From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id CEED26B0011 for ; Wed, 18 May 2011 22:34:25 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp (unknown [10.0.50.71]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 0CFE53EE0BB for ; Thu, 19 May 2011 11:34:23 +0900 (JST) Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id DAFBE45DE5D for ; Thu, 19 May 2011 11:34:22 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id C157045DE58 for ; Thu, 19 May 2011 11:34:22 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id AF2F0E08002 for ; Thu, 19 May 2011 11:34:22 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.240.81.134]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 74CE4E08001 for ; Thu, 19 May 2011 11:34:22 +0900 (JST) Message-ID: <4DD481A7.3050108@jp.fujitsu.com> Date: Thu, 19 May 2011 11:34:15 +0900 From: KOSAKI Motohiro MIME-Version: 1.0 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: owner-linux-mm@kvack.org List-ID: 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 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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