Commit 73a2bcb0 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar

sched: keep utime/stime monotonic

keep utime/stime monotonic.

cpustats use utime/stime as a ratio against sum_exec_runtime, as a
consequence it can happen - when the ratio changes faster than time
accumulates - that either can be appear to go backwards.
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent f7402e03
......@@ -358,7 +358,8 @@ static cputime_t task_utime(struct task_struct *p)
}
utime = (clock_t)temp;
return clock_t_to_cputime(utime);
p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime));
return p->prev_utime;
}
static cputime_t task_stime(struct task_struct *p)
......
......@@ -1009,6 +1009,7 @@ struct task_struct {
unsigned int rt_priority;
cputime_t utime, stime, utimescaled, stimescaled;
cputime_t gtime;
cputime_t prev_utime;
unsigned long nvcsw, nivcsw; /* context switch counts */
struct timespec start_time; /* monotonic time */
struct timespec real_start_time; /* boot based time */
......
......@@ -1056,6 +1056,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->gtime = cputime_zero;
p->utimescaled = cputime_zero;
p->stimescaled = cputime_zero;
p->prev_utime = cputime_zero;
#ifdef CONFIG_TASK_XACCT
p->rchar = 0; /* I/O counter: bytes read */
......
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