From 534b483a86e6b96f1b5cc03bbe4b696f3daead6d Mon Sep 17 00:00:00 2001
From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Date: Thu, 16 Apr 2015 12:48:04 -0700
Subject: [PATCH] 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>
---
lib/cpumask.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
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);
--
2.20.1