From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id 01BA260021B for ; Sat, 2 Jan 2010 00:21:37 -0500 (EST) Received: by iwn41 with SMTP id 41so9518736iwn.12 for ; Fri, 01 Jan 2010 21:21:36 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <1262387986.16572.234.camel@laptop> References: <1262339141-4682-1-git-send-email-kosaki.motohiro@jp.fujitsu.com> <1262387986.16572.234.camel@laptop> Date: Sat, 2 Jan 2010 14:21:36 +0900 Message-ID: <2f11576a1001012121o4f09d30n6dba925e74099da1@mail.gmail.com> Subject: Re: [PATCH] mm, lockdep: annotate reclaim context to zone reclaim too From: KOSAKI Motohiro Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org To: Peter Zijlstra Cc: LKML , linux-mm , Andrew Morton , Nick Piggin , Ingo Molnar List-ID: 2010/1/2 Peter Zijlstra : > On Fri, 2010-01-01 at 18:45 +0900, KOSAKI Motohiro wrote: >> Commit cf40bd16fd (lockdep: annotate reclaim context) introduced reclaim >> context annotation. But it didn't annotate zone reclaim. This patch do it. > > And yet you didn't CC anyone involved in that patch, nor explain why you > think it necessary, massive FAIL. > > The lockdep annotations cover all of kswapd() and direct reclaim through > __alloc_pages_direct_reclaim(). So why would you need an explicit > annotation in __zone_reclaim()? Thanks CCing. The point is zone-reclaim doesn't use __alloc_pages_direct_reclaim. current call graph is __alloc_pages_nodemask get_page_from_freelist zone_reclaim() __alloc_pages_slowpath __alloc_pages_direct_reclaim try_to_free_pages Actually, if zone_reclaim_mode=1, VM never call __alloc_pages_direct_reclaim in usual VM pressure. Thus I think zone-reclaim should be annotated explicitly too. I know almost user don't use zone reclaim mode. but explicit annotation doesn't have any demerit, I think. Am I missing anything? -- 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