From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx206.postini.com [74.125.245.206]) by kanga.kvack.org (Postfix) with SMTP id 7D2BC6B01F4 for ; Wed, 1 May 2013 18:30:55 -0400 (EDT) Received: by mail-pd0-f170.google.com with SMTP id 15so1022660pdi.29 for ; Wed, 01 May 2013 15:30:54 -0700 (PDT) Date: Wed, 1 May 2013 15:30:52 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH 4/4] memory_hotplug: use pgdat_resize_lock() when updating node_present_pages In-Reply-To: <1367446635-12856-5-git-send-email-cody@linux.vnet.ibm.com> Message-ID: References: <1367446635-12856-1-git-send-email-cody@linux.vnet.ibm.com> <1367446635-12856-5-git-send-email-cody@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Cody P Schafer Cc: Andrew Morton , Linux MM , LKML On Wed, 1 May 2013, Cody P Schafer wrote: > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index a221fac..0bdca10 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -915,6 +915,7 @@ static void node_states_set_node(int node, struct memory_notify *arg) > > int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type) > { > + unsigned long flags; > unsigned long onlined_pages = 0; > struct zone *zone; > int need_zonelists_rebuild = 0; > @@ -993,7 +994,11 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ > > zone->managed_pages += onlined_pages; > zone->present_pages += onlined_pages; > + > + pgdat_resize_lock(zone->zone_pgdat, &flags); > zone->zone_pgdat->node_present_pages += onlined_pages; > + pgdat_resize_unlock(zone->zone_pgdat, &flags); > + > if (onlined_pages) { > node_states_set_node(zone_to_nid(zone), &arg); > if (need_zonelists_rebuild) Why? You can't get a partial read of a word-sized data structure. -- 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