From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753425Ab0BYIBl (ORCPT ); Thu, 25 Feb 2010 03:01:41 -0500 Received: from smtp-out.google.com ([216.239.33.17]:30312 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753338Ab0BYIBk (ORCPT ); Thu, 25 Feb 2010 03:01:40 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id: references:user-agent:mime-version:content-type:x-system-of-record; b=GE4M6fpOfVEDIDGC6O97b38OCj/HpdXPT1nrm0vhkSfTkSYxe44cseBC02hM9HjpZ ACorW+HSsv1LBaWlaKY1g== Date: Thu, 25 Feb 2010 00:01:30 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Pekka Enberg cc: Christoph Lameter , Andi Kleen , Nick Piggin , linux-kernel@vger.kernel.org, linux-mm@kvack.org, haicheng.li@intel.com Subject: Re: [PATCH] [4/4] SLAB: Fix node add timer race in cache_reap In-Reply-To: <4B862623.5090608@cs.helsinki.fi> Message-ID: References: <20100211953.850854588@firstfloor.org> <20100211205404.085FEB1978@basil.firstfloor.org> <20100215061535.GI5723@laptop> <20100215103250.GD21783@one.firstfloor.org> <20100215104135.GM5723@laptop> <20100215105253.GE21783@one.firstfloor.org> <20100215110135.GN5723@laptop> <20100220090154.GB11287@basil.fritz.box> <4B862623.5090608@cs.helsinki.fi> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 25 Feb 2010, Pekka Enberg wrote: > > > > > I'm just worried there is still an underlying problem here. > > > > So am I. What caused the breakage that requires this patchset? > > > Memory hotadd with a new node being onlined. > > > > That used to work fine. > > OK, can we get this issue resolved? The merge window is open and Christoph > seems to be unhappy with the whole patch queue. I'd hate this bug fix to miss > .34... > I don't see how memory hotadd with a new node being onlined could have worked fine before since slab lacked any memory hotplug notifier until Andi just added it. That said, I think the first and fourth patch in this series may be unnecessary if slab's notifier were to call slab_node_prepare() on MEM_GOING_ONLINE instead of MEM_ONLINE. Otherwise, kswapd is already running, the zonelists for the new pgdat have been initialized, and the bit has been set in node_states[N_HIGH_MEMORY] without allocated cachep->nodelists[node] memory. 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 ESMTP id 8259E6B0047 for ; Thu, 25 Feb 2010 03:01:47 -0500 (EST) Received: from wpaz13.hot.corp.google.com (wpaz13.hot.corp.google.com [172.24.198.77]) by smtp-out.google.com with ESMTP id o1P81hvl016880 for ; Thu, 25 Feb 2010 08:01:44 GMT Received: from pzk15 (pzk15.prod.google.com [10.243.19.143]) by wpaz13.hot.corp.google.com with ESMTP id o1P81gfk006452 for ; Thu, 25 Feb 2010 00:01:42 -0800 Received: by pzk15 with SMTP id 15so716709pzk.20 for ; Thu, 25 Feb 2010 00:01:42 -0800 (PST) Date: Thu, 25 Feb 2010 00:01:30 -0800 (PST) From: David Rientjes Subject: Re: [PATCH] [4/4] SLAB: Fix node add timer race in cache_reap In-Reply-To: <4B862623.5090608@cs.helsinki.fi> Message-ID: References: <20100211953.850854588@firstfloor.org> <20100211205404.085FEB1978@basil.firstfloor.org> <20100215061535.GI5723@laptop> <20100215103250.GD21783@one.firstfloor.org> <20100215104135.GM5723@laptop> <20100215105253.GE21783@one.firstfloor.org> <20100215110135.GN5723@laptop> <20100220090154.GB11287@basil.fritz.box> <4B862623.5090608@cs.helsinki.fi> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Pekka Enberg Cc: Christoph Lameter , Andi Kleen , Nick Piggin , linux-kernel@vger.kernel.org, linux-mm@kvack.org, haicheng.li@intel.com List-ID: On Thu, 25 Feb 2010, Pekka Enberg wrote: > > > > > I'm just worried there is still an underlying problem here. > > > > So am I. What caused the breakage that requires this patchset? > > > Memory hotadd with a new node being onlined. > > > > That used to work fine. > > OK, can we get this issue resolved? The merge window is open and Christoph > seems to be unhappy with the whole patch queue. I'd hate this bug fix to miss > .34... > I don't see how memory hotadd with a new node being onlined could have worked fine before since slab lacked any memory hotplug notifier until Andi just added it. That said, I think the first and fourth patch in this series may be unnecessary if slab's notifier were to call slab_node_prepare() on MEM_GOING_ONLINE instead of MEM_ONLINE. Otherwise, kswapd is already running, the zonelists for the new pgdat have been initialized, and the bit has been set in node_states[N_HIGH_MEMORY] without allocated cachep->nodelists[node] memory. -- 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/ . 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