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 ESMTP id 84A936B004D for ; Mon, 27 Jul 2009 20:14:39 -0400 (EDT) Received: from wpaz1.hot.corp.google.com (wpaz1.hot.corp.google.com [172.24.198.65]) by smtp-out.google.com with ESMTP id n6S0EbAf017213 for ; Tue, 28 Jul 2009 01:14:39 +0100 Received: from pxi27 (pxi27.prod.google.com [10.243.27.27]) by wpaz1.hot.corp.google.com with ESMTP id n6S0EYlm010950 for ; Mon, 27 Jul 2009 17:14:35 -0700 Received: by pxi27 with SMTP id 27so2345033pxi.20 for ; Mon, 27 Jul 2009 17:14:34 -0700 (PDT) Date: Mon, 27 Jul 2009 17:14:32 -0700 (PDT) From: David Rientjes Subject: Re: [BUG] set_mempolicy(MPOL_INTERLEAV) cause kernel panic In-Reply-To: <20090728085810.f7ae678a.kamezawa.hiroyu@jp.fujitsu.com> Message-ID: References: <20090715182320.39B5.A69D9226@jp.fujitsu.com> <1247679064.4089.26.camel@useless.americas.hpqcorp.net> <20090724160936.a3b8ad29.akpm@linux-foundation.org> <337c5d83954b38b14a17f0adf4d357d8.squirrel@webmail-b.css.fujitsu.com> <5bb65c0e4c6828b1331d33745f34d9ee.squirrel@webmail-b.css.fujitsu.com> <9443f91bd4648e6214b32acff4512b97.squirrel@webmail-b.css.fujitsu.com> <20090728085810.f7ae678a.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: Andrew Morton , Lee Schermerhorn , KOSAKI Motohiro , miaox@cn.fujitsu.com, Ingo Molnar , Peter Zijlstra , Christoph Lameter , Paul Menage , Nick Piggin , y-goto@jp.fujitsu.com, Pekka Enberg , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Tue, 28 Jul 2009, KAMEZAWA Hiroyuki wrote: > > The nodemask for each task is updated to reflect the removal of a node and > > it calls mpol_rebind_mm() with the new nodemask. > > > yes, but _not_ updated at online. > Well, I disagreed that we needed to alter any pre-existing mempolicies for MEM_GOING_ONLINE or MEM_ONLINE since it may diverge from the original intent of the policy. MPOL_PREFERRED certain shouldn't change, MPOL_INTERLEAVE would be unbalanced, and MPOL_BIND could diverge from memory isolation or affinity requirements. I'd be interested to hear any real world use cases for MEM_ONLINE updating of mempolicies. > What I felt at reading cpuset/mempolicy again is that it's too complex ;) > The 1st question is why mems_allowed which can be 1024bytes when max_node=4096 > is copied per tasks.... The page allocator needs lockless access to mems_allowed. -- 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