Commit 08e4570a authored Nov 26, 2007 by Ingo Molnar

sched: fix prev_stime calculation



Srivatsa Vaddagiri noticed occasionally incorrect CPU usage
values in top and tracked it down to stime going below 0 in
task_stime(). Negative values are possible there due to the
sampled nature of stime/utime.

Fix suggested by Balbir Singh.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com>

parent 5e8869bb

fs/proc/array.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -374,7 +374,9 @@ static cputime_t task_stime(struct task_struct *p)
		stime = nsec_to_clock_t(p->se.sum_exec_runtime) -
		cputime_to_clock_t(task_utime(p));

		if (stime >= 0)
		p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime));

		return p->prev_stime;
		}
		#endif

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