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| author | Thomas Gleixner <tglx@linutronix.de> | 2014-07-16 21:04:34 +0000 |
|---|---|---|
| committer | John Stultz <john.stultz@linaro.org> | 2014-07-23 10:18:05 -0700 |
| commit | ccbf62d8a284cf181ac28c8e8407dd077d90dd4b (patch) | |
| tree | 7e1a4fffdc9a8f46e4bd22ad6070ad4fa768f1ed /kernel | |
| parent | 57e0be041d9e21a7397eed3b67a7936ac4ac83c0 (diff) | |
| download | linux-ccbf62d8a284cf181ac28c8e8407dd077d90dd4b.tar.gz linux-ccbf62d8a284cf181ac28c8e8407dd077d90dd4b.tar.bz2 linux-ccbf62d8a284cf181ac28c8e8407dd077d90dd4b.zip | |
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')
| -rw-r--r-- | kernel/acct.c | 10 | ||||
| -rw-r--r-- | kernel/fork.c | 2 | ||||
| -rw-r--r-- | kernel/tsacct.c | 19 |
3 files changed, 13 insertions, 18 deletions
diff --git a/kernel/acct.c b/kernel/acct.c index 1be013c6053e..a1844f14c6d6 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -458,9 +458,7 @@ static void do_acct_process(struct bsd_acct_struct *acct, acct_t ac; mm_segment_t fs; unsigned long flim; - u64 elapsed; - u64 run_time; - struct timespec uptime; + u64 elapsed, run_time; struct tty_struct *tty; const struct cred *orig_cred; @@ -484,10 +482,8 @@ static void do_acct_process(struct bsd_acct_struct *acct, strlcpy(ac.ac_comm, current->comm, sizeof(ac.ac_comm)); /* calculate run_time in nsec*/ - ktime_get_ts(&uptime); - run_time = (u64)uptime.tv_sec*NSEC_PER_SEC + uptime.tv_nsec; - run_time -= (u64)current->group_leader->start_time.tv_sec * NSEC_PER_SEC - + current->group_leader->start_time.tv_nsec; + run_time = ktime_get_ns(); + run_time -= current->group_leader->start_time; /* convert nsec -> AHZ */ elapsed = nsec_to_AHZ(run_time); #if ACCT_VERSION==3 diff --git a/kernel/fork.c b/kernel/fork.c index a7ab82db2f60..627b7f80afb0 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1262,7 +1262,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, posix_cpu_timers_init(p); - ktime_get_ts(&p->start_time); + p->start_time = ktime_get_ns(); p->real_start_time = ktime_get_boot_ns(); p->io_context = NULL; p->audit_context = NULL; 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) |