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| author | Ingo Molnar <mingo@kernel.org> | 2017-07-04 11:53:40 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-07-04 11:58:05 +0200 |
| commit | 3b9c08ae3dd44201b3a188aef34d6ddf73434015 (patch) | |
| tree | e2c36ee566d82c3e170abac710f4af0b966f9e50 /kernel/sched/cputime.c | |
| parent | 4422d80ed7d4bdb2d6e9fb890c66c3d9250ba694 (diff) | |
| download | linux-3b9c08ae3dd44201b3a188aef34d6ddf73434015.tar.bz2 | |
Revert "sched/cputime: Refactor the cputime_adjust() code"
This reverts commit 72298e5c92c50edd8cb7cfda4519483ce65fa166.
As Peter explains:
> Argh, no... That code was perfectly fine. The new code otoh is
> convoluted.
>
> The old code had the following form:
>
> if (exception1)
> deal with exception1
>
> if (execption2)
> deal with exception2
>
> do normal stuff
>
> Which is as simple and straight forward as it gets.
>
> The new code otoh reads like:
>
> if (!exception1) {
> if (exception2)
> deal with exception 2
> else
> do normal stuff
> }
So restore the old form.
Also fix the comment describing the logic, as it was confusing.
Requested-by: Peter Zijlstra <peterz@infradead.org>
Cc: Gustavo A. R. Silva <garsilva@embeddedor.com>
Cc: Frans Klaver <fransklaver@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/cputime.c')
| -rw-r--r-- | kernel/sched/cputime.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 67c70e287647..84a419bdf5aa 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -611,17 +611,23 @@ static void cputime_adjust(struct task_cputime *curr, utime = curr->utime; /* - * If either stime or both stime and utime are 0, assume all runtime is - * userspace. Once a task gets some ticks, the monotonicy code at - * 'update' will ensure things converge to the observed ratio. + * If either stime or utime are 0, assume all runtime is userspace. + * Once a task gets some ticks, the monotonicy code at 'update:' + * will ensure things converge to the observed ratio. */ - if (stime != 0) { - if (utime == 0) - stime = rtime; - else - stime = scale_stime(stime, rtime, stime + utime); + if (stime == 0) { + utime = rtime; + goto update; } + if (utime == 0) { + stime = rtime; + goto update; + } + + stime = scale_stime(stime, rtime, stime + utime); + +update: /* * Make sure stime doesn't go backwards; this preserves monotonicity * for utime because rtime is monotonic. |