From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx112.postini.com [74.125.245.112]) by kanga.kvack.org (Postfix) with SMTP id 268C26B0158 for ; Wed, 1 May 2013 02:28:26 -0400 (EDT) Received: by mail-ia0-f169.google.com with SMTP id l29so1162354iag.0 for ; Tue, 30 Apr 2013 23:28:25 -0700 (PDT) Message-ID: <5180B601.8080005@gmail.com> Date: Wed, 01 May 2013 14:28:17 +0800 From: Will Huck MIME-Version: 1.0 Subject: Re: [RFC PATCH 0/3] Obey mark_page_accessed hint given by filesystems References: <1367253119-6461-1-git-send-email-mgorman@suse.de> In-Reply-To: <1367253119-6461-1-git-send-email-mgorman@suse.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Alexey Lyahkov , Andrew Perepechko , Robin Dong , Theodore Tso , Andrew Morton , Hugh Dickins , Rik van Riel , Johannes Weiner , Bernd Schubert , David Howells , Trond Myklebust , Linux-fsdevel , Linux-ext4 , LKML , Linux-mm Hi Mel, On 04/30/2013 12:31 AM, Mel Gorman wrote: > Andrew Perepechko reported a problem whereby pages are being prematurely > evicted as the mark_page_accessed() hint is ignored for pages that are > currently on a pagevec -- http://www.spinics.net/lists/linux-ext4/msg37340.html . > Alexey Lyahkov and Robin Dong have also reported problems recently that > could be due to hot pages reaching the end of the inactive list too quickly > and be reclaimed. Both shrink_active_list and shrink_inactive_list can call lru_add_drain(), why the hot pages can't be mark Actived during this time? > Rather than addressing this on a per-filesystem basis, this series aims > to fix the mark_page_accessed() interface by deferring what LRU a page > is added to pagevec drain time and allowing mark_page_accessed() to call > SetPageActive on a pagevec page. This opens some important races that > I think should be harmless but needs double checking. The races and the > VM_BUG_ON checks that are removed are all described in patch 2. > > This series received only very light testing but it did not immediately > blow up and a debugging patch confirmed that pages are now getting added > to the active file LRU list that would previously have been added to the > inactive list. > > fs/cachefiles/rdwr.c | 30 ++++++------------------ > fs/nfs/dir.c | 7 ++---- > include/linux/pagevec.h | 34 +-------------------------- > mm/swap.c | 61 ++++++++++++++++++++++++------------------------- > mm/vmscan.c | 3 --- > 5 files changed, 40 insertions(+), 95 deletions(-) > -- 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