Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751742AbaBNDjr (ORCPT ); Thu, 13 Feb 2014 22:39:47 -0500 Received: from mail-ie0-f169.google.com ([209.85.223.169]:46229 "EHLO mail-ie0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751050AbaBNDjp (ORCPT ); Thu, 13 Feb 2014 22:39:45 -0500 MIME-Version: 1.0 In-Reply-To: <52FCEE74.9010602@redhat.com> References: <000001cf2865$0aa2c0c0$1fe84240$%yang@samsung.com> <52FCEE74.9010602@redhat.com> Date: Fri, 14 Feb 2014 11:39:45 +0800 Message-ID: Subject: Re: [PATCH 1/2] mm/vmscan: restore sc->gfp_mask after promoting it to __GFP_HIGHMEM From: Weijie Yang To: Rik van Riel Cc: Weijie Yang , Mel Gorman , Andrew Morton , Minchan Kim , Linux-MM , linux-kernel Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 14, 2014 at 12:10 AM, Rik van Riel wrote: > On 02/12/2014 09:39 PM, Weijie Yang wrote: > >> --- a/mm/vmscan.c >> +++ b/mm/vmscan.c >> @@ -2298,14 +2298,17 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc) >> unsigned long nr_soft_reclaimed; >> unsigned long nr_soft_scanned; >> bool aborted_reclaim = false; >> + bool promoted_mask = false; >> >> /* >> * If the number of buffer_heads in the machine exceeds the maximum >> * allowed level, force direct reclaim to scan the highmem zone as >> * highmem pages could be pinning lowmem pages storing buffer_heads >> */ >> - if (buffer_heads_over_limit) >> + if (buffer_heads_over_limit) { > > It took me a minute to figure out why you are doing things this way, > so maybe this could use a comment, or maybe it could be done in a > simpler way, by simply saving and restoring the original mask? > orig_mask = sc->gfp_mask; Yes, you are right. This simpler way is better. I will turn to it in V2 resend patch. Thanks! >> + promoted_mask = !(sc->gfp_mask & __GFP_HIGHMEM); >> sc->gfp_mask |= __GFP_HIGHMEM; >> + } >> >> for_each_zone_zonelist_nodemask(zone, z, zonelist, >> gfp_zone(sc->gfp_mask), sc->nodemask) { >> @@ -2354,6 +2357,9 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc) >> shrink_zone(zone, sc); >> } >> >> + if (promoted_mask) > sc->gfp_mask = orig_mask; > >> + sc->gfp_mask &= ~__GFP_HIGHMEM; >> + >> return aborted_reclaim; >> } >> >> > > > -- > All rights reversed -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/