linux-kernel - [PATCH] sched/cputime: code refactoring in cputime

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Date:   Thu, 29 Jun 2017 13:41:28 -0500
From:   "Gustavo A. R. Silva" <garsilva@...eddedor.com>
To:     Frans Klaver <fransklaver@...il.com>,
        Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>
Cc:     linux-kernel@...r.kernel.org
Subject: [PATCH] sched/cputime: code refactoring in cputime_adjust()

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@...il.com>
Signed-off-by: Gustavo A. R. Silva <garsilva@...eddedor.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