jmorris@namei.org>
2008-08-14 22:59:43 +10:00
Ingo Molnar
51ca3c6791 Merge branch 'linus' into x86/core
Conflicts:
	arch/x86/kernel/genapic_64.c
	include/asm-x86/kvm_host.h

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-14 14:58:01 +02:00
Max Krasnyansky
cf417141cb sched, cpuset: rework sched domains and CPU hotplug handling (v4)
This is an updated version of my previous cpuset patch on top of
the latest mainline git.
The patch fixes CPU hotplug handling issues in the current cpusets code.
Namely circular locking in rebuild_sched_domains() and unsafe access to
the cpu_online_map in the cpuset cpu hotplug handler.

This version includes changes suggested by Paul Jackson (naming, comments,
style, etc). I also got rid of the separate workqueue thread because it is
now safe to call get_online_cpus() from workqueue callbacks.

Here are some more details:

rebuild_sched_domains() is the only way to rebuild sched domains
correctly based on the current cpuset settings. What this means
is that we need to be able to call it from different contexts,
like cpu hotplug for example.
Also latest scheduler code in -tip now calls rebuild_sched_domains()
directly from functions like arch_reinit_sched_domains().

In order to support that properly we need to rework cpuset locking
rules to avoid circular dependencies, which is what this patch does.
New lock nesting rules are explained in the comments.
We can now safely call rebuild_sched_domains() from virtually any
context. The only requirement is that it needs to be called under
get_online_cpus(). This allows cpu hotplug handlers and the scheduler
to call rebuild_sched_domains() directly.
The rest of the cpuset code now offloads sched domains rebuilds to
a workqueue (async_rebuild_sched_domains()).

This version of the patch addresses comments from the previous review.
I fixed all miss-formated comments and trailing spaces.

I also factored out the code that builds domain masks and split up CPU and
memory hotplug handling. This was needed to simplify locking, to avoid unsafe
access to the cpu_online_map from mem hotplug handler, and in general to make
things cleaner.

The patch passes moderate testing (building kernel with -j 16, creating &
removing domains and bringing cpus off/online at the same time) on the
quad-core2 based machine.

It passes lockdep checks, even with preemptable RCU enabled.
This time I also tested in with suspend/resume path and everything is working
as expected.

Signed-off-by: Max Krasnyansky <maxk@qualcomm.com>
Acked-by: Paul Jackson <pj@sgi.com>
Cc: menage@google.com
Cc: a.p.zijlstra@chello.nl
Cc: vegard.nossum@gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-14 11:23:51 +02:00
Zhang, Yanmin
09f2724a78 sched: fix the race between walk_tg_tree and sched_create_group
With 2.6.27-rc3, I hit a kernel panic when running volanoMark on my
new x86_64 machine. I also hit it with other 2.6.27-rc kernels.
See below log.

Basically, function walk_tg_tree and sched_create_group have a race
between accessing and initiating tg->children. Below patch fixes it
by moving tg->children initiation to the front of linking tg->siblings
to parent->children.

{----------------panic log------------}

BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
IP: [<ffffffff802292ab>] walk_tg_tree+0x45/0x7f
PGD 1be1c4067 PUD 1bdd8d067 PMD 0
Oops: 0000 [1] SMP
CPU 11
Modules linked in: igb
Pid: 22979, comm: java Not tainted 2.6.27-rc3 #1
RIP: 0010:[<ffffffff802292ab>]  [<ffffffff802292ab>] walk_tg_tree+0x45/0x7f
RSP: 0018:ffff8801bfbbbd18  EFLAGS: 00010083
RAX: 0000000000000000 RBX: ffff8800be0dce40 RCX: ffffffffffffffc0
RDX: ffff880102c43740 RSI: 0000000000000000 RDI: ffff8800be0dce40
RBP: ffff8801bfbbbd48 R08: ffff8800ba437bc8 R09: 0000000000001f40
R10: ffff8801be812100 R11: ffffffff805fdf44 R12: ffff880102c43740
R13: 0000000000000000 R14: ffffffff8022cf0f R15: ffffffff8022749f
FS:  00000000568ac950(0063) GS:ffff8801bfa26d00(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000000 CR3: 00000001bd848000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process java (pid: 22979, threadinfo ffff8801b145a000, task ffff8801bf18e450)
Stack:  0000000000000001 ffff8800ba5c8d60 0000000000000001 0000000000000001
 ffff8800bad1ccb8 0000000000000000 ffff8801bfbbbd98 ffffffff8022ed37
 0000000000000001 0000000000000286 ffff8801bd5ee180 ffff8800ba437bc8
Call Trace:
 <IRQ>  [<ffffffff8022ed37>] try_to_wake_up+0x71/0x24c
 [<ffffffff80247177>] autoremove_wake_function+0x9/0x2e
 [<ffffffff80228039>] ? __wake_up_common+0x46/0x76
 [<ffffffff802296d5>] __wake_up+0x38/0x4f
 [<ffffffff806169cc>] tcp_v4_rcv+0x380/0x62e

Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-14 10:58:48 +02:00
Arjan van de Ven
2df8b1d656 lockdep: use WARN() in kernel/lockdep.c
Use WARN() instead of a printk+WARN_ON() pair; this way the message
becomes part of the warning section for better reporting/collection.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2008-08-13 19:06:46 +02:00
Andrew Morton
c72f4573a5 lockdep: spin_lock_nest_lock(), checkpatch fixes
fix:

 WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
 #46: FILE: kernel/spinlock.c:326:
 +EXPORT_SYMBOL(_spin_lock_nest_lock);

total: 0 errors, 1 warnings, 26 lines checked

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-13 13:56:51 +02:00
Ingo Molnar
73909f7a66 Merge commit 'v2.6.27-rc3' into core/urgent 2008-08-13 13:56:44 +02:00
Ingo Molnar
d6672c5018 lockdep: build fix
fix:

 kernel/built-in.o: In function `lockdep_stats_show':
 lockdep_proc.c:(.text+0x3cb2f): undefined reference to `lockdep_count_forward_deps'
 kernel/built-in.o: In function `l_show':
 lockdep_proc.c:(.text+0x3d02b): undefined reference to `lockdep_count_forward_deps'
 lockdep_proc.c:(.text+0x3d047): undefined reference to `lockdep_count_backward_deps'

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-13 12:55:10 +02:00
Alexey Dobriyan
f18e439d10 genirq: switch /proc/irq/*/smp_affinity et al to seqfiles
Switch /proc/irq/*/smp_affinity , /proc/irq/default_smp_affinity to
seq_files.

cat(1) reads with 1024 chunks by default, with high enough NR_CPUS, there
will be -EINVAL.

As side effect, there are now two less users of the ->read_proc interface.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-12 16:07:30 -07:00
Heiko Carstens
3ee1062b4e cpu hotplug: s390 doesn't support additional_cpus anymore.
s390 doesn't support the additional_cpus kernel parameter anymore since a
long time.  So we better update the code and documentation to reflect
that.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-12 16:07:28 -07:00
Linus Torvalds
96348852cf Merge branch 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  generic-ipi: fix stack and rcu interaction bug in smp_call_function_mask(), fix
2008-08-12 08:49:53 -07:00
Linus Torvalds
1c89ac5501 Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  fix spinlock recursion in hvc_console
  stop_machine: remove unused variable
  modules: extend initcall_debug functionality to the module loader
  export virtio_rng.h
  lguest: use get_user_pages_fast() instead of get_user_pages()
  mm: Make generic weak get_user_pages_fast and EXPORT_GPL it
  lguest: don't set MAC address for guest unless specified
2008-08-12 08:40:19 -07:00
Nick Piggin
c2fc11985d generic-ipi: fix stack and rcu interaction bug in smp_call_function_mask(), fix
> > Nick Piggin (1):
> >       generic-ipi: fix stack and rcu interaction bug in
> > smp_call_function_mask()
>
> I'm still not 100% sure that I have this patch right... I might have seen
> a lockup trace implicating the smp call function path... which may have
> been due to some other problem or a different bug in the new call function
> code, but if some more people can take a look at it before merging?

OK indeed it did have a couple of bugs. Firstly, I wasn't freeing the
data properly in the alloc && wait case. Secondly, I wasn't resetting
CSD_FLAG_WAIT in the for each cpu loop (so only the first CPU would
wait).

After those fixes, the patch boots and runs with the kmalloc commented
out (so it always executes the slowpath).

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-12 11:21:27 +02:00
Li Zefan
ed6d68763b stop_machine: remove unused variable
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-08-12 17:52:55 +10:00
Arjan van de Ven
59f9415ffb modules: extend initcall_debug functionality to the module loader
The kernel has this really nice facility where if you put "initcall_debug"
on the kernel commandline, it'll print which function it's going to
execute just before calling an initcall, and then after the call completes
it will

1) print if it had an error code

2) checks for a few simple bugs (like leaving irqs off)
and

3) print how long the init call took in milliseconds.

While trying to optimize the boot speed of my laptop, I have been loving
number 3 to figure out what to optimize...  ...  and then I wished that
the same thing was done for module loading.

This patch makes the module loader use this exact same functionality; it's
a logical extension in my view (since modules are just sort of late
binding initcalls anyway) and so far I've found it quite useful in finding
where things are too slow in my boot.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-08-12 17:52:54 +10:00
Linus Torvalds
1ea2950884 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched, cpu hotplug: fix set_cpus_allowed() use in hotplug callbacks
  sched: fix mysql+oltp regression
  sched_clock: delay using sched_clock()
  sched clock: couple local and remote clocks
  sched clock: simplify __update_sched_clock()
  sched: eliminate scd->prev_raw
  sched clock: clean up sched_clock_cpu()
  sched clock: revert various sched_clock() changes
  sched: move sched_clock before first use
  sched: test runtime rather than period in global_rt_runtime()
  sched: fix SCHED_HRTICK dependency
  sched: fix warning in hrtick_start_fair()
2008-08-11 16:46:31 -07:00
Linus Torvalds
67a077dca4 Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  posix-timers: fix posix_timer_event() vs dequeue_signal() race
  posix-timers: do_schedule_next_timer: fix the setting of ->si_overrun
2008-08-11 16:46:11 -07:00
Linus Torvalds
9b4d0bab32 Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  lockdep: fix debug_lock_alloc
  lockdep: increase MAX_LOCKDEP_KEYS
  generic-ipi: fix stack and rcu interaction bug in smp_call_function_mask()
  lockdep: fix overflow in the hlock shrinkage code
  lockdep: rename map_[acquire|release]() => lock_map_[acquire|release]()
  lockdep: handle chains involving classes defined in modules
  mm: fix mm_take_all_locks() locking order
  lockdep: annotate mm_take_all_locks()
  lockdep: spin_lock_nest_lock()
  lockdep: lock protection locks
  lockdep: map_acquire
  lockdep: shrink held_lock structure
  lockdep: re-annotate scheduler runqueues
  lockdep: lock_set_subclass - reset a held lock's subclass
  lockdep: change scheduler annotation
  debug_locks: set oops_in_progress if we will log messages.
  lockdep: fix combinatorial explosion in lock subgraph traversal
2008-08-11 16:45:46 -07:00
Ingo Molnar
23a0ee908c Merge branch 'core/locking' into core/urgent 2008-08-12 00:11:49 +02:00
Ingo Molnar
e26b33e955 Merge branch 'sched/clock' into sched/urgent 2008-08-12 00:07:02 +02:00
Peter Zijlstra
0f2bc27be2 lockdep: fix debug_lock_alloc
When we enable DEBUG_LOCK_ALLOC but do not enable PROVE_LOCKING and or
LOCK_STAT, lock_alloc() and lock_release() turn into nops, even though
we should be doing hlock checking (check=1).

This causes a false warning and a lockdep self-disable.

Rectify this.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 22:45:51 +02:00
Dmitry Adamushko
279ef6bbb8 sched, cpu hotplug: fix set_cpus_allowed() use in hotplug callbacks
Mark Langsdorf reported:

> One of my co-workers noticed that the powernow-k8
> driver no longer restarts when a CPU core is
> hot-disabled and then hot-enabled on AMD quad-core
> systems.
>
> The following comands work fine on 2.6.26 and fail
> on 2.6.27-rc1:
>
> echo 0 > /sys/devices/system/cpu/cpu3/online
> echo 1 > /sys/devices/system/cpu/cpu3/online
> find /sys -name cpufreq
>
> For 2.6.26, the find will return a cpufreq
> directory for each processor.  In 2.6.27-rc1,
> the cpu3 directory is missing.
>
> After digging through the code, the following
> logic is failing when the core is hot-enabled
> at runtime.  The code works during the boot
> sequence.
>
>       cpumask_t = current->cpus_allowed;
>       set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
>       if (smp_processor_id() != cpu)
>               return -ENODEV;

So set the CPU active before calling the CPU_ONLINE notifier chain,
there are a handful of notifiers that use set_cpus_allowed().

This fix also solves the problem with x86-microcode. I've sent
alternative patches for microcode, but as this "rely on
set_cpus_allowed_ptr() being workable in cpu-hotplug(CPU_ONLINE, ...)"
assumption seems to be more broad than what we thought, perhaps this fix
should be applied.

With this patch we define that by the moment CPU_ONLINE is being sent,
a 'cpu' is online and ready for tasks to be migrated onto it.

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Reported-by: Mark Langsdorf <mark.langsdorf@amd.com>
Tested-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 16:32:41 +02:00
Nick Piggin
cc7a486cac generic-ipi: fix stack and rcu interaction bug in smp_call_function_mask()
* Venki Pallipadi <venkatesh.pallipadi@intel.com> wrote:

> Found a OOPS on a big SMP box during an overnight reboot test with
> upstream git.
>
> Suresh and I looked at the oops and looks like the root cause is in
> generic_smp_call_function_interrupt() and smp_call_function_mask() with
> wait parameter.
>
> The actual oops looked like
>
> [   11.277260] BUG: unable to handle kernel paging request at ffff8802ffffffff
> [   11.277815] IP: [<ffff8802ffffffff>] 0xffff8802ffffffff
> [   11.278155] PGD 202063 PUD 0
> [   11.278576] Oops: 0010 [1] SMP
> [   11.279006] CPU 5
> [   11.279336] Modules linked in:
> [   11.279752] Pid: 0, comm: swapper Not tainted 2.6.27-rc2-00020-g685d87f #290
> [   11.280039] RIP: 0010:[<ffff8802ffffffff>]  [<ffff8802ffffffff>] 0xffff8802ffffffff
> [   11.280692] RSP: 0018:ffff88027f1f7f70  EFLAGS: 00010086
> [   11.280976] RAX: 00000000ffffffff RBX: 0000000000000000 RCX: 0000000000000000
> [   11.281264] RDX: 0000000000004f4e RSI: 0000000000000001 RDI: 0000000000000000
> [   11.281624] RBP: ffff88027f1f7f98 R08: 0000000000000001 R09: ffffffff802509af
> [   11.281925] R10: ffff8800280c2780 R11: 0000000000000000 R12: ffff88027f097d48
> [   11.282214] R13: ffff88027f097d70 R14: 0000000000000005 R15: ffff88027e571000
> [   11.282502] FS:  0000000000000000(0000) GS:ffff88027f1c3340(0000) knlGS:0000000000000000
> [   11.283096] CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
> [   11.283382] CR2: ffff8802ffffffff CR3: 0000000000201000 CR4: 00000000000006e0
> [   11.283760] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [   11.284048] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> [   11.284337] Process swapper (pid: 0, threadinfo ffff88027f1f2000, task ffff88027f1f0640)
> [   11.284936] Stack:  ffffffff80250963 0000000000000212 0000000000ee8c78 0000000000ee8a66
> [   11.285802]  ffff88027e571550 ffff88027f1f7fa8 ffffffff8021adb5 ffff88027f1f3e40
> [   11.286599]  ffffffff8020bdd6 ffff88027f1f3e40 <EOI>  ffff88027f1f3ef8 0000000000000000
> [   11.287120] Call Trace:
> [   11.287768]  <IRQ>  [<ffffffff80250963>] ? generic_smp_call_function_interrupt+0x61/0x12c
> [   11.288354]  [<ffffffff8021adb5>] smp_call_function_interrupt+0x17/0x27
> [   11.288744]  [<ffffffff8020bdd6>] call_function_interrupt+0x66/0x70
> [   11.289030]  <EOI>  [<ffffffff8024ab3b>] ? clockevents_notify+0x19/0x73
> [   11.289380]  [<ffffffff803b9b75>] ? acpi_idle_enter_simple+0x18b/0x1fa
> [   11.289760]  [<ffffffff803b9b6b>] ? acpi_idle_enter_simple+0x181/0x1fa
> [   11.290051]  [<ffffffff8053aeca>] ? cpuidle_idle_call+0x70/0xa2
> [   11.290338]  [<ffffffff80209f61>] ? cpu_idle+0x5f/0x7d
> [   11.290723]  [<ffffffff8060224a>] ? start_secondary+0x14d/0x152
> [   11.291010]
> [   11.291287]
> [   11.291654] Code:  Bad RIP value.
> [   11.292041] RIP  [<ffff8802ffffffff>] 0xffff8802ffffffff
> [   11.292380]  RSP <ffff88027f1f7f70>
> [   11.292741] CR2: ffff8802ffffffff
> [   11.310951] ---[ end trace 137c54d525305f1c ]---
>
> The problem is with the following sequence of events:
>
> - CPU A calls smp_call_function_mask() for CPU B with wait parameter
> - CPU A sets up the call_function_data on the stack and does an rcu add to
>   call_function_queue
> - CPU A waits until the WAIT flag is cleared
> - CPU B gets the call function interrupt and starts going through the
>   call_function_queue
> - CPU C also gets some other call function interrupt and starts going through
>   the call_function_queue
> - CPU C, which is also going through the call_function_queue, starts referencing
>   CPU A's stack, as that element is still in call_function_queue
> - CPU B finishes the function call that CPU A set up and as there are no other
>   references to it, rcu deletes the call_function_data (which was from CPU A
>   stack)
> - CPU B sees the wait flag and just clears the flag (no call_rcu to free)
> - CPU A which was waiting on the flag continues executing and the stack
>   contents change
>
> - CPU C is still in rcu_read section accessing the CPU A's stack sees
>   inconsistent call_funation_data and can try to execute
>   function with some random pointer, causing stack corruption for A
>   (by clearing the bits in mask field) and oops.

Nice debugging work.

I'd suggest something like the attached (boot tested) patch as the simple
fix for now.

I expect the benefits from the less synchronized, multiple-in-flight-data
global queue will still outweigh the costs of dynamic allocations. But
if worst comes to worst then we just go back to a globally synchronous
one-at-a-time implementation, but that would be pretty sad!

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 15:21:28 +02:00
Mike Galbraith
77ae651347 sched: fix mysql+oltp regression
Defer commit 6d299f1b53 to the next release.

Testing of the tip/sched/clock tree revealed a mysql+oltp regression
which bisection eventually traced back to this commit in mainline.

Pertinent test results:  Three run sysbench averages, throughput units
in read/write requests/sec.

clients         1     2     4     8    16    32    64
6e0534f      9646 17876 34774 33868 32230 30767 29441
2.6.26.1     9112 17936 34652 33383 31929 30665 29232
6d299f1      9112 14637 28370 33339 32038 30762 29204

Note: subsequent commits hide the majority of this regression until you
apply the clock fixes, at which time it reemerges at full magnitude.

We cannot see anything bad about the change itself so we defer it to the
next release until this problem is fully analysed.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 14:49:29 +02:00
Ingo Molnar
251a169c69 Merge branch 'linus' into sched/urgent 2008-08-11 13:40:56 +02:00
Ingo Molnar
78635fc739 rcu, debug: detect stalled grace periods, cleanups
small cleanups.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 13:35:18 +02:00
Paul E. McKenney
67182ae1c4 rcu, debug: detect stalled grace periods
this is a diagnostic patch for Classic RCU.

The approach is to record a timestamp at the beginning
of the grace period (in rcu_start_batch()), then have
rcu_check_callbacks() complain if:

 1.	it is running on a CPU that has holding up grace periods for
 	a long time (say one second).  This will identify the culprit
 	assuming that the culprit has not disabled hardware irqs,
 	instruction execution, or some such.

 2.	it is running on a CPU that is not holding up grace periods,
 	but grace periods have been held up for an even longer time
 	(say two seconds).

It is enabled via the default-off CONFIG_DEBUG_RCU_STALL kernel parameter.

Rather than exponential backoff, it backs off to once per 30 seconds.
My feeling upon thinking on it was that if you have stalled RCU grace
periods for that long, a few extra printk() messages are probably the
least of your worries...

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: David Witbrodt <dawitbro@sbcglobal.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 13:35:18 +02:00
Ingo Molnar
c4c0c56a7a Merge branch 'linus' into core/rcu 2008-08-11 13:27:47 +02:00
Ingo Molnar
3295f0ef9f lockdep: rename map_[acquire|release]() => lock_map_[acquire|release]()
the names were too generic:

 drivers/uio/uio.c:87: error: expected identifier or '(' before 'do'
 drivers/uio/uio.c:87: error: expected identifier or '(' before 'while'
 drivers/uio/uio.c:113: error: 'map_release' undeclared here (not in a function)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 10:30:30 +02:00
Rabin Vincent
8bfe0298f7 lockdep: handle chains involving classes defined in modules
Solve this by marking the classes as unused and not printing information
about the unused classes.

Reported-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Rabin Vincent <rabin@rab.in>
Acked-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 09:30:26 +02:00
Peter Zijlstra
b7d39aff91 lockdep: spin_lock_nest_lock()
Expose the new lock protection lock.

This can be used to annotate places where we take multiple locks of the
same class and avoid deadlocks by always taking another (top-level) lock
first.

NOTE: we're still bound to the MAX_LOCK_DEPTH (48) limit.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 09:30:24 +02:00
Peter Zijlstra
7531e2f34d lockdep: lock protection locks
On Fri, 2008-08-01 at 16:26 -0700, Linus Torvalds wrote:

> On Fri, 1 Aug 2008, David Miller wrote:
> >
> > Taking more than a few locks of the same class at once is bad
> > news and it's better to find an alternative method.
>
> It's not always wrong.
>
> If you can guarantee that anybody that takes more than one lock of a
> particular class will always take a single top-level lock _first_, then
> that's all good. You can obviously screw up and take the same lock _twice_
> (which will deadlock), but at least you cannot get into ABBA situations.
>
> So maybe the right thing to do is to just teach lockdep about "lock
> protection locks". That would have solved the multi-queue issues for
> networking too - all the actual network drivers would still have taken
> just their single queue lock, but the one case that needs to take all of
> them would have taken a separate top-level lock first.
>
> Never mind that the multi-queue locks were always taken in the same order:
> it's never wrong to just have some top-level serialization, and anybody
> who needs to take <n> locks might as well do <n+1>, because they sure as
> hell aren't going to be on _any_ fastpaths.
>
> So the simplest solution really sounds like just teaching lockdep about
> that one special case. It's not "nesting" exactly, although it's obviously
> related to it.

Do as Linus suggested. The lock protection lock is called nest_lock.

Note that we still have the MAX_LOCK_DEPTH (48) limit to consider, so anything
that spills that it still up shit creek.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 09:30:24 +02:00
Peter Zijlstra
4f3e7524b2 lockdep: map_acquire
Most the free-standing lock_acquire() usages look remarkably similar, sweep
them into a new helper.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 09:30:23 +02:00
Dave Jones
f82b217e35 lockdep: shrink held_lock structure
struct held_lock {
        u64                        prev_chain_key;       /*     0     8 */
        struct lock_class *        class;                /*     8     8 */
        long unsigned int          acquire_ip;           /*    16     8 */
        struct lockdep_map *       instance;             /*    24     8 */
        int                        irq_context;          /*    32     4 */
        int                        trylock;              /*    36     4 */
        int                        read;                 /*    40     4 */
        int                        check;                /*    44     4 */
        int                        hardirqs_off;         /*    48     4 */

        /* size: 56, cachelines: 1 */
        /* padding: 4 */
        /* last cacheline: 56 bytes */
};

struct held_lock {
        u64                        prev_chain_key;       /*     0     8 */
        long unsigned int          acquire_ip;           /*     8     8 */
        struct lockdep_map *       instance;             /*    16     8 */
        unsigned int               class_idx:11;         /*    24:21  4 */
        unsigned int               irq_context:2;        /*    24:19  4 */
        unsigned int               trylock:1;            /*    24:18  4 */
        unsigned int               read:2;               /*    24:16  4 */
        unsigned int               check:2;              /*    24:14  4 */
        unsigned int               hardirqs_off:1;       /*    24:13  4 */

        /* size: 32, cachelines: 1 */
        /* padding: 4 */
        /* bit_padding: 13 bits */
        /* last cacheline: 32 bytes */
};

[mingo@elte.hu: shrunk hlock->class too]
[peterz@infradead.org: fixup bit sizes]
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2008-08-11 09:30:23 +02:00
Peter Zijlstra
1b12bbc747 lockdep: re-annotate scheduler runqueues
Instead of using a per-rq lock class, use the regular nesting operations.

However, take extra care with double_lock_balance() as it can release the
already held rq->lock (and therefore change its nesting class).

So what can happen is:

 spin_lock(rq->lock);	// this rq subclass 0

 double_lock_balance(rq, other_rq);
   // release rq
   // acquire other_rq->lock subclass 0
   // acquire rq->lock subclass 1

 spin_unlock(other_rq->lock);

leaving you with rq->lock in subclass 1

So a subsequent double_lock_balance() call can try to nest a subclass 1
lock while already holding a subclass 1 lock.

Fix this by introducing double_unlock_balance() which releases the other
rq's lock, but also re-sets the subclass for this rq's lock to 0.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 09:30:22 +02:00
Peter Zijlstra
64aa348edc lockdep: lock_set_subclass - reset a held lock's subclass
this can be used to reset a held lock's subclass, for arbitrary-depth
iterated data structures such as trees or lists which have per-node
locks.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 09:30:21 +02:00
Ingo Molnar
cf206bffbb Merge branch 'linus' into sched/clock 2008-08-11 08:59:21 +02:00
Peter Zijlstra
c1955a3d47 sched_clock: delay using sched_clock()
Some arch's can't handle sched_clock() being called too early - delay
this until sched_clock_init() has been called.

Reported-by: Bill Gatliff <bgat@billgatliff.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Nishanth Aravamudan <nacc@us.ibm.com>
CC: Russell King - ARM Linux <linux@arm.linux.org.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 08:59:03 +02:00
Dmitry Baryshkov
cb3952bf78 DMA: make dma-coherent.c documentation kdoc-friendly
Spotted by Randy.

Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-08-07 06:52:01 -07:00
Richard Hughes
bf1db69fbf pm_qos: spelling fixes
A documentation cleanup patch.  With a minor tweak to clarify units for
kbs.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: mark gross <mgross@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-05 14:33:50 -07:00
Jan Beulich
d2dc1f4adb dma: fix order calculation in dma_mark_declared_memory_occupied()
get_order() takes byte-sized input, not a page-granular one.

Irrespective of this fix I'm inclined to believe that this doesn't work
right anyway - bitmap_allocate_region() has an implicit assumption of
'pos' being suitable for 'order', which this function doesn't seem to
enforce (and since it's being called with a byte-granular value there's no
reason to believe that the callers would make sure device_addr is passed
accordingly - it's also not documented that way).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-05 14:33:49 -07:00
David Brownell
c69ad71bcd genirq: better warning on irqchip->set_type() failure
While I'm glad to finally see the hole fixed whereby passing an invalid
IRQ trigger type to request_irq() would be ignored, the current diagnostic
isn't quite useful.  Fixed by also listing the trigger type which was
rejected.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-05 14:33:47 -07:00
Oleg Nesterov
5b2becc8cf semaphore: __down_common: use signal_pending_state()
Change __down_common() to use signal_pending_state() instead of open
coding.

The changes in kernel/semaphore.o are just artifacts, the state checks are
optimized away.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-05 14:33:47 -07:00
Tom Zanussi
3219445033 relay: fix "full buffer with exactly full last subbuffer" accounting problem
In relay's current read implementation, if the buffer is completely full
but hasn't triggered the buffer-full condition (i.e. the last write
didn't cross the subbuffer boundary) and the last subbuffer is exactly
full, the subbuffer accounting code erroneously finds nothing available.
This patch fixes the problem.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org>
Cc: Andrea Righi <righi.andrea@gmail.com>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-05 14:33:46 -07:00
Linus Torvalds
b13ad6f47c Merge branch 'audit.b56' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current
* 'audit.b56' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
  Re: [PATCH] Fix the kernel panic of audit_filter_task when key field is set
2008-08-04 17:21:38 -07:00
Jeremy Fitzhardinge
725aad24c3 __sched_setscheduler: don't do any policy checks when not "user"
The "user" parameter to __sched_setscheduler indicates whether the
change is being done on behalf of a user process or not.  If not, we
shouldn't apply any permissions checks, so don't call
security_task_setscheduler().

Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-04 17:16:20 -07:00
zhangxiliang
1a61c88def Re: [PATCH] Fix the kernel panic of audit_filter_task when key field is set
Sorry, I miss a blank between if and "(".
And I add "unlikely" to check "ctx" in audit_match_perm() and audit_match_filetype().
This is a new patch for it.

Signed-off-by: Zhang Xiliang <zhangxiliang@cn.fujitsu.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-08-04 06:13:50 -04:00
Roland McGrath
5c7edcd7ee tracehook: fix exit_signal=0 case
My commit 2b2a1ff64a introduced a regression
(sorry about that) for the odd case of exit_signal=0 (e.g. clone_flags=0).
This is not a normal use, but it's used by a case in the glibc test suite.

Dying with exit_signal=0 sends no signal, but it's supposed to wake up a
parent's blocked wait*() calls (unlike the delayed_group_leader case).
This fixes tracehook_notify_death() and its caller to distinguish a
"signal 0" wakeup from the delayed_group_leader case (with no wakeup).

Signed-off-by: Roland McGrath <roland@redhat.com>
Tested-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-01 12:01:11 -07:00
Linus Torvalds
5adf2b03d9 Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  locking: fix mutex @key parameter kernel-doc notation
2008-08-01 11:52:39 -07:00
Linus Torvalds
31582b094d Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  kgdb: fix gdb serial thread queries
  kgdb: fix kgdb_validate_break_address to perform a mem write
  kgdb: remove the requirement for CONFIG_FRAME_POINTER
2008-08-01 11:45:09 -07:00
zhangxiliang
20c6aaa39a [PATCH] Fix the bug of using AUDIT_STATUS_RATE_LIMIT when set fail, no error output.
When the "status_get->mask" is "AUDIT_STATUS_RATE_LIMIT || AUDIT_STATUS_BACKLOG_LIMIT".
If "audit_set_rate_limit" fails and "audit_set_backlog_limit" succeeds, the "err" value
will be greater than or equal to 0. It will miss the failure of rate set.

Signed-off-by: Zhang Xiliang <zhangxiliang@cn.fujitsu.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-08-01 12:15:16 -04:00
zhangxiliang
980dfb0db3 [PATCH] Fix the kernel panic of audit_filter_task when key field is set
When calling audit_filter_task(), it calls audit_filter_rules() with audit_context is NULL.
If the key field is set, the result in audit_filter_rules() will be set to 1 and
ctx->filterkey will be set to key.
But the ctx is NULL in this condition, so kernel will panic.

Signed-off-by: Zhang Xiliang <zhangxiliang@cn.fujitsu.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-08-01 12:15:03 -04:00
zhangxiliang
036bbf76ad Re: [PATCH] the loginuid field should be output in all AUDIT_CONFIG_CHANGE audit messages
> shouldn't these be using the "audit_get_loginuid(current)"  and if we
> are going to output loginuid we also should be outputting sessionid

Thanks for your detailed explanation.
I have made a new patch for outputing "loginuid" and "sessionid" by audit_get_loginuid(current) and audit_get_sessionid(current).
If there are some deficiencies, please give me your indication.

Signed-off-by: Zhang Xiliang <zhangxiliang@cn.fujitsu.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-08-01 12:15:03 -04:00
Vesa-Matti J Kari
1d6c9649e2 kernel/audit.c control character detection is off-by-one
Hello,

According to my understanding there is an off-by-one bug in the
function:

   audit_string_contains_control()

in:

  kernel/audit.c

Patch is included.

I do not know from how many places the function is called from, but for
example, SELinux Access Vector Cache tries to log untrusted filenames via
call path:

avc_audit()
     audit_log_untrustedstring()
         audit_log_n_untrustedstring()
             audit_string_contains_control()

If audit_string_contains_control() detects control characters, then the
string is hex-encoded. But the hex=0x7f dec=127, DEL-character, is not
detected.

I guess this could have at least some minor security implications, since a
user can create a filename with 0x7f in it, causing logged filename to
possibly look different when someone reads it on the terminal.

Signed-off-by: Vesa-Matti Kari <vmkari@cc.helsinki.fi>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-08-01 12:05:35 -04:00
Eric Paris
ee1d315663 [PATCH] Audit: Collect signal info when SIGUSR2 is sent to auditd
Makes the kernel audit subsystem collect information about the sending
process when that process sends SIGUSR2 to the userspace audit daemon.
SIGUSR2 is a new interesting signal to auditd telling auditd that it
should try to start logging to disk again and the error condition which
caused it to stop logging to disk (usually out of space) has been
rectified.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-08-01 12:05:32 -04:00
Jason Wessel
25fc999913 kgdb: fix gdb serial thread queries
The command "info threads" did not work correctly with kgdb.  It would
result in a silent kernel hang if used.

This patach addresses several problems.
 - Fix use of deprecated NR_CPUS
 - Fix kgdb to not walk linearly through the pid space
 - Correctly implement shadow pids
 - Change the threads per query to a #define
 - Fix kgdb_hex2long to work with negated values

The threads 0 and -1 are reserved to represent the current task.  That
means that CPU 0 will start with a shadow thread id of -2, and CPU 1
will have a shadow thread id of -3, etc...

From the debugger you can switch to a shadow thread to see what one of
the other cpus was doing, however it is not possible to execute run
control operations on any other cpu execept the cpu executing the
kgdb_handle_exception().

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2008-08-01 08:39:35 -05:00
Jason Wessel
a9b60bf4c2 kgdb: fix kgdb_validate_break_address to perform a mem write
A regression to the kgdb core was found in the case of using the
CONFIG_DEBUG_RODATA kernel option.  When this option is on, a breakpoint
cannot be written into any readonly memory page.  When an external
debugger requests a breakpoint to get set, the
kgdb_validate_break_address() was only checking to see if the address
to place the breakpoint was readable and lacked a write check.

This patch changes the validate routine to try reading (via the
breakpoint set request) and also to try immediately writing the break
point.  If either fails, an error is correctly returned and the
debugger behaves correctly.  Then an end user can make the
descision to use hardware breakpoints.

Also update the documentation to reflect that using
CONFIG_DEBUG_RODATA will inhibit the use of software breakpoints.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2008-08-01 08:39:34 -05:00
Peter Zijlstra
5e710e37bd lockdep: change scheduler annotation
While thinking about David's graph walk lockdep patch it _finally_
dawned on me that there is no reason we have a lock class per cpu ...

Sorry for being dense :-/

The below changes the annotation from a lock class per cpu, to a single
nested lock, as the scheduler never holds more that 2 rq locks at a time
anyway.

If there was code requiring holding all rq locks this would not work and
the original annotation would be the only option, but that not being the
case, this is a much lighter one.

Compiles and boots on a 2-way x86_64.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-01 10:46:48 +02:00
David Miller
419ca3f135 lockdep: fix combinatorial explosion in lock subgraph traversal
When we traverse the graph, either forwards or backwards, we
are interested in whether a certain property exists somewhere
in a node reachable in the graph.

Therefore it is never necessary to traverse through a node more
than once to get a correct answer to the given query.

Take advantage of this property using a global ID counter so that we
need not clear all the markers in all the lock_class entries before
doing a traversal.  A new ID is choosen when we start to traverse, and
we continue through a lock_class only if it's ID hasn't been marked
with the new value yet.

This short-circuiting is essential especially for high CPU count
systems.  The scheduler has a runqueue per cpu, and needs to take
two runqueue locks at a time, which leads to long chains of
backwards and forwards subgraphs from these runqueue lock nodes.
Without the short-circuit implemented here, a graph traversal on
a runqueue lock can take up to (1 << (N - 1)) checks on a system
with N cpus.

For anything more than 16 cpus or so, lockdep will eventually bring
the machine to a complete standstill.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-31 18:38:28 +02:00
Ingo Molnar
6679ce6e5f Merge branch 'linus' into sched/urgent 2008-07-31 18:34:22 +02:00
Ingo Molnar
4a273f209c sched clock: couple local and remote clocks
When taking the time of a remote CPU, use the opportunity to
couple (sync) the clocks to each other. (in a monotonic way)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Mike Galbraith <efault@gmx.de>
2008-07-31 17:21:01 +02:00
Ingo Molnar
56b906126d sched clock: simplify __update_sched_clock()
- return the current clock instead of letting callers
  fetch it from scd->clock

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Mike Galbraith <efault@gmx.de>
2008-07-31 17:20:55 +02:00
Ingo Molnar
18e4e36c66 sched: eliminate scd->prev_raw
eliminate prev_raw and use tick_raw instead.

It's enough to base the current time on the scheduler tick timestamp
alone - the monotonicity and maximum checks will prevent any damage.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Mike Galbraith <efault@gmx.de>
2008-07-31 17:20:49 +02:00