Commit Graph

56 Commits

Author SHA1 Message Date
David Vrabel
8785c67663 xen/x86: set VIRQ_TIMER priority to maximum
Commit bee980d9e (xen/events: Handle VIRQ_TIMER before any other hardirq
in event loop) effectively made the VIRQ_TIMER the highest priority event
when using the 2-level ABI.

Set the VIRQ_TIMER priority to the highest so this behaviour is retained
when using the FIFO-based ABI.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2014-01-06 10:07:55 -05:00
Michael Opdenacker
9d71cee667 x86/xen: remove deprecated IRQF_DISABLED
This patch proposes to remove the IRQF_DISABLED flag from x86/xen
code. It's a NOOP since 2.6.35 and it will be removed one day.

Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-11-06 15:31:01 -05:00
Linus Torvalds
21884a83b2 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer core updates from Thomas Gleixner:
 "The timer changes contain:

   - posix timer code consolidation and fixes for odd corner cases

   - sched_clock implementation moved from ARM to core code to avoid
     duplication by other architectures

   - alarm timer updates

   - clocksource and clockevents unregistration facilities

   - clocksource/events support for new hardware

   - precise nanoseconds RTC readout (Xen feature)

   - generic support for Xen suspend/resume oddities

   - the usual lot of fixes and cleanups all over the place

  The parts which touch other areas (ARM/XEN) have been coordinated with
  the relevant maintainers.  Though this results in an handful of
  trivial to solve merge conflicts, which we preferred over nasty cross
  tree merge dependencies.

  The patches which have been committed in the last few days are bug
  fixes plus the posix timer lot.  The latter was in akpms queue and
  next for quite some time; they just got forgotten and Frederic
  collected them last minute."

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (59 commits)
  hrtimer: Remove unused variable
  hrtimers: Move SMP function call to thread context
  clocksource: Reselect clocksource when watchdog validated high-res capability
  posix-cpu-timers: don't account cpu timer after stopped thread runtime accounting
  posix_timers: fix racy timer delta caching on task exit
  posix-timers: correctly get dying task time sample in posix_cpu_timer_schedule()
  selftests: add basic posix timers selftests
  posix_cpu_timers: consolidate expired timers check
  posix_cpu_timers: consolidate timer list cleanups
  posix_cpu_timer: consolidate expiry time type
  tick: Sanitize broadcast control logic
  tick: Prevent uncontrolled switch to oneshot mode
  tick: Make oneshot broadcast robust vs. CPU offlining
  x86: xen: Sync the CMOS RTC as well as the Xen wallclock
  x86: xen: Sync the wallclock when the system time is set
  timekeeping: Indicate that clock was set in the pvclock gtod notifier
  timekeeping: Pass flags instead of multiple bools to timekeeping_update()
  xen: Remove clock_was_set() call in the resume path
  hrtimers: Support resuming with two or more CPUs online (but stopped)
  timer: Fix jiffies wrap behavior of round_jiffies_common()
  ...
2013-07-06 14:09:38 -07:00
David Vrabel
47433b8c9d x86: xen: Sync the CMOS RTC as well as the Xen wallclock
Adjustments to Xen's persistent clock via update_persistent_clock()
don't actually persist, as the Xen wallclock is a software only clock
and modifications to it do not modify the underlying CMOS RTC.

The x86_platform.set_wallclock hook is there to keep the hardware RTC
synchronized. On a guest this is pointless.

On Dom0 we can use the native implementaion which actually updates the
hardware RTC, but we still need to keep the software emulation of RTC
for the guests up to date. The subscription to the pvclock_notifier
allows us to emulate this easily. The notifier is called at every tick
and when the clock was set.

Right now we only use that notifier when the clock was set, but due to
the fact that it is called periodically from the timekeeping update
code, we can utilize it to emulate the NTP driven drift compensation
of update_persistant_clock() for the Xen wall (software) clock.

Add a 11 minutes periodic update to the pvclock_gtod notifier callback
to achieve that. The static variable 'next' which maintains that 11
minutes update cycle is protected by the core code serialization so
there is no need to add a Xen specific serialization mechanism.

[ tglx: Massaged changelog and added a few comments ]

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/1372329348-20841-6-git-send-email-david.vrabel@citrix.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-06-28 23:15:07 +02:00
David Vrabel
5584880e44 x86: xen: Sync the wallclock when the system time is set
Currently the Xen wallclock is only updated every 11 minutes if NTP is
synchronized to its clock source (using the sync_cmos_clock() work).
If a guest is started before NTP is synchronized it may see an
incorrect wallclock time.

Use the pvclock_gtod notifier chain to receive a notification when the
system time has changed and update the wallclock to match.

This chain is called on every timer tick and we want to avoid an extra
(expensive) hypercall on every tick.  Because dom0 has historically
never provided a very accurate wallclock and guests do not expect one,
we can do this simply: the wallclock is only updated if the clock was
set.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/1372329348-20841-5-git-send-email-david.vrabel@citrix.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-06-28 23:15:06 +02:00
Laszlo Ersek
0b0c002c34 xen/time: remove blocked time accounting from xen "clockchip"
... because the "clock_event_device framework" already accounts for idle
time through the "event_handler" function pointer in
xen_timer_interrupt().

The patch is intended as the completion of [1]. It should fix the double
idle times seen in PV guests' /proc/stat [2]. It should be orthogonal to
stolen time accounting (the removed code seems to be isolated).

The approach may be completely misguided.

[1] https://lkml.org/lkml/2011/10/6/10
[2] http://lists.xensource.com/archives/html/xen-devel/2010-08/msg01068.html

John took the time to retest this patch on top of v3.10 and reported:
"idle time is correctly incremented for pv and hvm for the normal
case, nohz=off and nohz=idle." so lets put this patch in.

CC: stable@vger.kernel.org
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: John Haxby <john.haxby@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-06-28 12:11:39 -04:00
Konrad Rzeszutek Wilk
09e99da766 xen/time: Free onlined per-cpu data structure if we want to online it again.
If the per-cpu time data structure has been onlined already and
we are trying to online it again, then free the previous copy
before blindly over-writting it.

A developer naturally should not call this function multiple times
but just in case.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-06-10 08:43:37 -04:00
Konrad Rzeszutek Wilk
a05e2c371f xen/time: Check that the per_cpu data structure has data before freeing.
We don't check whether the per_cpu data structure has actually
been freed in the past. This checks it and if it has been freed
in the past then just continues on without double-freeing.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-06-10 08:43:36 -04:00
Konrad Rzeszutek Wilk
c9d76a24a2 xen/time: Don't leak interrupt name when offlining.
When the user does:
    echo 0 > /sys/devices/system/cpu/cpu1/online
    echo 1 > /sys/devices/system/cpu/cpu1/online

kmemleak reports:
kmemleak: 7 new suspected memory leaks (see /sys/kernel/debug/kmemleak)

One of the leaks is from xen/time:

unreferenced object 0xffff88003fa51280 (size 32):
  comm "swapper/0", pid 1, jiffies 4294667339 (age 1027.789s)
  hex dump (first 32 bytes):
    74 69 6d 65 72 31 00 00 00 00 00 00 00 00 00 00  timer1..........
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff81660721>] kmemleak_alloc+0x21/0x50
    [<ffffffff81190aac>] __kmalloc_track_caller+0xec/0x2a0
    [<ffffffff812fe1bb>] kvasprintf+0x5b/0x90
    [<ffffffff812fe228>] kasprintf+0x38/0x40
    [<ffffffff81041ec1>] xen_setup_timer+0x51/0xf0
    [<ffffffff8166339f>] xen_cpu_up+0x5f/0x3e8
    [<ffffffff8166bbf5>] _cpu_up+0xd1/0x14b
    [<ffffffff8166bd48>] cpu_up+0xd9/0xec
    [<ffffffff81ae6e4a>] smp_init+0x4b/0xa3
    [<ffffffff81ac4981>] kernel_init_freeable+0xdb/0x1e6
    [<ffffffff8165ce39>] kernel_init+0x9/0xf0
    [<ffffffff8167edfc>] ret_from_fork+0x7c/0xb0
    [<ffffffffffffffff>] 0xffffffffffffffff

This patch fixes it by stashing away the 'name' in the per-cpu
data structure and freeing it when offlining the CPU.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-06-10 08:43:35 -04:00
Konrad Rzeszutek Wilk
31620a198c xen/time: Encapsulate the struct clock_event_device in another structure.
We don't do any code movement. We just encapsulate the struct clock_event_device
in a new structure which contains said structure and a pointer to
a char *name. The 'name' will be used in 'xen/time: Don't leak interrupt
name when offlining'.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-06-10 08:43:34 -04:00
David Vrabel
3565184ed0 x86: Increase precision of x86_platform.get/set_wallclock()
All the virtualized platforms (KVM, lguest and Xen) have persistent
wallclocks that have more than one second of precision.

read_persistent_wallclock() and update_persistent_wallclock() allow
for nanosecond precision but their implementation on x86 with
x86_platform.get/set_wallclock() only allows for one second precision.
This means guests may see a wallclock time that is off by up to 1
second.

Make set_wallclock() and get_wallclock() take a struct timespec
parameter (which allows for nanosecond precision) so KVM and Xen
guests may start with a more accurate wallclock time and a Xen dom0
can maintain a more accurate wallclock for guests.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-05-28 14:00:59 -07:00
Konrad Rzeszutek Wilk
ef35a4e6d9 xen/time: Add default value of -1 for IRQ and check for that.
If the timer interrupt has been de-init or is just now being
initialized, the default value of -1 should be preset as
interrupt line. Check for that and if something is odd
WARN us.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-04-16 16:05:14 -04:00
Konrad Rzeszutek Wilk
7918c92ae9 xen/time: Fix kasprintf splat when allocating timer%d IRQ line.
When we online the CPU, we get this splat:

smpboot: Booting Node 0 Processor 1 APIC 0x2
installing Xen timer for CPU 1
BUG: sleeping function called from invalid context at /home/konrad/ssd/konrad/linux/mm/slab.c:3179
in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1
Pid: 0, comm: swapper/1 Not tainted 3.9.0-rc6upstream-00001-g3884fad #1
Call Trace:
 [<ffffffff810c1fea>] __might_sleep+0xda/0x100
 [<ffffffff81194617>] __kmalloc_track_caller+0x1e7/0x2c0
 [<ffffffff81303758>] ? kasprintf+0x38/0x40
 [<ffffffff813036eb>] kvasprintf+0x5b/0x90
 [<ffffffff81303758>] kasprintf+0x38/0x40
 [<ffffffff81044510>] xen_setup_timer+0x30/0xb0
 [<ffffffff810445af>] xen_hvm_setup_cpu_clockevents+0x1f/0x30
 [<ffffffff81666d0a>] start_secondary+0x19c/0x1a8

The solution to that is use kasprintf in the CPU hotplug path
that 'online's the CPU. That is, do it in in xen_hvm_cpu_notify,
and remove the call to in xen_hvm_setup_cpu_clockevents.

Unfortunatly the later is not a good idea as the bootup path
does not use xen_hvm_cpu_notify so we would end up never allocating
timer%d interrupt lines when booting. As such add the check for
atomic() to continue.

CC: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-04-16 16:05:07 -04:00
Linus Torvalds
403299a851 Merge branch 'upstream/xen-settime' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen
* 'upstream/xen-settime' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen/dom0: set wallclock time in Xen
  xen: add dom0_op hypercall
  xen/acpi: Domain0 acpi parser related platform hypercall
2011-11-06 20:15:05 -08:00
Jeremy Fitzhardinge
fdb9eb9f15 xen/dom0: set wallclock time in Xen
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-09-26 11:04:39 -07:00
Jeremy Fitzhardinge
f1c39625d6 xen: use non-tracing preempt in xen_clocksource_read()
The tracing code used sched_clock() to get tracing timestamps, which
ends up calling xen_clocksource_read().  xen_clocksource_read() must
disable preemption, but if preemption tracing is enabled, this results
in infinite recursion.

I've only noticed this when boot-time tracing tests are enabled, but it
seems like a generic bug.  It looks like it would also affect
kvm_clocksource_read().

Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
2011-08-24 09:54:24 -07:00
Linus Torvalds
0f1bdc1815 Merge branch 'timers-clocksource-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-clocksource-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  clocksource: convert mips to generic i8253 clocksource
  clocksource: convert x86 to generic i8253 clocksource
  clocksource: convert footbridge to generic i8253 clocksource
  clocksource: add common i8253 PIT clocksource
  blackfin: convert to clocksource_register_hz
  mips: convert to clocksource_register_hz/khz
  sparc: convert to clocksource_register_hz/khz
  alpha: convert to clocksource_register_hz
  microblaze: convert to clocksource_register_hz/khz
  ia64: convert to clocksource_register_hz/khz
  x86: Convert remaining x86 clocksources to clocksource_register_hz/khz
  Make clocksource name const
2011-05-19 17:44:13 -07:00
Daniel Kiper
fb6ce5dea4 arch/x86/xen/time: Cleanup code/data sections definitions
Cleanup code/data sections definitions
accordingly to include/linux/init.h.

Signed-off-by: Daniel Kiper <dkiper@net-space.pl>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-19 11:30:39 -04:00
Thomas Gleixner
a18f22a968 Merge branch 'consolidate-clksrc-i8253' of master.kernel.org:~rmk/linux-2.6-arm into timers/clocksource
Conflicts:
	arch/ia64/kernel/cyclone.c
	arch/mips/kernel/i8253.c
	arch/x86/kernel/i8253.c

Reason: Resolve conflicts so further cleanups do not conflict further

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-05-14 12:06:36 +02:00
Ian Campbell
f611f2da99 xen/timer: Missing IRQF_NO_SUSPEND in timer code broke suspend.
The patches missed an indirect use of IRQF_NO_SUSPEND pulled in via
IRQF_TIMER. The following patch fixes the issue.

With this fixlet PV guest migration works just fine. I also booted the
entire series as a dom0 kernel and it appeared fine.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-03 12:00:31 -05:00
John Stultz
b01cc1b0ea x86: Convert remaining x86 clocksources to clocksource_register_hz/khz
This converts the remaining x86 clocksources to use
clocksource_register_hz/khz.

CC: jacob.jun.pan@intel.com
CC: Glauber Costa <glommer@redhat.com>
CC: Dimitri Sivanich <sivanich@sgi.com>
CC: Rusty Russell <rusty@rustcorp.com.au>
CC: Jeremy Fitzhardinge <jeremy@xensource.com>
CC: Chris McDermott <lcm@us.ibm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [xen]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
2011-02-21 13:33:33 -08:00
Tejun Heo
275c8b9328 Merge branch 'this_cpu_ops' into for-2.6.38 2010-12-17 15:16:46 +01:00
Christoph Lameter
780f36d8b3 xen: Use this_cpu_ops
Use this_cpu_ops to reduce code size and simplify things in various places.

V3->V4:
	Move instance of this_cpu_inc_return to a later patchset so that
	this patch can be applied without infrastructure changes.

Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-17 15:07:19 +01:00
Jeremy Fitzhardinge
e7a3481c02 x86/pvclock: Zero last_value on resume
If the guest domain has been suspend/resumed or migrated, then the
system clock backing the pvclock clocksource may revert to a smaller
value (ie, can be non-monotonic across the migration/save-restore).

Make sure we zero last_value in that case so that the domain
continues to see clock updates.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-28 09:33:20 +01:00
Stefano Stabellini
31e7e931cd xen: do not initialize PV timers on HVM if !xen_have_vector_callback
if !xen_have_vector_callback do not initialize PV timer unconditionally
because we still don't know how many cpus are available and if there is
more than one we won't be able to receive the timer interrupts on
cpu > 0.

This patch fixes an hang at boot when Xen does not support vector
callbacks and the guest has multiple vcpus.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
2010-10-05 13:39:23 +01:00
Jeremy Fitzhardinge
ca50a5f390 Merge branch 'upstream/pvhvm' into upstream/xen
* upstream/pvhvm:
  Introduce CONFIG_XEN_PVHVM compile option
  blkfront: do not create a PV cdrom device if xen_hvm_guest
  support multiple .discard.* sections to avoid section type conflicts
  xen/pvhvm: fix build problem when !CONFIG_XEN
  xenfs: enable for HVM domains too
  x86: Call HVMOP_pagetable_dying on exit_mmap.
  x86: Unplug emulated disks and nics.
  x86: Use xen_vcpuop_clockevent, xen_clocksource and xen wallclock.
  xen: Fix find_unbound_irq in presence of ioapic irqs.
  xen: Add suspend/resume support for PV on HVM guests.
  xen: Xen PCI platform device driver.
  x86/xen: event channels delivery on HVM.
  x86: early PV on HVM features initialization.
  xen: Add support for HVM hypercalls.

Conflicts:
	arch/x86/xen/enlighten.c
	arch/x86/xen/time.c
2010-08-04 14:49:16 -07:00
Jeremy Fitzhardinge
a70ce4b606 Merge branch 'upstream/core' into upstream/xen
* upstream/core:
  xen/panic: use xen_reboot and fix smp_send_stop
  Xen: register panic notifier to take crashes of xen guests on panic
  xen: support large numbers of CPUs with vcpu info placement
  xen: drop xen_sched_clock in favour of using plain wallclock time
  pvops: do not notify callers from register_xenstore_notifier
  xen: make sure pages are really part of domain before freeing
  xen: release unused free memory
2010-08-04 14:49:05 -07:00
Jeremy Fitzhardinge
8a22b9996b xen: drop xen_sched_clock in favour of using plain wallclock time
xen_sched_clock only counts unstolen time.  In principle this should
be useful to the Linux scheduler so that it knows how much time a process
actually consumed.  But in practice this doesn't work very well as the
scheduler expects the sched_clock time to be synchronized between
cpus.  It also uses sched_clock to measure the time a task spends
sleeping, in which case "unstolen time" isn't meaningful.

So just use plain xen_clocksource_read to return wallclock nanoseconds
for sched_clock.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-08-04 14:47:29 -07:00
Stefano Stabellini
ca65f9fc0c Introduce CONFIG_XEN_PVHVM compile option
This patch introduce a CONFIG_XEN_PVHVM compile time option to
enable/disable Xen PV on HVM support.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2010-07-29 11:11:33 -07:00
Stefano Stabellini
409771d258 x86: Use xen_vcpuop_clockevent, xen_clocksource and xen wallclock.
Use xen_vcpuop_clockevent instead of hpet and APIC timers as main
clockevent device on all vcpus, use the xen wallclock time as wallclock
instead of rtc and use xen_clocksource as clocksource.
The pv clock algorithm needs to work correctly for the xen_clocksource
and xen wallclock to be usable, only modern Xen versions offer a
reliable pv clock in HVM guests (XENFEAT_hvm_safe_pvclock).

Using the hpet as clocksource means a VMEXIT every time we read/write to
the hpet mmio addresses, pvclock give us a better rating without
VMEXITs. Same goes for the xen wallclock and xen_vcpuop_clockevent

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Don Dutile <ddutile@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-26 23:13:25 -07:00
Linus Torvalds
7d02093e29 Merge branch 'timers-for-linus-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-for-linus-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  avr32: Fix typo in read_persistent_clock()
  sparc: Convert sparc to use read/update_persistent_clock
  cris: Convert cris to use read/update_persistent_clock
  m68k: Convert m68k to use read/update_persistent_clock
  m32r: Convert m32r to use read/update_peristent_clock
  blackfin: Convert blackfin to use read/update_persistent_clock
  ia64: Convert ia64 to use read/update_persistent_clock
  avr32: Convert avr32 to use read/update_persistent_clock
  h8300: Convert h8300 to use read/update_persistent_clock
  frv: Convert frv to use read/update_persistent_clock
  mn10300: Convert mn10300 to use read/update_persistent_clock
  alpha: Convert alpha to use read/update_persistent_clock
  xtensa: Fix unnecessary setting of xtime
  time: Clean up direct xtime usage in xen
2010-05-19 17:10:06 -07:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
John Stultz
c450725776 time: Clean up direct xtime usage in xen
Cleanup xen's direct use of internal timekeeping values.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Acked-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-03-13 00:36:37 +01:00
Linus Torvalds
d0316554d3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (34 commits)
  m68k: rename global variable vmalloc_end to m68k_vmalloc_end
  percpu: add missing per_cpu_ptr_to_phys() definition for UP
  percpu: Fix kdump failure if booted with percpu_alloc=page
  percpu: make misc percpu symbols unique
  percpu: make percpu symbols in ia64 unique
  percpu: make percpu symbols in powerpc unique
  percpu: make percpu symbols in x86 unique
  percpu: make percpu symbols in xen unique
  percpu: make percpu symbols in cpufreq unique
  percpu: make percpu symbols in oprofile unique
  percpu: make percpu symbols in tracer unique
  percpu: make percpu symbols under kernel/ and mm/ unique
  percpu: remove some sparse warnings
  percpu: make alloc_percpu() handle array types
  vmalloc: fix use of non-existent percpu variable in put_cpu_var()
  this_cpu: Use this_cpu_xx in trace_functions_graph.c
  this_cpu: Use this_cpu_xx for ftrace
  this_cpu: Use this_cpu_xx in nmi handling
  this_cpu: Use this_cpu operations in RCU
  this_cpu: Use this_cpu ops for VM statistics
  ...

Fix up trivial (famous last words) global per-cpu naming conflicts in
	arch/x86/kvm/svm.c
	mm/slab.c
2009-12-14 09:58:24 -08:00
Ian Campbell
f350c7922f xen: register timer interrupt with IRQF_TIMER
Otherwise the timer is disabled by dpm_suspend_noirq() which in turn prevents
correct operation of stop_machine on multi-processor systems and breaks
suspend.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
2009-12-03 11:14:52 -08:00
Ian Campbell
be012920ec xen: re-register runstate area earlier on resume.
This is necessary to ensure the runstate area is available to
xen_sched_clock before any calls to printk which will require it in
order to provide a timestamp.

I chose to pull the xen_setup_runstate_info out of xen_time_init into
the caller in order to maintain parity with calling
xen_setup_runstate_info separately from calling xen_time_resume.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
2009-12-03 11:14:50 -08:00
Tejun Heo
c6e22f9e3e percpu: make percpu symbols in xen unique
This patch updates percpu related symbols in xen such that percpu
symbols are unique and don't clash with local symbols.  This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.

* arch/x86/xen/smp.c, arch/x86/xen/time.c, arch/ia64/xen/irq_xen.c:
  add xen_ prefix to percpu variables

* arch/ia64/xen/time.c: add xen_ prefix to percpu variables, drop
  processed_ prefix and make them static

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
2009-10-29 22:34:13 +09:00
Magnus Damm
8e19608e8b clocksource: pass clocksource to read() callback
Pass clocksource pointer to the read() callback for clocksources.  This
allows us to share the callback between multiple instances.

[hugh@veritas.com: fix powerpc build of clocksource pass clocksource mods]
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-21 13:41:47 -07:00
Linus Torvalds
61420f59a5 Merge branch 'cputime' of git://git390.osdl.marist.edu/pub/scm/linux-2.6
* 'cputime' of git://git390.osdl.marist.edu/pub/scm/linux-2.6:
  [PATCH] fast vdso implementation for CLOCK_THREAD_CPUTIME_ID
  [PATCH] improve idle cputime accounting
  [PATCH] improve precision of idle time detection.
  [PATCH] improve precision of process accounting.
  [PATCH] idle cputime accounting
  [PATCH] fix scaled & unscaled cputime accounting
2009-01-03 11:56:24 -08:00
Martin Schwidefsky
79741dd357 [PATCH] idle cputime accounting
The cpu time spent by the idle process actually doing something is
currently accounted as idle time. This is plain wrong, the architectures
that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the
time spent doing nothing and the time spent by idle doing work. The first
is accounted with account_idle_time and the second with account_system_time.
The architectures that use the account_xxx_time interface directly and not
the account_xxx_ticks interface now need to do the check for the idle
process in their arch code. In particular to improve the system vs true
idle time accounting the arch code needs to measure the true idle time
instead of just testing for the idle process.
To improve the tick based accounting as well we would need an architecture
primitive that can tell us if the pt_regs of the interrupted context
points to the magic instruction that halts the cpu.

In addition idle time is no more added to the stime of the idle process.
This field now contains the system time of the idle process as it should
be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as
every tick that occurs while idle is running will be accounted as idle
time.

This patch contains the necessary common code changes to be able to
distinguish idle system time and true idle time. The architectures with
support for VIRT_CPU_ACCOUNTING need some changes to exploit this.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 15:11:46 +01:00
Rusty Russell
320ab2b0b1 cpumask: convert struct clock_event_device to cpumask pointers.
Impact: change calling convention of existing clock_event APIs

struct clock_event_timer's cpumask field gets changed to take pointer,
as does the ->broadcast function.

Another single-patch change.  For safety, we BUG_ON() in
clockevents_register_device() if it's not set.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
2008-12-13 21:20:26 +10:30
Glauber Costa
3807f345b2 x86: paravirt: factor out cpu_khz to common code
KVM intends to use paravirt code to calibrate khz. Xen
current code will do just fine. So as a first step, factor out
code to pvclock.c.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:17 +02:00
Alex Nixon
d68d82afd4 xen: implement CPU hotplugging
Note the changes from 2.6.18-xen CPU hotplugging:

A vcpu_down request from the remote admin via Xenbus both hotunplugs the
CPU, and disables it by removing it from the cpu_present map, and removing
its entry in /sys.

A vcpu_up request from the remote admin only re-enables the CPU, and does
not immediately bring the CPU up. A udev event is emitted, which can be
caught by the user if he wishes to automatically re-up CPUs when available,
or implement a more complex policy.

Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-25 11:25:14 +02:00
Jeremy Fitzhardinge
ee7686bc04 x86: build fix in "xen spinlock updates and performance measurements"
Ingo Molnar wrote:
> -tip testing found this build failure:
>
>  arch/x86/xen/spinlock.c: In function ‘spin_time_start’:
>  arch/x86/xen/spinlock.c:60: error: implicit declaration of function ‘xen_clocksource_read’
>
> i've excluded these new commits for now from tip/master - could you
> please send a delta fix against tip/x86/xen?

Make xen_clocksource_read non-static.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-22 08:08:46 +02:00
Alok Kataria
e93ef949fd x86: rename paravirtualized TSC functions
Rename the paravirtualized calculate_cpu_khz to calibrate_tsc.
In all cases, we actually calibrate_tsc and use that as the cpu_khz value.

Signed-off-by: Alok N Kataria <akataria@vmware.com>
Signed-off-by: Dan Hecht <dhecht@vmware.com>
Cc: Dan Hecht <dhecht@vmware.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09 07:43:28 +02:00
Ingo Molnar
d02859ecb3 Merge commit 'v2.6.26-rc8' into x86/xen
Conflicts:

	arch/x86/xen/enlighten.c
	arch/x86/xen/mmu.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-25 12:16:51 +02:00
Gerd Hoffmann
1c7b67f757 x86: Make xen use the paravirt clocksource structs and functions
This patch updates the xen guest to use the pvclock structs
and helper functions.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24 21:02:32 +03:00
Ingo Molnar
688d22e23a Merge branch 'linus' into x86/xen 2008-06-16 11:21:27 +02:00
Jeremy Fitzhardinge
f595ec964d common implementation of iterative div/mod
We have a few instances of the open-coded iterative div/mod loop, used
when we don't expcet the dividend to be much bigger than the divisor.
Unfortunately modern gcc's have the tendency to strength "reduce" this
into a full mod operation, which isn't necessarily any faster, and
even if it were, doesn't exist if gcc implements it in libgcc.

The workaround is to put a dummy asm statement in the loop to prevent
gcc from performing the transformation.

This patch creates a single implementation of this loop, and uses it
to replace the open-coded versions I know about.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Christian Kujau <lists@nerdbynature.de>
Cc: Robert Hancock <hancockr@shaw.ca>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-12 10:47:56 +02:00
Jeremy Fitzhardinge
d07af1f0e3 xen: resume timers on all vcpus
On resume, the vcpu timer modes will not be restored.  The timer
infrastructure doesn't do this for us, since it assumes the cpus
are offline.  We can just poke the other vcpus into the right mode
directly though.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-02 13:25:44 +02:00