From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-f179.google.com (mail-ie0-f179.google.com [209.85.223.179]) by kanga.kvack.org (Postfix) with ESMTP id 2124C6B005C for ; Fri, 29 Aug 2014 05:12:22 -0400 (EDT) Received: by mail-ie0-f179.google.com with SMTP id tr6so2459215ieb.10 for ; Fri, 29 Aug 2014 02:12:21 -0700 (PDT) Received: from mail-ig0-x235.google.com (mail-ig0-x235.google.com [2607:f8b0:4001:c05::235]) by mx.google.com with ESMTPS id fg11si6666247icb.51.2014.08.29.02.12.21 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 29 Aug 2014 02:12:21 -0700 (PDT) Received: by mail-ig0-f181.google.com with SMTP id h15so2290589igd.14 for ; Fri, 29 Aug 2014 02:12:21 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20140829081211.GF12424@suse.de> References: <000001cfc357$74db64a0$5e922de0$%yang@samsung.com> <20140829081211.GF12424@suse.de> Date: Fri, 29 Aug 2014 17:12:21 +0800 Message-ID: Subject: Re: [PATCH] mm: page_alloc: avoid wakeup kswapd on the unintended node From: Weijie Yang Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Weijie Yang , Andrew Morton , Rik van Riel , Johannes Weiner , rientjes@google.com, linux-kernel , Linux-MM On Fri, Aug 29, 2014 at 4:12 PM, Mel Gorman wrote: > On Fri, Aug 29, 2014 at 03:03:19PM +0800, Weijie Yang wrote: >> When enter page_alloc slowpath, we wakeup kswapd on every pgdat >> according to the zonelist and high_zoneidx. However, this doesn't >> take nodemask into account, and could prematurely wakeup kswapd on >> some unintended nodes. >> >> This patch uses for_each_zone_zonelist_nodemask() instead of >> for_each_zone_zonelist() in wake_all_kswapds() to avoid the above situation. >> >> Signed-off-by: Weijie Yang > > Just out of curiousity, did you measure a problem due to this or is > the patch due to code inspection? It was known that we examined useless > nodes but assumed to not be a problem because the watermark check should > prevent spurious wakeups. However, we do a cpuset check and this patch > is consistent with that so regardless of why you wrote the patch It is a patch due to code review :-) > Acked-by: Mel Gorman > > -- > Mel Gorman > SUSE Labs -- 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