Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757308Ab1EMLkc (ORCPT ); Fri, 13 May 2011 07:40:32 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:44772 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752826Ab1EMLkb (ORCPT ); Fri, 13 May 2011 07:40:31 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Message-ID: <4DCD1913.2090200@jp.fujitsu.com> Date: Fri, 13 May 2011 20:42:11 +0900 From: KOSAKI Motohiro User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; ja; rv:1.9.2.17) Gecko/20110414 Lightning/1.0b2 Thunderbird/3.1.10 MIME-Version: 1.0 To: kosaki.motohiro@jp.fujitsu.com CC: linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, kamezawa.hiroyu@jp.fujitsu.com, minchan.kim@gmail.com, riel@redhat.com Subject: [PATCH 3/3] vmscan: implement swap token priority decay References: <4DCD1824.1060801@jp.fujitsu.com> In-Reply-To: <4DCD1824.1060801@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2938 Lines: 92 While testing for memcg aware swap token, I observed a swap token was often grabbed an intermittent running process (eg init, auditd) and they never release a token. Why? Currently, swap toke priority is only decreased at page fault path. Then, if the process sleep immediately after to grab swap token, their swap token priority never be decreased. That makes obviously undesired result. This patch implement very poor (and lightweight) priority decay mechanism. It only be affect to the above corner case and doesn't change swap tendency workload performance (eg multi process qsbench load) Signed-off-by: KOSAKI Motohiro --- include/trace/events/vmscan.h | 12 ++++++++---- mm/thrash.c | 5 ++++- 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h index 1798e0c..ba18137 100644 --- a/include/trace/events/vmscan.h +++ b/include/trace/events/vmscan.h @@ -366,9 +366,10 @@ DEFINE_EVENT_CONDITION(put_swap_token_template, disable_swap_token, TRACE_EVENT_CONDITION(update_swap_token_priority, TP_PROTO(struct mm_struct *mm, - unsigned int old_prio), + unsigned int old_prio, + struct mm_struct *swap_token_mm), - TP_ARGS(mm, old_prio), + TP_ARGS(mm, old_prio, swap_token_mm), TP_CONDITION(mm->token_priority != old_prio), @@ -376,16 +377,19 @@ TRACE_EVENT_CONDITION(update_swap_token_priority, __field(struct mm_struct*, mm) __field(unsigned int, old_prio) __field(unsigned int, new_prio) + __field(unsigned int, token_prio) ), TP_fast_assign( __entry->mm = mm; __entry->old_prio = old_prio; __entry->new_prio = mm->token_priority; + __entry->token_prio = swap_token_mm ? swap_token_mm->token_priority : 0; ), - TP_printk("mm=%p old_prio=%u new_prio=%u", - __entry->mm, __entry->old_prio, __entry->new_prio) + TP_printk("mm=%p old_prio=%u new_prio=%u token_prio=%u", + __entry->mm, __entry->old_prio, __entry->new_prio, + __entry->token_prio) ); #endif /* _TRACE_VMSCAN_H */ diff --git a/mm/thrash.c b/mm/thrash.c index 14c6c9f..0c4f0a8 100644 --- a/mm/thrash.c +++ b/mm/thrash.c @@ -47,6 +47,9 @@ void grab_swap_token(struct mm_struct *mm) if (!swap_token_mm) goto replace_token; + if (!(global_faults & 0xff)) + mm->token_priority /= 2; + if (mm == swap_token_mm) { mm->token_priority += 2; goto update_priority; @@ -64,7 +67,7 @@ void grab_swap_token(struct mm_struct *mm) goto replace_token; update_priority: - trace_update_swap_token_priority(mm, old_prio); + trace_update_swap_token_priority(mm, old_prio, swap_token_mm); out: mm->faultstamp = global_faults; -- 1.7.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/