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	Original line	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		* userspace. Once a task gets some ticks, the monotonicy code at
	* 'update' will ensure things converge to the observed ratio.		* 'update' will ensure things converge to the observed ratio.
	*/		*/
	if (stime == 0) {		if (stime != 0) {
	utime = rtime;		if (utime == 0)
	goto update;
	}

	if (utime == 0) {
	stime = rtime;		stime = rtime;
	goto update;		else
	}

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

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

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