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authorJason Low <jason.low2@hp.com>2015-04-28 13:00:24 -0700
committerIngo Molnar <mingo@kernel.org>2015-05-08 12:17:46 +0200
commit7110744516276e906f9197e2857d026eb2343393 (patch)
treee9add9fbd4c901ed5b004e630370df515c6f1210 /kernel/time/posix-cpu-timers.c
parent971e8a985482c76487edb5a49811e99b96e846e1 (diff)
sched, timer: Use the atomic task_cputime in thread_group_cputimer
Recent optimizations were made to thread_group_cputimer to improve its scalability by keeping track of cputime stats without a lock. However, the values were open coded to the structure, causing them to be at a different abstraction level from the regular task_cputime structure. Furthermore, any subsequent similar optimizations would not be able to share the new code, since they are specific to thread_group_cputimer. This patch adds the new task_cputime_atomic data structure (introduced in the previous patch in the series) to thread_group_cputimer for keeping track of the cputime atomically, which also helps generalize the code. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Jason Low <jason.low2@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Waiman Long <Waiman.Long@hp.com> Link: http://lkml.kernel.org/r/1430251224-5764-6-git-send-email-jason.low2@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/time/posix-cpu-timers.c')
-rw-r--r--kernel/time/posix-cpu-timers.c26
1 files changed, 13 insertions, 13 deletions
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index d85730669410..892e3dae0aac 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -211,20 +211,20 @@ retry:
}
}
-static void update_gt_cputime(struct thread_group_cputimer *cputimer, struct task_cputime *sum)
+static void update_gt_cputime(struct task_cputime_atomic *cputime_atomic, struct task_cputime *sum)
{
- __update_gt_cputime(&cputimer->utime, sum->utime);
- __update_gt_cputime(&cputimer->stime, sum->stime);
- __update_gt_cputime(&cputimer->sum_exec_runtime, sum->sum_exec_runtime);
+ __update_gt_cputime(&cputime_atomic->utime, sum->utime);
+ __update_gt_cputime(&cputime_atomic->stime, sum->stime);
+ __update_gt_cputime(&cputime_atomic->sum_exec_runtime, sum->sum_exec_runtime);
}
-/* Sample thread_group_cputimer values in "cputimer", store results in "times". */
-static inline void sample_group_cputimer(struct task_cputime *times,
- struct thread_group_cputimer *cputimer)
+/* Sample task_cputime_atomic values in "atomic_timers", store results in "times". */
+static inline void sample_cputime_atomic(struct task_cputime *times,
+ struct task_cputime_atomic *atomic_times)
{
- times->utime = atomic64_read(&cputimer->utime);
- times->stime = atomic64_read(&cputimer->stime);
- times->sum_exec_runtime = atomic64_read(&cputimer->sum_exec_runtime);
+ times->utime = atomic64_read(&atomic_times->utime);
+ times->stime = atomic64_read(&atomic_times->stime);
+ times->sum_exec_runtime = atomic64_read(&atomic_times->sum_exec_runtime);
}
void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
@@ -240,7 +240,7 @@ void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
* to synchronize the timer to the clock every time we start it.
*/
thread_group_cputime(tsk, &sum);
- update_gt_cputime(cputimer, &sum);
+ update_gt_cputime(&cputimer->cputime_atomic, &sum);
/*
* We're setting cputimer->running without a lock. Ensure
@@ -251,7 +251,7 @@ void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
*/
WRITE_ONCE(cputimer->running, 1);
}
- sample_group_cputimer(times, cputimer);
+ sample_cputime_atomic(times, &cputimer->cputime_atomic);
}
/*
@@ -1137,7 +1137,7 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
if (READ_ONCE(sig->cputimer.running)) {
struct task_cputime group_sample;
- sample_group_cputimer(&group_sample, &sig->cputimer);
+ sample_cputime_atomic(&group_sample, &sig->cputimer.cputime_atomic);
if (task_cputime_expired(&group_sample, &sig->cputime_expires))
return 1;