From 1a36e59d4833de19120dc7482c61ef69e228c73c Mon Sep 17 00:00:00 2001 From: Sha Zhengju Date: Thu, 12 Sep 2013 15:13:49 -0700 Subject: [PATCH] memcg: reduce function dereference This function dereferences res far too often, so optimize it. Signed-off-by: Sha Zhengju Signed-off-by: Qiang Huang Acked-by: Michal Hocko Cc: Daisuke Nishimura Cc: Jeff Liu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/res_counter.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/kernel/res_counter.c b/kernel/res_counter.c index 085d3ae478fe..4aa8a305aede 100644 --- a/kernel/res_counter.c +++ b/kernel/res_counter.c @@ -178,27 +178,30 @@ u64 res_counter_read_u64(struct res_counter *counter, int member) #endif int res_counter_memparse_write_strategy(const char *buf, - unsigned long long *res) + unsigned long long *resp) { char *end; + unsigned long long res; /* return RES_COUNTER_MAX(unlimited) if "-1" is specified */ if (*buf == '-') { - *res = simple_strtoull(buf + 1, &end, 10); - if (*res != 1 || *end != '\0') + res = simple_strtoull(buf + 1, &end, 10); + if (res != 1 || *end != '\0') return -EINVAL; - *res = RES_COUNTER_MAX; + *resp = RES_COUNTER_MAX; return 0; } - *res = memparse(buf, &end); + res = memparse(buf, &end); if (*end != '\0') return -EINVAL; - if (PAGE_ALIGN(*res) >= *res) - *res = PAGE_ALIGN(*res); + if (PAGE_ALIGN(res) >= res) + res = PAGE_ALIGN(res); else - *res = RES_COUNTER_MAX; + res = RES_COUNTER_MAX; + + *resp = res; return 0; } -- 2.39.5