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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2007-10-29 21:18:11 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2007-10-29 21:18:11 +0100 |
| commit | 73a2bcb0edb9ffb0b007b3546b430e2c6e415eee (patch) | |
| tree | dd84f61589c7dd21b7be973c288611ffe547f21b | |
| parent | f7402e0361d4472535e07cfca648f2fa81d85cd2 (diff) | |
| download | linux-73a2bcb0edb9ffb0b007b3546b430e2c6e415eee.tar.bz2 | |
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: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | fs/proc/array.c | 3 | ||||
| -rw-r--r-- | include/linux/sched.h | 1 | ||||
| -rw-r--r-- | kernel/fork.c | 1 |
3 files changed, 4 insertions, 1 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c index 63c95afb561f..d80baaabf835 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -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) diff --git a/include/linux/sched.h b/include/linux/sched.h index 3c07d595979f..b0b1fe6e0b17 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -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 */ diff --git a/kernel/fork.c b/kernel/fork.c index ddafdfac9456..a65bfc47177c 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -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 */ |