From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Date: Thu, 16 Apr 2015 19:48:04 +0000 (-0700)
Subject: cpumask: don't perform while loop in cpumask_next_and()
X-Git-Tag: firefly_0821_release~176^2~1948^2~33
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=534b483a86e6b96f1b5cc03bbe4b696f3daead6d;p=firefly-linux-kernel-4.4.55.git

cpumask: don't perform while loop in cpumask_next_and()

cpumask_next_and() is looking for cpumask_next() in src1 in a loop and
tests if found cpu is also present in src2. remove that loop, perform
cpumask_and() of src1 and src2 first and use that new mask to find
cpumask_next().

Apart from removing while loop, ./bloat-o-meter on x86_64 shows
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-8 (-8)
function                                     old     new   delta
cpumask_next_and                              62      54      -8

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Amir Vadai <amirv@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/lib/cpumask.c b/lib/cpumask.c
index b6513a9f2892..5ab1553fd076 100644
--- a/lib/cpumask.c
+++ b/lib/cpumask.c
@@ -37,10 +37,11 @@ EXPORT_SYMBOL(__next_cpu_nr);
 int cpumask_next_and(int n, const struct cpumask *src1p,
 		     const struct cpumask *src2p)
 {
-	while ((n = cpumask_next(n, src1p)) < nr_cpu_ids)
-		if (cpumask_test_cpu(n, src2p))
-			break;
-	return n;
+	struct cpumask tmp;
+
+	if (cpumask_and(&tmp, src1p, src2p))
+		return cpumask_next(n, &tmp);
+	return nr_cpu_ids;
 }
 EXPORT_SYMBOL(cpumask_next_and);