From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx189.postini.com [74.125.245.189]) by kanga.kvack.org (Postfix) with SMTP id 008A76B004A for ; Mon, 12 Mar 2012 03:57:19 -0400 (EDT) Received: by iajr24 with SMTP id r24so8846696iaj.14 for ; Mon, 12 Mar 2012 00:57:19 -0700 (PDT) From: Sha Zhengju Subject: [RESEND, PATCH] memcg: make threshold index in the right position Date: Mon, 12 Mar 2012 15:56:45 +0800 Message-Id: <1331539005-16216-1-git-send-email-handai.szj@taobao.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org, cgroups@vger.kernel.org Cc: kamezawa.hiroyu@jp.fujitsu.com, kirill@shutemov.name, Sha Zhengju From: Sha Zhengju Index current_threshold may point to threshold that just equal to usage after last call of __mem_cgroup_threshold. But after registering or unregistering a new event, it will change (pointing to threshold just below usage). So make it consistent here. For example: now: threshold array: 3 [5] 7 9 (usage = 6, [index] = 5) next turn (after calling __mem_cgroup_threshold): threshold array: 3 5 [7] 9 (usage = 7, [index] = 7) after registering a new event (threshold = 10): threshold array: 3 [5] 7 9 10 (usage = 7, [index] = 5) Signed-off-by: Sha Zhengju Acked-by: KAMEZAWA Hiroyuki Reviewed-by: Kirill A. Shutemov --- mm/memcontrol.c | 11 ++++++----- 1 files changed, 6 insertions(+), 5 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 22d94f5..34737b7 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -183,7 +183,7 @@ struct mem_cgroup_threshold { /* For threshold */ struct mem_cgroup_threshold_ary { - /* An array index points to threshold just below usage. */ + /* An array index points to threshold just below or equal to usage. */ int current_threshold; /* Size of entries[] */ unsigned int size; @@ -4193,7 +4193,7 @@ static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) usage = mem_cgroup_usage(memcg, swap); /* - * current_threshold points to threshold just below usage. + * current_threshold points to threshold just below or equal to usage. * If it's not true, a threshold was crossed after last * call of __mem_cgroup_threshold(). */ @@ -4319,14 +4319,15 @@ static int mem_cgroup_usage_register_event(struct cgroup *cgrp, /* Find current threshold */ new->current_threshold = -1; for (i = 0; i < size; i++) { - if (new->entries[i].threshold < usage) { + if (new->entries[i].threshold <= usage) { /* * new->current_threshold will not be used until * rcu_assign_pointer(), so it's safe to increment * it here. */ ++new->current_threshold; - } + } else + break; } /* Free old spare buffer and save old primary buffer as spare */ @@ -4398,7 +4399,7 @@ static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp, continue; new->entries[j] = thresholds->primary->entries[i]; - if (new->entries[j].threshold < usage) { + if (new->entries[j].threshold <= usage) { /* * new->current_threshold will not be used * until rcu_assign_pointer(), so it's safe to increment -- 1.7.4.1 -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org