linux-toradex.git/kernel/posix-cpu-timers.c, branch v2.6.31

posix_cpu_timers_exit_group(): Do not use thread_group_cputimer()

2009-08-08T16:30:25+00:00

When the process exits we don't have to run new cputimer nor
use running one (as it not accounts when tsk->exit_state != 0)
to get process CPU times.  As there is only one thread we can
just use CPU times fields from task and signal structs.

Signed-off-by: Stanislaw Gruszka 
Cc: Peter Zijlstra 
Cc: Roland McGrath 
Cc: Vitaly Mayatskikh 
Signed-off-by: Andrew Morton 
Signed-off-by: Ingo Molnar

kernel/posix-cpu-timers.c: fix sparse warning

2009-04-30T06:08:31+00:00

Sparse reports the following in kernel/posix-cpu-timers.c:

  warning: symbol 'firing' shadows an earlier one

Signed-off-by: H Hartley Sweeten 
Cc: Subrata Modak 
LKML-Reference: 
Signed-off-by: Ingo Molnar

Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-04-09T17:37:28+00:00

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: do not count frozen tasks toward load
  sched: refresh MAINTAINERS entry
  sched: Print sched_group::__cpu_power in sched_domain_debug
  cpuacct: add per-cgroup utime/stime statistics
  posixtimers, sched: Fix posix clock monotonicity
  sched_rt: don't allocate cpumask in fastpath
  cpuacct: make cpuacct hierarchy walk in cpuacct_charge() safe when rcupreempt is used -v2

posix-timers: fix RLIMIT_CPU && setitimer(CPUCLOCK_PROF)

2009-04-08T15:51:39+00:00

update_rlimit_cpu() tries to optimize out set_process_cpu_timer() in case
when we already have CPUCLOCK_PROF timer which should expire first. But it
uses cputime_lt() instead of cputime_gt().

Test case:

	int main(void)
	{
		struct itimerval it = {
			.it_value = { .tv_sec = 1000 },
		};

		assert(!setitimer(ITIMER_PROF, &it, NULL));

		struct rlimit rl = {
			.rlim_cur = 1,
			.rlim_max = 1,
		};

		assert(!setrlimit(RLIMIT_CPU, &rl));

		for (;;)
			;

		return 0;
	}

Without this patch, the task is not killed as RLIMIT_CPU demands.

Signed-off-by: Oleg Nesterov 
Acked-by: Peter Zijlstra 
Cc: Peter Lojkin 
Cc: Roland McGrath 
Cc: stable@kernel.org
LKML-Reference: <20090327000610.GA10108@redhat.com>
Signed-off-by: Ingo Molnar

Merge commit 'v2.6.30-rc1' into sched/urgent

2009-04-08T15:26:00+00:00

Merge reason: update to latest upstream to queue up fix

Signed-off-by: Ingo Molnar

posixtimers, sched: Fix posix clock monotonicity

2009-04-01T14:44:16+00:00

Impact: Regression fix (against clock_gettime() backwarding bug)

This patch re-introduces a couple of functions, task_sched_runtime
and thread_group_sched_runtime, which was once removed at the
time of 2.6.28-rc1.

These functions protect the sampling of thread/process clock with
rq lock.  This rq lock is required not to update rq->clock during
the sampling.

i.e.
  The clock_gettime() may return
   ((accounted runtime before update) + (delta after update))
  that is less than what it should be.

v2 -> v3:
	- Rename static helper function __task_delta_exec()
	  to do_task_delta_exec() since -tip tree already has
	  a __task_delta_exec() of different version.

v1 -> v2:
	- Revises comments of function and patch description.
	- Add note about accuracy of thread group's runtime.

Signed-off-by: Hidetoshi Seto 
Acked-by: Peter Zijlstra 
Cc: stable@kernel.org	[2.6.28.x][2.6.29.x]
LKML-Reference: <49D1CC93.4080401@jp.fujitsu.com>
Signed-off-by: Ingo Molnar

posix timers: fix RLIMIT_CPU && fork()

2009-03-23T19:43:35+00:00

See http://bugzilla.kernel.org/show_bug.cgi?id=12911

copy_signal() copies signal->rlim, but RLIMIT_CPU is "lost". Because
posix_cpu_timers_init_group() sets cputime_expires.prof_exp = 0 and thus
fastpath_timer_check() returns false unless we have other cpu timers.

This is the minimal fix for 2.6.29 (tested) and 2.6.28. The patch is not
optimal, we need further cleanups here. With this patch update_rlimit_cpu()
is not really needed, but I don't think it should be removed.

The proper fix (I think) is:

	- set_process_cpu_timer() should just start the cputimer->running
	  logic (it does), no need to change cputime_expires.xxx_exp

	- posix_cpu_timers_init_group() should set ->running when needed

	- fastpath_timer_check() can check ->running instead of
	  task_cputime_zero(signal->cputime_expires)

Reported-by: Peter Lojkin 
Signed-off-by: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Roland McGrath 
Cc:  [for 2.6.29.x]
LKML-Reference: <20090323193411.GA17514@redhat.com>
Signed-off-by: Ingo Molnar

timers: more consistently use clock vs timer

2009-02-13T12:04:05+00:00

While reviewing the manpages, I noticed I'd missed some clock vs timer sites.

Make sure that all timer functions call cpu_timer_sample_group() and not
cpu_clock_sample_group(). This ensures that we enable the process wide timer
in time, and therefore pay the O(n) thread group cost from the syscall.

Not doing it here, will result in the first jiffy tick after setting the timer
doing this, resulting in a very expensive tick (but only once) and a delay in
actually starting the timer.

Signed-off-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar

timers: fix TIMER_ABSTIME for process wide cpu timers

2009-02-11T13:04:21+00:00

The POSIX timer interface allows for absolute time expiry values through the
TIMER_ABSTIME flag, therefore we have to synchronize the timer to the clock
every time we start it.

Signed-off-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar

timers: split process wide cpu clocks/timers, fix

2009-02-11T13:04:19+00:00

To decrease the chance of a missed enable, always enable the timer when we
sample it, we'll always disable it when we find that there are no active timers
in the jiffy tick.

This fixes a flood of warnings reported by Mike Galbraith.

Reported-by: Mike Galbraith 
Signed-off-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar