From: "Gustavo A. R. Silva" <garsilva@embeddedor.com>
To: Frans Klaver <fransklaver@gmail.com>,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH] sched/cputime: code refactoring in cputime_adjust()
Date: Thu, 29 Jun 2017 13:41:28 -0500 [thread overview]
Message-ID: <20170629184128.GA5271@embeddedgus> (raw)
In-Reply-To: <20170629125804.Horde.gm62Mi9SrTXYOk8B_t9Srrr@gator4166.hostgator.com>
Value assigned to variable utime at line 619:utime = rtime;
is overwritten at line 642:utime = rtime - stime; before it
can be used. This makes such variable assignment useless.
Remove this variable assignment and refactor the code related.
Addresses-Coverity-ID: 1371643
Cc: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
---
kernel/sched/cputime.c | 16 +++++-----------
1 file changed, 5 insertions(+), 11 deletions(-)
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index aea3135..a83fd9a 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -615,19 +615,13 @@ static void cputime_adjust(struct task_cputime *curr,
* userspace. Once a task gets some ticks, the monotonicy code at
* 'update' will ensure things converge to the observed ratio.
*/
- if (stime == 0) {
- utime = rtime;
- goto update;
+ if (stime != 0) {
+ if (utime == 0)
+ stime = rtime;
+ else
+ stime = scale_stime(stime, rtime, stime + utime);
}
- 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.
--
2.5.0
next prev parent reply other threads:[~2017-06-29 18:41 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-27 23:03 [kernel-sched-cputime] question about probable bug in cputime_adjust() Gustavo A. R. Silva
2017-06-28 5:35 ` Frans Klaver
2017-06-28 6:03 ` Frans Klaver
2017-06-28 23:57 ` Gustavo A. R. Silva
2017-06-29 4:51 ` Frans Klaver
2017-06-29 17:58 ` Gustavo A. R. Silva
2017-06-29 18:41 ` Gustavo A. R. Silva [this message]
2017-06-30 13:10 ` [tip:sched/core] sched/cputime: Refactor the cputime_adjust() code tip-bot for Gustavo A. R. Silva
2017-06-30 14:00 ` Rik van Riel
2017-06-30 14:41 ` Frans Klaver
2017-06-30 15:46 ` Frederic Weisbecker
2017-06-30 16:17 ` Stanislaw Gruszka
2017-07-04 9:17 ` Peter Zijlstra
2017-07-04 10:01 ` Ingo Molnar
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