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posix-cpu-timers: Provide array based sample functions 

Instead of using task_cputime and doing the addition of utime and stime at
all call sites, it's way simpler to have a sample array which allows
indexed based checks against the expiry cache array.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192921.590362974@linutronix.de
This commit is contained in:
Thomas Gleixner 2019-08-21 21:09:12 +02:00
parent bbc9bae1e4
commit b0d524f779
1 changed files with 26 additions and 0 deletions
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26
kernel/time/posix-cpu-timers.c
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@ -202,6 +202,32 @@ static u64 cpu_clock_sample(const clockid_t clkid, struct task_struct *p)
return 0;
}
static inline void store_samples(u64 *samples, u64 stime, u64 utime, u64 rtime)
{
samples[CPUCLOCK_PROF] = stime + utime;
samples[CPUCLOCK_VIRT] = utime;
samples[CPUCLOCK_SCHED] = rtime;
}
static void task_sample_cputime(struct task_struct *p, u64 *samples)
{
u64 stime, utime;
task_cputime(p, &utime, &stime);
store_samples(samples, stime, utime, p->se.sum_exec_runtime);
}
static void proc_sample_cputime_atomic(struct task_cputime_atomic *at,
u64 *samples)
{
u64 stime, utime, rtime;
utime = atomic64_read(&at->utime);
stime = atomic64_read(&at->stime);
rtime = atomic64_read(&at->sum_exec_runtime);
store_samples(samples, stime, utime, rtime);
}
/*
* Set cputime to sum_cputime if sum_cputime > cputime. Use cmpxchg
* to avoid race conditions with concurrent updates to cputime.