From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 075AD9000BD for ; Tue, 27 Sep 2011 20:43:57 -0400 (EDT) Subject: Re: [patch 2/2]vmscan: correctly detect GFP_ATOMIC allocation failure From: Shaohua Li In-Reply-To: <20110927112810.GA3897@tiehlicka.suse.cz> References: <1317108187.29510.201.camel@sli10-conroe> <20110927112810.GA3897@tiehlicka.suse.cz> Content-Type: text/plain; charset="UTF-8" Date: Wed, 28 Sep 2011 08:48:53 +0800 Message-ID: <1317170933.22361.5.camel@sli10-conroe> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Andrew Morton , mel , Rik van Riel , linux-mm On Tue, 2011-09-27 at 19:28 +0800, Michal Hocko wrote: > On Tue 27-09-11 15:23:07, Shaohua Li wrote: > > has_under_min_watermark_zone is used to detect if there is GFP_ATOMIC allocation > > failure risk. For a high end_zone, if any zone below or equal to it has min > > matermark ok, we have no risk. But current logic is any zone has min watermark > > not ok, then we have risk. This is wrong to me. > > This, however, means that we skip congestion_wait more often as ZONE_DMA > tend to be mostly balanced, right? This would mean that kswapd could hog > CPU more. We actually might have more congestion_wait, as now if any zone can meet min watermark, we don't have has_under_min_watermark_zone set so do congestion_wait > Does this fix any particular problem you are seeing? No, just thought the logic is wrong. Thanks, Shaohua -- 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