Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755914Ab1ESCeZ (ORCPT ); Wed, 18 May 2011 22:34:25 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:60783 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755472Ab1ESCeY (ORCPT ); Wed, 18 May 2011 22:34:24 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Message-ID: <4DD481A7.3050108@jp.fujitsu.com> Date: Thu, 19 May 2011 11:34:15 +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, riel@redhat.com Subject: [PATCH v2 3/3] vmscan: implement swap token priority aging References: <4DD480DD.2040307@jp.fujitsu.com> In-Reply-To: <4DD480DD.2040307@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: 4103 Lines: 129 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? Some processes (eg init, auditd, audispd) wake up when a process exiting. And swap token can be get first page-in process when a process exiting makes no swap token owner. Thus such above intermittent running process often get a token. And currently, swap token priority is only decreased at page fault path. Then, if the process sleep immediately after to grab swap token, the swap token priority never be decreased. That's obviously undesirable. This patch implement very poor (and lightweight) priority aging. 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 Reviewed-by: Rik van Riel Reviewed-by: KAMEZAWA Hiroyuki --- include/trace/events/vmscan.h | 20 +++++++++++++------- mm/thrash.c | 11 ++++++++++- 2 files changed, 23 insertions(+), 8 deletions(-) diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h index 1798e0c..b2c33bd 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 +377,21 @@ TRACE_EVENT_CONDITION(update_swap_token_priority, __field(struct mm_struct*, mm) __field(unsigned int, old_prio) __field(unsigned int, new_prio) + __field(struct mm_struct*, swap_token_mm) + __field(unsigned int, swap_token_prio) ), TP_fast_assign( - __entry->mm = mm; - __entry->old_prio = old_prio; - __entry->new_prio = mm->token_priority; + __entry->mm = mm; + __entry->old_prio = old_prio; + __entry->new_prio = mm->token_priority; + __entry->swap_token_mm = swap_token_mm; + __entry->swap_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 swap_token_mm=%p token_prio=%u", + __entry->mm, __entry->old_prio, __entry->new_prio, + __entry->swap_token_mm, __entry->swap_token_prio) ); #endif /* _TRACE_VMSCAN_H */ diff --git a/mm/thrash.c b/mm/thrash.c index 14c6c9f..af46d67 100644 --- a/mm/thrash.c +++ b/mm/thrash.c @@ -25,10 +25,13 @@ #include +#define TOKEN_AGING_INTERVAL (0xFF) + static DEFINE_SPINLOCK(swap_token_lock); struct mm_struct *swap_token_mm; struct mem_cgroup *swap_token_memcg; static unsigned int global_faults; +static unsigned int last_aging; void grab_swap_token(struct mm_struct *mm) { @@ -47,6 +50,11 @@ void grab_swap_token(struct mm_struct *mm) if (!swap_token_mm) goto replace_token; + if ((global_faults - last_aging) > TOKEN_AGING_INTERVAL) { + swap_token_mm->token_priority /= 2; + last_aging = global_faults; + } + if (mm == swap_token_mm) { mm->token_priority += 2; goto update_priority; @@ -64,7 +72,7 @@ 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; @@ -80,6 +88,7 @@ replace_token: trace_replace_swap_token(swap_token_mm, mm); swap_token_mm = mm; swap_token_memcg = memcg; + last_aging = global_faults; goto out; } -- 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/