From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id E502A600385 for ; Mon, 17 May 2010 12:13:21 -0400 (EDT) Date: Mon, 17 May 2010 11:09:31 -0500 (CDT) From: Christoph Lameter Subject: Re: [PATCH 3/3] mem-hotplug: fix potential race while building zonelist for new populated zone In-Reply-To: <4BF0FC4C.4060306@linux.intel.com> Message-ID: References: <4BF0FC4C.4060306@linux.intel.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Haicheng Li Cc: "linux-mm@kvack.org" , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" , "Wu, Fengguang" , Andi Kleen , Mel Gorman , Tejun Heo List-ID: On Mon, 17 May 2010, Haicheng Li wrote: > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 72c1211..0729a82 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -2783,6 +2783,20 @@ static __init_refok int __build_all_zonelists(void > *data) > { > int nid; > int cpu; > +#ifdef CONFIG_MEMORY_HOTPLUG > + struct zone_online_info *new = (struct zone_online_info *)data; > + > + /* > + * Populate the new zone before build zonelists, which could > + * happen only when onlining a new node after system is booted. > + */ > + if (new) { > + /* We are expecting a new memory block here. */ > + WARN_ON(!new->onlined_pages); > + new->zone->present_pages += new->onlined_pages; > + new->zone->zone_pgdat->node_present_pages += > new->onlined_pages; > + } > +#endif Building a zonelist now has the potential side effect of changes to the size of the zone? Can we have a global mutex that protects against size modification of zonelists instead? And it could also serialize the pageset setup? -- 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