linux.git/kernel, branch v3.12-rc3

Merge branches 'sched-urgent-for-linus', 'timers-urgent-for-linus' and 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2013-09-28T21:22:17+00:00

Pull scheduler, timer and x86 fixes from Ingo Molnar:
 - A context tracking ARM build and functional fix
 - A handful of ARM clocksource/clockevent driver fixes
 - An AMD microcode patch level sysfs reporting fixlet

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arm: Fix build error with context tracking calls

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: em_sti: Set cpu_possible_mask to fix SMP broadcast
  clocksource: of: Respect device tree node status
  clocksource: exynos_mct: Set IRQ affinity when the CPU goes online
  arm: clocksource: mvebu: Use the main timer as clock source from DT

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/microcode/AMD: Fix patch level reporting for family 15h

kernel/params: fix handling of signed integer types

2013-09-28T19:35:52+00:00

Commit 6072ddc8520b ("kernel: replace strict_strto*() with kstrto*()")
broke the handling of signed integer types, fix it.

Signed-off-by: Jean Delvare 
Reported-by: Christian Kujau 
Tested-by: Christian Kujau 
Cc: Jingoo Han 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'context_tracking/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into sched/urgent

2013-09-28T06:50:09+00:00

Pull context tracking ARM fix from Frederic Weisbecker.

Signed-off-by: Ingo Molnar

arm: Fix build error with context tracking calls

2013-09-27T15:59:47+00:00

ad65782fba50 (context_tracking: Optimize main APIs off case
with static key) converted context tracking main APIs to inline
function and left ARM asm callers behind.

This can be easily fixed by making ARM calling the post static
keys context tracking function. We just need to replicate the
static key checks there. We'll remove these later when ARM will
support the context tracking static keys.

Reported-by: Guenter Roeck 
Reported-by: Russell King 
Signed-off-by: Frederic Weisbecker 
Tested-by: Kevin Hilman 
Cc: Nicolas Pitre 
Cc: Anil Kumar 
Cc: Tony Lindgren 
Cc: Benoit Cousson 
Cc: Guenter Roeck 
Cc: Russell King 
Cc: Kevin Hilman

Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2013-09-25T20:28:45+00:00

Pull scheduler fixes from Ingo Molnar:
 "Three small fixes"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/balancing: Fix cfs_rq->task_h_load calculation
  sched/balancing: Fix 'local->avg_load > busiest->avg_load' case in fix_small_imbalance()
  sched/balancing: Fix 'local->avg_load > sds->avg_load' case in calculate_imbalance()

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2013-09-25T20:28:08+00:00

Pull perf fixes from Ingo Molnar:
 "Assorted standalone fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Add model number for Avoton Silvermont
  perf: Fix capabilities bitfield compatibility in 'struct perf_event_mmap_page'
  perf/x86/intel/uncore: Don't use smp_processor_id() in validate_group()
  perf: Update ABI comment
  tools lib lk: Uninclude linux/magic.h in debugfs.c
  perf tools: Fix old GCC build error in trace-event-parse.c:parse_proc_kallsyms()
  perf probe: Fix finder to find lines of given function
  perf session: Check for SIGINT in more loops
  perf tools: Fix compile with libelf without get_phdrnum
  perf tools: Fix buildid cache handling of kallsyms with kcore
  perf annotate: Fix objdump line parsing offset validation
  perf tools: Fill in new definitions for madvise()/mmap() flags
  perf tools: Sharpen the libaudit dependencies test

kernel/reboot.c: re-enable the function of variable reboot_default

2013-09-25T00:00:26+00:00

Commit 1b3a5d02ee07 ("reboot: move arch/x86 reboot= handling to generic
kernel") did some cleanup for reboot= command line, but it made the
reboot_default inoperative.

The default value of variable reboot_default should be 1, and if command
line reboot= is not set, system will use the default reboot mode.

[akpm@linux-foundation.org: fix comment layout]
Signed-off-by: Li Fei 
Signed-off-by: liu chuansheng 
Acked-by: Robin Holt 
Cc: 	[3.11.x]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

audit: fix endless wait in audit_log_start()

2013-09-25T00:00:26+00:00

After commit 829199197a43 ("kernel/audit.c: avoid negative sleep
durations") audit emitters will block forever if userspace daemon cannot
handle backlog.

After the timeout the waiting loop turns into busy loop and runs until
daemon dies or returns back to work.  This is a minimal patch for that
bug.

Signed-off-by: Konstantin Khlebnikov 
Cc: Luiz Capitulino 
Cc: Richard Guy Briggs 
Cc: Eric Paris 
Cc: Chuck Anderson 
Cc: Dan Duval 
Cc: Dave Kleikamp 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

watchdog: update watchdog_thresh properly

2013-09-25T00:00:25+00:00

watchdog_tresh controls how often nmi perf event counter checks per-cpu
hrtimer_interrupts counter and blows up if the counter hasn't changed
since the last check.  The counter is updated by per-cpu
watchdog_hrtimer hrtimer which is scheduled with 2/5 watchdog_thresh
period which guarantees that hrtimer is scheduled 2 times per the main
period.  Both hrtimer and perf event are started together when the
watchdog is enabled.

So far so good.  But...

But what happens when watchdog_thresh is updated from sysctl handler?

proc_dowatchdog will set a new sampling period and hrtimer callback
(watchdog_timer_fn) will use the new value in the next round.  The
problem, however, is that nobody tells the perf event that the sampling
period has changed so it is ticking with the period configured when it
has been set up.

This might result in an ear ripping dissonance between perf and hrtimer
parts if the watchdog_thresh is increased.  And even worse it might lead
to KABOOM if the watchdog is configured to panic on such a spurious
lockup.

This patch fixes the issue by updating both nmi perf even counter and
hrtimers if the threshold value has changed.

The nmi one is disabled and then reinitialized from scratch.  This has
an unpleasant side effect that the allocation of the new event might
fail theoretically so the hard lockup detector would be disabled for
such cpus.  On the other hand such a memory allocation failure is very
unlikely because the original event is deallocated right before.

It would be much nicer if we just changed perf event period but there
doesn't seem to be any API to do that right now.  It is also unfortunate
that perf_event_alloc uses GFP_KERNEL allocation unconditionally so we
cannot use on_each_cpu() and do the same thing from the per-cpu context.
The update from the current CPU should be safe because
perf_event_disable removes the event atomically before it clears the
per-cpu watchdog_ev so it cannot change anything under running handler
feet.

The hrtimer is simply restarted (thanks to Don Zickus who has pointed
this out) if it is queued because we cannot rely it will fire&adopt to
the new sampling period before a new nmi event triggers (when the
treshold is decreased).

[akpm@linux-foundation.org: the UP version of __smp_call_function_single ended up in the wrong place]
Signed-off-by: Michal Hocko 
Acked-by: Don Zickus 
Cc: Frederic Weisbecker 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Fabio Estevam 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

watchdog: update watchdog attributes atomically

2013-09-25T00:00:25+00:00

proc_dowatchdog doesn't synchronize multiple callers which might lead to
confusion when two parallel callers might confuse watchdog_enable_all_cpus
resp watchdog_disable_all_cpus (eg watchdog gets enabled even if
watchdog_thresh was set to 0 already).

This patch adds a local mutex which synchronizes callers to the sysctl
handler.

Signed-off-by: Michal Hocko 
Cc: Frederic Weisbecker 
Acked-by: Don Zickus 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds