From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752281Ab1GLJkR (ORCPT ); Tue, 12 Jul 2011 05:40:17 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:59423 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751574Ab1GLJkP (ORCPT ); Tue, 12 Jul 2011 05:40:15 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Message-ID: <4E1C1684.4090706@jp.fujitsu.com> Date: Tue, 12 Jul 2011 18:40:20 +0900 From: KOSAKI Motohiro User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; ja; rv:1.9.2.18) Gecko/20110616 Lightning/1.0b2 Thunderbird/3.1.11 MIME-Version: 1.0 To: minchan.kim@gmail.com CC: mgorman@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cl@linux.com Subject: Re: [PATCH 1/3] mm: vmscan: Do use use PF_SWAPWRITE from zone_reclaim References: <1310389274-13995-1-git-send-email-mgorman@suse.de> <1310389274-13995-2-git-send-email-mgorman@suse.de> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (2011/07/12 18:27), Minchan Kim wrote: > Hi Mel, > > On Mon, Jul 11, 2011 at 10:01 PM, Mel Gorman wrote: >> Zone reclaim is similar to direct reclaim in a number of respects. >> PF_SWAPWRITE is used by kswapd to avoid a write-congestion check >> but it's set also set for zone_reclaim which is inappropriate. >> Setting it potentially allows zone_reclaim users to cause large IO >> stalls which is worse than remote memory accesses. > > As I read zone_reclaim_mode in vm.txt, I think it's intentional. > It has meaning of throttle the process which are writing large amounts > of data. The point is to prevent use of remote node's free memory. > > And we has still the comment. If you're right, you should remove comment. > " * and we also need to be able to write out pages for RECLAIM_WRITE > * and RECLAIM_SWAP." > > > And at least, we should Cc Christoph and KOSAKI. Of course, I'll take full ack this. Do you remember I posted the same patch about one year ago. At that time, Mel disagreed me and I'm glad to see he changed the mind. :) > >> >> Signed-off-by: Mel Gorman >> --- >> mm/vmscan.c | 4 ++-- >> 1 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/mm/vmscan.c b/mm/vmscan.c >> index 4f49535..ebef213 100644 >> --- a/mm/vmscan.c >> +++ b/mm/vmscan.c >> @@ -3063,7 +3063,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) >> * and we also need to be able to write out pages for RECLAIM_WRITE >> * and RECLAIM_SWAP. >> */ >> - p->flags |= PF_MEMALLOC | PF_SWAPWRITE; >> + p->flags |= PF_MEMALLOC; >> lockdep_set_current_reclaim_state(gfp_mask); >> reclaim_state.reclaimed_slab = 0; >> p->reclaim_state = &reclaim_state; >> @@ -3116,7 +3116,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) >> } >> >> p->reclaim_state = NULL; >> - current->flags &= ~(PF_MEMALLOC | PF_SWAPWRITE); >> + current->flags &= ~PF_MEMALLOC; >> lockdep_clear_current_reclaim_state(); >> return sc.nr_reclaimed >= nr_pages; >> } >> -- >> 1.7.3.4 >> >> -- >> 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 >> > > >