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authorSha Zhengju <handai.szj@taobao.com>2013-09-12 15:13:49 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-09-12 15:38:02 -0700
commit1a36e59d4833de19120dc7482c61ef69e228c73c (patch)
tree85b815d4b6a461d56d4a0a450e31fa069c7c1142 /kernel
parentmemcg: avoid overflow caused by PAGE_ALIGN (diff)
downloadlinux-dev-1a36e59d4833de19120dc7482c61ef69e228c73c.tar.xz
linux-dev-1a36e59d4833de19120dc7482c61ef69e228c73c.zip
memcg: reduce function dereference
This function dereferences res far too often, so optimize it. Signed-off-by: Sha Zhengju <handai.szj@taobao.com> Signed-off-by: Qiang Huang <h.huangqiang@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Jeff Liu <jeff.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/res_counter.c19
1 files 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;
}