Commit 72298e5c authored Jun 29, 2017 by Gustavo A. R. Silva Committed by Ingo Molnar Jun 30, 2017

sched/cputime: Refactor the cputime_adjust() code



Address a Coverity false positive, which is caused by overly
convoluted code:

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
Signed-off-by: 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: Peter Zijlstra <peterz@infradead.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>
Link: http://lkml.kernel.org/r/20170629184128.GA5271@embeddedgus


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 48365b38

kernel/sched/cputime.c

+5 −11

Original line number	Diff line number	Diff line
		@@ -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 (utime == 0) {
		if (stime != 0) {
		if (utime == 0)
		stime = rtime;
		goto update;
		}

		else
		stime = scale_stime(stime, rtime, stime + utime);
		}

		update:
		/*
		* Make sure stime doesn't go backwards; this preserves monotonicity
		* for utime because rtime is monotonic.