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Commit b0d524f7 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

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: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192921.590362974@linutronix.de
parent bbc9bae1

kernel/time/posix-cpu-timers.c

+26 −0
Original line number Diff line number Diff line
@@ -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.