Commit Graph

753 Commits

Author SHA1 Message Date
Linus Torvalds
7fda0412c5 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar.

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpusets: Remove an unused variable
  sched/rt: Improve pick_next_highest_task_rt()
  sched: Fix select_fallback_rq() vs cpu_active/cpu_online
  sched/x86/smp: Do not enable IRQs over calibrate_delay()
  sched: Fix compiler warning about declared inline after use
  MAINTAINERS: Update email address for SCHEDULER and PERF EVENTS
2012-03-29 14:46:05 -07:00
Ingo Molnar
1f56ee7b68 Merge branch 'sched/arch' into sched/urgent
Merge reason: It has not gone upstream via the ARM tree, merge it via
              the scheduler tree.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-29 12:48:22 +02:00
Stephen Boyd
6135fc1eb4 sched: Fix __schedule_bug() output when called from an interrupt
If schedule is called from an interrupt handler __schedule_bug()
will call show_regs() with the registers saved during the
interrupt handling done in do_IRQ(). This means we'll see the
registers and the backtrace for the process that was interrupted
and not the full backtrace explaining who called schedule().

This is due to 838225b ("sched: use show_regs() to improve
__schedule_bug() output", 2007-10-24) which improperly assumed
that get_irq_regs() would return the registers for the current
stack because it is being called from within an interrupt
handler. Simply remove the show_reg() code so that we dump a
backtrace for the interrupt handler that called schedule().

[ I ran across this when I was presented with a scheduling while
  atomic log with a stacktrace pointing at spin_unlock_irqrestore().
  It made no sense and I had to guess what interrupt handler could
  be called and poke around for someone calling schedule() in an
  interrupt handler. A simple test of putting an msleep() in
  an interrupt handler works better with this patch because you
  can actually see the msleep() call in the backtrace. ]

Also-reported-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Satyam Sharma <satyam@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1332979847-27102-1-git-send-email-sboyd@codeaurora.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-03-29 08:34:45 +02:00
David Howells
96f951edb1 Add #includes needed to permit the removal of asm/system.h
asm/system.h is a cause of circular dependency problems because it contains
commonly used primitive stuff like barrier definitions and uncommonly used
stuff like switch_to() that might require MMU definitions.

asm/system.h has been disintegrated by this point on all arches into the
following common segments:

 (1) asm/barrier.h

     Moved memory barrier definitions here.

 (2) asm/cmpxchg.h

     Moved xchg() and cmpxchg() here.  #included in asm/atomic.h.

 (3) asm/bug.h

     Moved die() and similar here.

 (4) asm/exec.h

     Moved arch_align_stack() here.

 (5) asm/elf.h

     Moved AT_VECTOR_SIZE_ARCH here.

 (6) asm/switch_to.h

     Moved switch_to() here.

Signed-off-by: David Howells <dhowells@redhat.com>
2012-03-28 18:30:03 +01:00
Peter Zijlstra
2baab4e904 sched: Fix select_fallback_rq() vs cpu_active/cpu_online
Commit 5fbd036b55 ("sched: Cleanup cpu_active madness"), which was
supposed to finally sort the cpu_active mess, instead uncovered more.

Since CPU_STARTING is ran before setting the cpu online, there's a
(small) window where the cpu has active,!online.

If during this time there's a wakeup of a task that used to reside on
that cpu select_task_rq() will use select_fallback_rq() to compute an
alternative cpu to run on since we find !online.

select_fallback_rq() however will compute the new cpu against
cpu_active, this means that it can return the same cpu it started out
with, the !online one, since that cpu is in fact marked active.

This results in us trying to scheduling a task on an offline cpu and
triggering a WARN in the IPI code.

The solution proposed by Chuansheng Liu of setting cpu_active in
set_cpu_online() is buggy, firstly not all archs actually use
set_cpu_online(), secondly, not all archs call set_cpu_online() with
IRQs disabled, this means we would introduce either the same race or
the race from fd8a7de17 ("x86: cpu-hotplug: Prevent softirq wakeup on
wrong CPU") -- albeit much narrower.

[ By setting online first and active later we have a window of
  online,!active, fresh and bound kthreads have task_cpu() of 0 and
  since cpu0 isn't in tsk_cpus_allowed() we end up in
  select_fallback_rq() which excludes !active, resulting in a reset
  of ->cpus_allowed and the thread running all over the place. ]

The solution is to re-work select_fallback_rq() to require active
_and_ online. This makes the active,!online case work as expected,
OTOH archs running CPU_STARTING after setting online are now
vulnerable to the issue from fd8a7de17 -- these are alpha and
blackfin.

Reported-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: linux-alpha@vger.kernel.org
Link: http://lkml.kernel.org/n/tip-hubqk1i10o4dpvlm06gq7v6j@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-03-27 14:50:14 +02:00
Linus Torvalds
3556485f15 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates for 3.4 from James Morris:
 "The main addition here is the new Yama security module from Kees Cook,
  which was discussed at the Linux Security Summit last year.  Its
  purpose is to collect miscellaneous DAC security enhancements in one
  place.  This also marks a departure in policy for LSM modules, which
  were previously limited to being standalone access control systems.
  Chromium OS is using Yama, and I believe there are plans for Ubuntu,
  at least.

  This patchset also includes maintenance updates for AppArmor, TOMOYO
  and others."

Fix trivial conflict in <net/sock.h> due to the jumo_label->static_key
rename.

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (38 commits)
  AppArmor: Fix location of const qualifier on generated string tables
  TOMOYO: Return error if fails to delete a domain
  AppArmor: add const qualifiers to string arrays
  AppArmor: Add ability to load extended policy
  TOMOYO: Return appropriate value to poll().
  AppArmor: Move path failure information into aa_get_name and rename
  AppArmor: Update dfa matching routines.
  AppArmor: Minor cleanup of d_namespace_path to consolidate error handling
  AppArmor: Retrieve the dentry_path for error reporting when path lookup fails
  AppArmor: Add const qualifiers to generated string tables
  AppArmor: Fix oops in policy unpack auditing
  AppArmor: Fix error returned when a path lookup is disconnected
  KEYS: testing wrong bit for KEY_FLAG_REVOKED
  TOMOYO: Fix mount flags checking order.
  security: fix ima kconfig warning
  AppArmor: Fix the error case for chroot relative path name lookup
  AppArmor: fix mapping of META_READ to audit and quiet flags
  AppArmor: Fix underflow in xindex calculation
  AppArmor: Fix dropping of allowed operations that are force audited
  AppArmor: Add mising end of structure test to caps unpacking
  ...
2012-03-21 13:25:04 -07:00
Linus Torvalds
0d9cabdcce Merge branch 'for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup changes from Tejun Heo:
 "Out of the 8 commits, one fixes a long-standing locking issue around
  tasklist walking and others are cleanups."

* 'for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: Walk task list under tasklist_lock in cgroup_enable_task_cg_list
  cgroup: Remove wrong comment on cgroup_enable_task_cg_list()
  cgroup: remove cgroup_subsys argument from callbacks
  cgroup: remove extra calls to find_existing_css_set
  cgroup: replace tasklist_lock with rcu_read_lock
  cgroup: simplify double-check locking in cgroup_attach_proc
  cgroup: move struct cgroup_pidlist out from the header file
  cgroup: remove cgroup_attach_task_current_cg()
2012-03-20 18:11:21 -07:00
Linus Torvalds
2ba68940c8 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes for v3.4 from Ingo Molnar

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
  printk: Make it compile with !CONFIG_PRINTK
  sched/x86: Fix overflow in cyc2ns_offset
  sched: Fix nohz load accounting -- again!
  sched: Update yield() docs
  printk/sched: Introduce special printk_sched() for those awkward moments
  sched/nohz: Correctly initialize 'next_balance' in 'nohz' idle balancer
  sched: Cleanup cpu_active madness
  sched: Fix load-balance wreckage
  sched: Clean up parameter passing of proc_sched_autogroup_set_nice()
  sched: Ditch per cgroup task lists for load-balancing
  sched: Rename load-balancing fields
  sched: Move load-balancing arguments into helper struct
  sched/rt: Do not submit new work when PI-blocked
  sched/rt: Prevent idle task boosting
  sched/wait: Add __wake_up_all_locked() API
  sched/rt: Document scheduler related skip-resched-check sites
  sched/rt: Use schedule_preempt_disabled()
  sched/rt: Add schedule_preempt_disabled()
  sched/rt: Do not throttle when PI boosting
  sched/rt: Keep period timer ticking when rt throttling is active
  ...
2012-03-20 10:31:44 -07:00
Catalin Marinas
01f23e1630 sched/arch: Introduce the finish_arch_post_lock_switch() scheduler callback
This callback is called by the scheduler after rq->lock has been released
and interrupts enabled. It will be used in subsequent patches on the ARM
architecture.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Frank Rowand <frank.rowand@am.sony.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Tested-by: Marc Zyngier <Marc.Zyngier@arm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/20120313110840.7b444deb6b1bb902c15f3cdf@canb.auug.org.au
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-13 10:17:45 +01:00
Peter Zijlstra
c308b56b53 sched: Fix nohz load accounting -- again!
Various people reported nohz load tracking still being wrecked, but Doug
spotted the actual problem. We fold the nohz remainder in too soon,
causing us to loose samples and under-account.

So instead of playing catch-up up-front, always do a single load-fold
with whatever state we encounter and only then fold the nohz remainder
and play catch-up.

Reported-by: Doug Smythies <dsmythies@telus.net>
Reported-by: LesÅ=82aw Kope=C4=87 <leslaw.kopec@nasza-klasa.pl>
Reported-by: Aman Gupta <aman@tmm1.net>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-4v31etnhgg9kwd6ocgx3rxl8@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-12 20:43:17 +01:00
Peter Zijlstra
8e3fabfde4 sched: Update yield() docs
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1331056466.11248.327.camel@twins
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-12 20:43:17 +01:00
Peter Zijlstra
3ccf3e8306 printk/sched: Introduce special printk_sched() for those awkward moments
There's a few awkward printk()s inside of scheduler guts that people
prefer to keep but really are rather deadlock prone. Fudge around it
by storing the text in a per-cpu buffer and poll it using the existing
printk_tick() handler.

This will drop output when its more frequent than once a tick, however
only the affinity thing could possible go that fast and for that just
one should suffice to notify the admin he's done something silly..

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-wua3lmkt3dg8nfts66o6brne@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-12 20:43:16 +01:00
Peter Zijlstra
5fbd036b55 sched: Cleanup cpu_active madness
Stepan found:

CPU0		CPUn

_cpu_up()
  __cpu_up()

		boostrap()
		  notify_cpu_starting()
		  set_cpu_online()
		  while (!cpu_active())
		    cpu_relax()

<PREEMPT-out>

smp_call_function(.wait=1)
  /* we find cpu_online() is true */
  arch_send_call_function_ipi_mask()

  /* wait-forever-more */

<PREEMPT-in>
		  local_irq_enable()

  cpu_notify(CPU_ONLINE)
    sched_cpu_active()
      set_cpu_active()

Now the purpose of cpu_active is mostly with bringing down a cpu, where
we mark it !active to avoid the load-balancer from moving tasks to it
while we tear down the cpu. This is required because we only update the
sched_domain tree after we brought the cpu-down. And this is needed so
that some tasks can still run while we bring it down, we just don't want
new tasks to appear.

On cpu-up however the sched_domain tree doesn't yet include the new cpu,
so its invisible to the load-balancer, regardless of the active state.
So instead of setting the active state after we boot the new cpu (and
consequently having to wait for it before enabling interrupts) set the
cpu active before we set it online and avoid the whole mess.

Reported-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1323965362.18942.71.camel@twins
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-12 20:43:15 +01:00
Linus Torvalds
4293f20c19 Revert "CPU hotplug, cpusets, suspend: Don't touch cpusets during suspend/resume"
This reverts commit 8f2f748b06.

It causes some odd regression that we have not figured out, and it's too
late in the -rc series to try to figure it out now.

As reported by Konstantin Khlebnikov, it causes consistent hangs on his
laptop (Thinkpad x220: 2x cores + HT).  They can be avoided by adding
calls to "rebuild_sched_domains();" in cpuset_cpu_[in]active() for the
CPU_{ONLINE/DOWN_FAILED/DOWN_PREPARE}_FROZEN cases, but it's not at all
clear why, and it makes no sense.

Konstantin's config doesn't even have CONFIG_CPUSETS enabled, just to
make things even more interesting.  So it's not the cpusets, it's just
the scheduling domains.

So until this is understood, revert.

Bisected-reported-and-tested-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-07 08:21:19 -08:00
Ingo Molnar
737f24bda7 Merge branch 'perf/urgent' into perf/core
Conflicts:
	tools/perf/builtin-record.c
	tools/perf/builtin-top.c
	tools/perf/perf.h
	tools/perf/util/top.h

Merge reason: resolve these cherry-picking conflicts.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-05 09:20:08 +01:00
Peter Zijlstra
367456c756 sched: Ditch per cgroup task lists for load-balancing
Per cgroup load-balance has numerous problems, chief amongst them that
there is no real sane order in them. So stop pretending it makes sense
and enqueue all tasks on a single list.

This also allows us to more easily fix the fwd progress issue
uncovered by the lock-break stuff. Rotate the list on failure to
migreate and limit the total iterations to nr_running (which with
releasing the lock isn't strictly accurate but close enough).

Also add a filter that skips very light tasks on the first attempt
around the list, this attempts to avoid shooting whole cgroups around
without affecting over balance.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: pjt@google.com
Link: http://lkml.kernel.org/n/tip-tx8yqydc7eimgq7i4rkc3a4g@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-01 13:08:37 +01:00
Thomas Gleixner
3c7d51843b sched/rt: Do not submit new work when PI-blocked
When we are PI-blocked then we want to get things done ASAP.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-vw8et3445km5b8mpihf4trae@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-01 10:46:54 +01:00
Thomas Gleixner
1c4dd99bed sched/rt: Prevent idle task boosting
Idle task boosting is a nono in general. There is one
exception, when PREEMPT_RT and NOHZ is active:

The idle task calls get_next_timer_interrupt() and holds
the timer wheel base->lock on the CPU and another CPU wants
to access the timer (probably to cancel it). We can safely
ignore the boosting request, as the idle CPU runs this code
with interrupts disabled and will complete the lock
protected section without being interrupted. So there is no
real need to boost.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-755rvsosz7sdzot12a3gbha6@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-01 10:28:05 +01:00
Thomas Gleixner
63b2001169 sched/wait: Add __wake_up_all_locked() API
For code which protects the waitqueue itself with another lock it
makes no sense to acquire the waitqueue lock for wakeup all. Provide
__wake_up_all_locked().

This is an optimization on the vanilla kernel (to be used by the
PCI code) and an important semantic distinction on -rt.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-ux6m4b8jonb9inx8xafh77ds@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-01 10:28:04 +01:00
Thomas Gleixner
ba74c1448f sched/rt: Document scheduler related skip-resched-check sites
Create a distinction between scheduler related preempt_enable_no_resched()
calls and the nearly one hundred other places in the kernel that do not
want to reschedule, for one reason or another.

This distinction matters for -rt, where the scheduler and the non-scheduler
preempt models (and checks) are different. For upstream it's purely
documentational.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/n/tip-gs88fvx2mdv5psnzxnv575ke@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-01 10:28:04 +01:00
Thomas Gleixner
c5491ea779 sched/rt: Add schedule_preempt_disabled()
Add helper to get rid of the ever repeating:

    preempt_enable_no_resched();
    schedule();
    preempt_disable();

patterns.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-wxx7btox7coby6ifv5vzhzgp@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-01 10:28:03 +01:00
Ingo Molnar
7e4d960993 Merge branch 'linus' into sched/core
Merge reason: we'll queue up dependent patches.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-01 10:26:43 +01:00
Srivatsa S. Bhat
8f2f748b06 CPU hotplug, cpusets, suspend: Don't touch cpusets during suspend/resume
Currently, during CPU hotplug, the cpuset callbacks modify the cpusets
to reflect the state of the system, and this handling is asymmetric.
That is, upon CPU offline, that CPU is removed from all cpusets. However
when it comes back online, it is put back only to the root cpuset.

This gives rise to a significant problem during suspend/resume. During
suspend, we offline all non-boot cpus and during resume we online them back.
Which means, after a resume, all cpusets (except the root cpuset) will be
restricted to just one single CPU (the boot cpu). But the whole point of
suspend/resume is to restore the system to a state which is as close as
possible to how it was before suspend.

So to fix this, don't touch cpusets during suspend/resume. That is, modify
the cpuset-related CPU hotplug callback to just ignore CPU hotplug when it
is initiated as part of the suspend/resume sequence.

Reported-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/4F460D7B.1020703@linux.vnet.ibm.com
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-27 11:38:13 +01:00
Ingo Molnar
c5905afb0e static keys: Introduce 'struct static_key', static_key_true()/false() and static_key_slow_[inc|dec]()
So here's a boot tested patch on top of Jason's series that does
all the cleanups I talked about and turns jump labels into a
more intuitive to use facility. It should also address the
various misconceptions and confusions that surround jump labels.

Typical usage scenarios:

        #include <linux/static_key.h>

        struct static_key key = STATIC_KEY_INIT_TRUE;

        if (static_key_false(&key))
                do unlikely code
        else
                do likely code

Or:

        if (static_key_true(&key))
                do likely code
        else
                do unlikely code

The static key is modified via:

        static_key_slow_inc(&key);
        ...
        static_key_slow_dec(&key);

The 'slow' prefix makes it abundantly clear that this is an
expensive operation.

I've updated all in-kernel code to use this everywhere. Note
that I (intentionally) have not pushed through the rename
blindly through to the lowest levels: the actual jump-label
patching arch facility should be named like that, so we want to
decouple jump labels from the static-key facility a bit.

On non-jump-label enabled architectures static keys default to
likely()/unlikely() branches.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jason Baron <jbaron@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: a.p.zijlstra@chello.nl
Cc: mathieu.desnoyers@efficios.com
Cc: davem@davemloft.net
Cc: ddaney.cavm@gmail.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20120222085809.GA26397@elte.hu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-24 10:05:59 +01:00
Peter Zijlstra
8c79a045fd sched/events: Revert trace_sched_stat_sleeptime()
Commit 1ac9bc69 ("sched/tracing: Add a new tracepoint for sleeptime")
added a new sched:sched_stat_sleeptime tracepoint.

It's broken: the first sample we get on a task might be bad because
of a stale sleep_start value that wasn't reset at the last task switch
because the tracepoint was not active.

It also breaks the existing schedstat samples due to the side
effects of:

-               se->statistics.sleep_start = 0;
...
-               se->statistics.block_start = 0;

Nor do I see means to fix it without adding overhead to the scheduler
fast path, which I'm not willing to for the sake of redundant
instrumentation.

Most importantly, sleep time information can already be constructed
by tracing context switches and wakeups, and taking the timestamp
difference between the schedule-out, the wakeup and the schedule-in.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/n/tip-pc4c9qhl8q6vg3bs4j6k0rbd@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-22 12:06:55 +01:00
Al Viro
4040153087 security: trim security.h
Trim security.h

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Morris <jmorris@namei.org>
2012-02-14 10:45:42 +11:00
Li Zefan
761b3ef50e cgroup: remove cgroup_subsys argument from callbacks
The argument is not used at all, and it's not necessary, because
a specific callback handler of course knows which subsys it
belongs to.

Now only ->pupulate() takes this argument, because the handlers of
this callback always call cgroup_add_file()/cgroup_add_files().

So we reduce a few lines of code, though the shrinking of object size
is minimal.

 16 files changed, 113 insertions(+), 162 deletions(-)

   text    data     bss     dec     hex filename
5486240  656987 7039960 13183187         c928d3 vmlinux.o.orig
5486170  656987 7039960 13183117         c9288d vmlinux.o

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2012-02-02 09:20:22 -08:00
Peter Zijlstra
39be350127 sched, block: Unify cache detection
The block layer has some code trying to determine if two CPUs share a
cache, the scheduler has a similar function. Expose the function used
by the scheduler and make the block layer use it, thereby removing the
block layers usage of CONFIG_SCHED* and topology bits.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Jens Axboe <axboe@kernel.dk>
Link: http://lkml.kernel.org/r/1327579450.2446.95.camel@twins
2012-01-27 13:28:48 +01:00
Christian Borntraeger
db7e527da4 sched/s390: Fix compile error in sched/core.c
Commit 029632fbb7 ("sched: Make
separate sched*.c translation units") removed the include of
asm/mutex.h from sched.c.

This breaks the combination of:

 CONFIG_MUTEX_SPIN_ON_OWNER=yes
 CONFIG_HAVE_ARCH_MUTEX_CPU_RELAX=yes

like s390 without mutex debugging:

  CC      kernel/sched/core.o
  kernel/sched/core.c: In function ‘mutex_spin_on_owner’:
  kernel/sched/core.c:3287: error: implicit declaration of function ‘arch_mutex_cpu_relax’

Lets re-add the include to kernel/sched/core.c

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1326268696-30904-1-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-26 19:38:11 +01:00
Peter Zijlstra
4ca9b72b71 sched: Fix rq->nr_uninterruptible update race
KOSAKI Motohiro noticed the following race:

 > CPU0                    CPU1
 > --------------------------------------------------------
 > deactivate_task()
 >                         task->state = TASK_UNINTERRUPTIBLE;
 > activate_task()
 >    rq->nr_uninterruptible--;
 >
 >                         schedule()
 >                           deactivate_task()
 >                             rq->nr_uninterruptible++;
 >

Kosaki-San's scenario is possible when CPU0 runs
__sched_setscheduler() against CPU1's current @task.

__sched_setscheduler() does a dequeue/enqueue in order to move
the task to its new queue (position) to reflect the newly provided
scheduling parameters. However it should be completely invariant to
nr_uninterruptible accounting, sched_setscheduler() doesn't affect
readyness to run, merely policy on when to run.

So convert the inappropriate activate/deactivate_task usage to
enqueue/dequeue_task, which avoids the nr_uninterruptible accounting.

Also convert the two other sites: __migrate_task() and
normalize_task() that still use activate/deactivate_task. These sites
aren't really a problem since __migrate_task() will only be called on
non-running task (and therefore are immume to the described problem)
and normalize_task() isn't ever used on regular systems.

Also remove the comments from activate/deactivate_task since they're
misleading at best.

Reported-by: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1327486224.2614.45.camel@laptop
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-26 19:38:09 +01:00
Linus Torvalds
c49c41a413 Merge branch 'for-linus' of git://selinuxproject.org/~jmorris/linux-security
* 'for-linus' of git://selinuxproject.org/~jmorris/linux-security:
  capabilities: remove __cap_full_set definition
  security: remove the security_netlink_recv hook as it is equivalent to capable()
  ptrace: do not audit capability check when outputing /proc/pid/stat
  capabilities: remove task_ns_* functions
  capabitlies: ns_capable can use the cap helpers rather than lsm call
  capabilities: style only - move capable below ns_capable
  capabilites: introduce new has_ns_capabilities_noaudit
  capabilities: call has_ns_capability from has_capability
  capabilities: remove all _real_ interfaces
  capabilities: introduce security_capable_noaudit
  capabilities: reverse arguments to security_capable
  capabilities: remove the task from capable LSM hook entirely
  selinux: sparse fix: fix several warnings in the security server cod
  selinux: sparse fix: fix warnings in netlink code
  selinux: sparse fix: eliminate warnings for selinuxfs
  selinux: sparse fix: declare selinux_disable() in security.h
  selinux: sparse fix: move selinux_complete_init
  selinux: sparse fix: make selinux_secmark_refcount static
  SELinux: Fix RCU deref check warning in sel_netport_insert()

Manually fix up a semantic mis-merge wrt security_netlink_recv():

 - the interface was removed in commit fd77846152 ("security: remove
   the security_netlink_recv hook as it is equivalent to capable()")

 - a new user of it appeared in commit a38f7907b9 ("crypto: Add
   userspace configuration API")

causing no automatic merge conflict, but Eric Paris pointed out the
issue.
2012-01-14 18:36:33 -08:00
Linus Torvalds
b8bf17d311 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix lockup by limiting load-balance retries on lock-break
  sched: Fix CONFIG_CGROUP_SCHED dependency
  sched: Remove empty #ifdefs
2012-01-11 22:52:48 -08:00
Hiroshi Shimamoto
9b9fb610f6 sched: Remove empty #ifdefs
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4F0B8525.8070901@ct.jp.nec.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-10 09:57:41 +01:00
Linus Torvalds
db0c2bf69a Merge branch 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
* 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits)
  cgroup: fix to allow mounting a hierarchy by name
  cgroup: move assignement out of condition in cgroup_attach_proc()
  cgroup: Remove task_lock() from cgroup_post_fork()
  cgroup: add sparse annotation to cgroup_iter_start() and cgroup_iter_end()
  cgroup: mark cgroup_rmdir_waitq and cgroup_attach_proc() as static
  cgroup: only need to check oldcgrp==newgrp once
  cgroup: remove redundant get/put of task struct
  cgroup: remove redundant get/put of old css_set from migrate
  cgroup: Remove unnecessary task_lock before fetching css_set on migration
  cgroup: Drop task_lock(parent) on cgroup_fork()
  cgroups: remove redundant get/put of css_set from css_set_check_fetched()
  resource cgroups: remove bogus cast
  cgroup: kill subsys->can_attach_task(), pre_attach() and attach_task()
  cgroup, cpuset: don't use ss->pre_attach()
  cgroup: don't use subsys->can_attach_task() or ->attach_task()
  cgroup: introduce cgroup_taskset and use it in subsys->can_attach(), cancel_attach() and attach()
  cgroup: improve old cgroup handling in cgroup_attach_proc()
  cgroup: always lock threadgroup during migration
  threadgroup: extend threadgroup_lock() to cover exit and exec
  threadgroup: rename signal->threadgroup_fork_lock to ->group_rwsem
  ...

Fix up conflict in kernel/cgroup.c due to commit e0197aae59: "cgroups:
fix a css_set not found bug in cgroup_attach_proc" that already
mentioned that the bug is fixed (differently) in Tejun's cgroup
patchset. This one, in other words.
2012-01-09 12:59:24 -08:00
Linus Torvalds
972b2c7199 Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (165 commits)
  reiserfs: Properly display mount options in /proc/mounts
  vfs: prevent remount read-only if pending removes
  vfs: count unlinked inodes
  vfs: protect remounting superblock read-only
  vfs: keep list of mounts for each superblock
  vfs: switch ->show_options() to struct dentry *
  vfs: switch ->show_path() to struct dentry *
  vfs: switch ->show_devname() to struct dentry *
  vfs: switch ->show_stats to struct dentry *
  switch security_path_chmod() to struct path *
  vfs: prefer ->dentry->d_sb to ->mnt->mnt_sb
  vfs: trim includes a bit
  switch mnt_namespace ->root to struct mount
  vfs: take /proc/*/mounts and friends to fs/proc_namespace.c
  vfs: opencode mntget() mnt_set_mountpoint()
  vfs: spread struct mount - remaining argument of next_mnt()
  vfs: move fsnotify junk to struct mount
  vfs: move mnt_devname
  vfs: move mnt_list to struct mount
  vfs: switch pnode.h macros to struct mount *
  ...
2012-01-08 12:19:57 -08:00
Linus Torvalds
7affca3537 Merge branch 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
* 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (73 commits)
  arm: fix up some samsung merge sysdev conversion problems
  firmware: Fix an oops on reading fw_priv->fw in sysfs loading file
  Drivers:hv: Fix a bug in vmbus_driver_unregister()
  driver core: remove __must_check from device_create_file
  debugfs: add missing #ifdef HAS_IOMEM
  arm: time.h: remove device.h #include
  driver-core: remove sysdev.h usage.
  clockevents: remove sysdev.h
  arm: convert sysdev_class to a regular subsystem
  arm: leds: convert sysdev_class to a regular subsystem
  kobject: remove kset_find_obj_hinted()
  m86k: gpio - convert sysdev_class to a regular subsystem
  mips: txx9_sram - convert sysdev_class to a regular subsystem
  mips: 7segled - convert sysdev_class to a regular subsystem
  sh: dma - convert sysdev_class to a regular subsystem
  sh: intc - convert sysdev_class to a regular subsystem
  power: suspend - convert sysdev_class to a regular subsystem
  power: qe_ic - convert sysdev_class to a regular subsystem
  power: cmm - convert sysdev_class to a regular subsystem
  s390: time - convert sysdev_class to a regular subsystem
  ...

Fix up conflicts with 'struct sysdev' removal from various platform
drivers that got changed:
 - arch/arm/mach-exynos/cpu.c
 - arch/arm/mach-exynos/irq-eint.c
 - arch/arm/mach-s3c64xx/common.c
 - arch/arm/mach-s3c64xx/cpu.c
 - arch/arm/mach-s5p64x0/cpu.c
 - arch/arm/mach-s5pv210/common.c
 - arch/arm/plat-samsung/include/plat/cpu.h
 - arch/powerpc/kernel/sysfs.c
and fix up cpu_is_hotpluggable() as per Greg in include/linux/cpu.h
2012-01-07 12:03:30 -08:00
Arun Sharma
1ac9bc6943 sched/tracing: Add a new tracepoint for sleeptime
If CONFIG_SCHEDSTATS is defined, the kernel maintains
information about how long the task was sleeping or
in the case of iowait, blocking in the kernel before
getting woken up.

This will be useful for sleep time profiling.

Note: this information is only provided for sched_fair.
Other scheduling classes may choose to provide this in
the future.

Note: the delay includes the time spent on the runqueue
as well.

Signed-off-by: Arun Sharma <asharma@fb.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1324512940-32060-2-git-send-email-asharma@fb.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-23 17:56:17 +01:00
Dave Jones
664dfa65e8 sched: Disable scheduler warnings during oopses
The panic-on-framebuffer code seems to cause a schedule
to occur during an oops. This causes a bunch of extra
spew as can be seen in:

   https://bugzilla.redhat.com/attachment.cgi?id=549230

Don't do scheduler debug checks when we are oopsing already.

Signed-off-by: Dave Jones <davej@redhat.com>
Link: http://lkml.kernel.org/r/20111222213929.GA4722@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-23 11:20:50 +01:00
Kamalesh Babulal
11534ec5b6 sched: Remove cfs bandwidth period check in tg_set_cfs_period()
Remove cfs bandwidth period check from tg_set_cfs_period.
Invalid bandwidth period's lower/upper limits are denoted
by min_cfs_quota_period/max_cfs_quota_period repsectively,
and are checked against valid period in tg_set_cfs_bandwidth().

As pjt pointed out, negative input will result in very large unsigned
numbers and will be caught by the max allowed period test.

Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Acked-by: Paul Turner <pjt@google.com>
[ammended changelog to mention negative values]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20111210135925.GA14593@linux.vnet.ibm.com
--
 kernel/sched/core.c |    3 ---
 1 file changed, 3 deletions(-)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:34:48 +01:00
Peter Zijlstra
518cd62341 sched: Only queue remote wakeups when crossing cache boundaries
Mike reported a 13% drop in netperf TCP_RR performance due to the
new remote wakeup code. Suresh too noticed some performance issues
with it.

Reducing the IPIs to only cross cache domains solves the observed
performance issues.

Reported-by: Suresh Siddha <suresh.b.siddha@intel.com>
Reported-by: Mike Galbraith <efault@gmx.de>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Dave Kleikamp <dave.kleikamp@oracle.com>
Link: http://lkml.kernel.org/r/1323338531.17673.7.camel@twins
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:34:44 +01:00
Martin Schwidefsky
612ef28a04 Merge branch 'sched/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into cputime-tip
Conflicts:
	drivers/cpufreq/cpufreq_conservative.c
	drivers/cpufreq/cpufreq_ondemand.c
	drivers/macintosh/rack-meter.c
	fs/proc/stat.c
	fs/proc/uptime.c
	kernel/sched/core.c
2011-12-19 19:23:15 +01:00
Kees Cook
07cde2608a sched: Add missing rcu_dereference() around ->real_parent usage
Wrap another ->real_parent dereference while under rcu_read_lock.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Link: http://lkml.kernel.org/r/20111215164918.GA13003@www.outflux.net
[ tidied up the changelog ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-16 09:42:09 +01:00
Peter Zijlstra
f8b6d1cc7d sched: Use jump_labels for sched_feat
Now that we initialize jump_labels before sched_init() we can use them
for the debug features without having to worry about a window where
they have the wrong setting.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-vpreo4hal9e0kzqmg5y0io2k@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 20:51:26 +01:00
Glauber Costa
be726ffd1e sched/accounting: Fix parameter passing in task_group_account_field
The order of parameters is inverted. The index parameter
should come first.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1322863119-14225-3-git-send-email-glommer@parallels.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 20:51:24 +01:00
Glauber Costa
1c77f38ad6 sched/accounting: Fix user/system tick double accounting
Now that we're  pointing cpuacct's root cgroup to cpustat and accounting
through task_group_account_field(), we should not access cpustat directly.
Since it is done anyway inside the acessor function, we end up accounting
it twice, which is wrong.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1322863119-14225-2-git-send-email-glommer@parallels.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 20:51:23 +01:00
Glauber Costa
54c707e98d sched/accounting: Re-use scheduler statistics for the root cgroup
Right now, after we collect tick statistics for user and system and store them
in a well known location, we keep the same statistics again for cpuacct.
Since cpuacct is hierarchical, the numbers for the root cgroup should be
absolutely equal to the system-wide numbers.

So it would be better to just use it: this patch changes cpuacct accounting
in a way that the cpustat statistics are kept in a struct kernel_cpustat percpu
array. In the root cgroup case, we just point it to the main array. The rest of
the hierarchy walk can be totally disabled later with a static branch - but I am
not doing it here.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Tuner <pjt@google.com>
Link: http://lkml.kernel.org/r/1322498719-2255-4-git-send-email-glommer@parallels.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 20:51:21 +01:00
Glauber Costa
44252e421a sched/accounting, cgroups: Reuse cgroup's parent pointer
We already have a pointer to the cgroup parent (whose data is more likely
to be in the cache than this, anyway), so there is no need to have this one
in cpuacct.

This patch makes the underlying cgroup be used instead.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Tuner <pjt@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1322498719-2255-3-git-send-email-glommer@parallels.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 09:06:40 +01:00
Glauber Costa
3292beb340 sched/accounting: Change cpustat fields to an array
This patch changes fields in cpustat from a structure, to an
u64 array. Math gets easier, and the code is more flexible.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Tuner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1322498719-2255-2-git-send-email-glommer@parallels.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 09:06:38 +01:00
Suresh Siddha
69e1e811dc sched, nohz: Track nr_busy_cpus in the sched_group_power
Introduce nr_busy_cpus in the struct sched_group_power [Not in sched_group
because sched groups are duplicated for the SD_OVERLAP scheduler domain]
and for each cpu that enters and exits idle, this parameter will
be updated in each scheduler group of the scheduler domain that this cpu
belongs to.

To avoid the frequent update of this state as the cpu enters
and exits idle, the update of the stat during idle exit is
delayed to the first timer tick that happens after the cpu becomes busy.
This is done using NOHZ_IDLE flag in the struct rq's nohz_flags.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20111202010832.555984323@sbsiddha-desk.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 09:06:32 +01:00
Suresh Siddha
1c792db7f7 sched, nohz: Introduce nohz_flags in 'struct rq'
Introduce nohz_flags in the struct rq, which will track these two flags
for now.

NOHZ_TICK_STOPPED keeps track of the tick stopped status that gets set when
the tick is stopped. It will be used to update the nohz idle load balancer data
structures during the first busy tick after the tick is restarted. At this
first busy tick after tickless idle, NOHZ_TICK_STOPPED flag will be reset.
This will minimize the nohz idle load balancer status updates that currently
happen for every tickless exit, making it more scalable when there
are many logical cpu's that enter and exit idle often.

NOHZ_BALANCE_KICK will track the need for nohz idle load balance
on this rq. This will replace the nohz_balance_kick in the rq, which was
not being updated atomically.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20111202010832.499438999@sbsiddha-desk.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 09:06:30 +01:00
Suresh Siddha
4d78a2239e sched: Fix the sched group node allocation for SD_OVERLAP domains
For the SD_OVERLAP domain, sched_groups for each CPU's sched_domain are
privately allocated and not shared with any other cpu. So the
sched group allocation should come from the cpu's node for which
SD_OVERLAP sched domain is being setup.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20111118230554.164910950@sbsiddha-desk.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 09:06:26 +01:00
Mike Galbraith
916671c08b sched: Set skip_clock_update in yield_task_fair()
This is another case where we are on our way to schedule(),
so can save a useless clock update and resulting microscopic
vruntime update.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1321971686.6855.18.camel@marge.simson.net
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 09:06:24 +01:00
Peter Zijlstra
391e43da79 sched: Move all scheduler bits into kernel/sched/
There's too many sched*.[ch] files in kernel/, give them their own
directory.

(No code changed, other than Makefile glue added.)

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-17 12:20:22 +01:00