diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2014-07-17 01:04:34 +0400 |
|---|---|---|
| committer | John Stultz <john.stultz@linaro.org> | 2014-07-23 21:18:05 +0400 |
| commit | ccbf62d8a284cf181ac28c8e8407dd077d90dd4b (patch) | |
| tree | 7e1a4fffdc9a8f46e4bd22ad6070ad4fa768f1ed /kernel/tsacct.c | |
| parent | 57e0be041d9e21a7397eed3b67a7936ac4ac83c0 (diff) | |
| download | linux-ccbf62d8a284cf181ac28c8e8407dd077d90dd4b.tar.xz | |
sched: Make task->start_time nanoseconds based
Simplify the timespec to nsec/usec conversions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Diffstat (limited to 'kernel/tsacct.c')
| -rw-r--r-- | kernel/tsacct.c | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/kernel/tsacct.c b/kernel/tsacct.c index ea6d170452c4..975cb49e32bf 100644 --- a/kernel/tsacct.c +++ b/kernel/tsacct.c @@ -31,20 +31,19 @@ void bacct_add_tsk(struct user_namespace *user_ns, struct taskstats *stats, struct task_struct *tsk) { const struct cred *tcred; - struct timespec uptime, ts; cputime_t utime, stime, utimescaled, stimescaled; - u64 ac_etime; + u64 delta; BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN); - /* calculate task elapsed time in timespec */ - ktime_get_ts(&uptime); - ts = timespec_sub(uptime, tsk->start_time); - /* rebase elapsed time to usec (should never be negative) */ - ac_etime = timespec_to_ns(&ts); - do_div(ac_etime, NSEC_PER_USEC); - stats->ac_etime = ac_etime; - stats->ac_btime = get_seconds() - ts.tv_sec; + /* calculate task elapsed time in nsec */ + delta = ktime_get_ns() - tsk->start_time; + /* Convert to micro seconds */ + do_div(delta, NSEC_PER_USEC); + stats->ac_etime = delta; + /* Convert to seconds for btime */ + do_div(delta, USEC_PER_SEC); + stats->ac_btime = get_seconds() - delta; if (thread_group_leader(tsk)) { stats->ac_exitcode = tsk->exit_code; if (tsk->flags & PF_FORKNOEXEC) |