cpumask: don't perform while loop in cpumask_next_and()
authorSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Thu, 16 Apr 2015 19:48:04 +0000 (12:48 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 17 Apr 2015 13:04:08 +0000 (09:04 -0400)
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

index b6513a9f2892042a8a49a5bc872c0ca33990e2d8..5ab1553fd07633c3b729a8501ce89238f37174f5 100644 (file)
@@ -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);