From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id B7F776B006A for ; Wed, 17 Jun 2009 13:33:34 -0400 (EDT) Received: from localhost (smtp.ultrahosting.com [127.0.0.1]) by smtp.ultrahosting.com (Postfix) with ESMTP id 4C34382C4C0 for ; Wed, 17 Jun 2009 13:50:52 -0400 (EDT) Received: from smtp.ultrahosting.com ([74.213.175.254]) by localhost (smtp.ultrahosting.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id xtlzEWID4adE for ; Wed, 17 Jun 2009 13:50:52 -0400 (EDT) Received: from gentwo.org (unknown [74.213.171.31]) by smtp.ultrahosting.com (Postfix) with ESMTP id 20D4782C4CC for ; Wed, 17 Jun 2009 13:50:46 -0400 (EDT) Date: Wed, 17 Jun 2009 13:34:26 -0400 (EDT) From: Christoph Lameter Subject: Re: + page_alloc-oops-when-setting-percpu_pagelist_fraction.patch added to -mm tree In-Reply-To: <20090617140053.GB32637@sgi.com> Message-ID: References: <200906161901.n5GJ1osY026940@imap1.linux-foundation.org> <20090617091040.99BB.A69D9226@jp.fujitsu.com> <20090617140053.GB32637@sgi.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Dimitri Sivanich Cc: KOSAKI Motohiro , mel@csn.ul.ie, nickpiggin@yahoo.com.au, linux-mm , LKML , akpm@linux-foundation.org List-ID: On Wed, 17 Jun 2009, Dimitri Sivanich wrote: > > pcp is only protected local_irq_save(), not spin lock. it assume > > each cpu have different own pcp. but this patch break this assumption. > > Now, we can share boot_pageset by multiple cpus. > > > > I'm not quite understanding what you mean. > > Prior to the cpu going down, each unpopulated zone pointed to the boot_pageset (per_cpu_pageset) for it's cpu (it's array element), so things had been set up this way already. I could be missing something, but am not sure why restoring this would be a risk? The boot_pageset is supposed to be per cpu and this patch preserves it. However, all zones for a cpu have just a single boot pageset. Maybe that was what threw off Kosaki? -- 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