diff options
| author | Frans Pop <elendil@planet.nl> | 2007-11-14 01:18:19 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-11-16 08:12:44 -0800 |
| commit | e823c33c6f670beba3c14f4a451fd2b34c3eb40c (patch) | |
| tree | fae5671652e463b861e3737524caab6d992adcf6 /fs | |
| parent | 436e61d93605a3a36902c9ee510b0ecba0d7d361 (diff) | |
sched: keep utime/stime monotonic
sched: 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.
Combined backport for 2.6.23 of the following patches from mainline:
commit 73a2bcb0edb9ffb0b007b3546b430e2c6e415eee
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
sched: keep utime/stime monotonic
commit 9301899be75b464ef097f0b5af7af6d9bd8f68a7
Author: Balbir Singh <balbir@linux.vnet.ibm.com>
sched: fix /proc/<PID>/stat stime/utime monotonicity, part 2
Signed-off-by: Frans Pop <elendil@planet.nl>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/proc/array.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c index ee4814dd98f9..20d7ae4582e2 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -351,7 +351,8 @@ 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) @@ -366,7 +367,8 @@ 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)); - return clock_t_to_cputime(stime); + p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime)); + return p->prev_stime; } #endif |