From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx196.postini.com [74.125.245.196]) by kanga.kvack.org (Postfix) with SMTP id 205F56B0031 for ; Thu, 1 Aug 2013 23:25:57 -0400 (EDT) From: Qiang Huang Subject: [PATCH v2 4/4] memcg: reduce function dereference Date: Fri, 2 Aug 2013 11:25:33 +0800 Message-ID: <1375413933-10732-5-git-send-email-h.huangqiang@huawei.com> In-Reply-To: <1375413933-10732-1-git-send-email-h.huangqiang@huawei.com> References: <1375413933-10732-1-git-send-email-h.huangqiang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: mhocko@suse.cz, lizefan@huawei.com, handai.szj@taobao.com, handai.szj@gmail.com, jeff.liu@oracle.com, nishimura@mxp.nes.nec.co.jp, cgroups@vger.kernel.org, linux-mm@kvack.org From: Sha Zhengju This function dereferences res far too often, so optimize it. Signed-off-by: Sha Zhengju Signed-off-by: Qiang Huang Reviewed-by: Michal Hocko --- 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 085d3ae..4aa8a30 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; } -- 1.8.3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org