From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f47.google.com (mail-ee0-f47.google.com [74.125.83.47]) by kanga.kvack.org (Postfix) with ESMTP id 6B9516B0031 for ; Thu, 13 Feb 2014 11:57:51 -0500 (EST) Received: by mail-ee0-f47.google.com with SMTP id d49so5126874eek.20 for ; Thu, 13 Feb 2014 08:57:50 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTP id x43si5037506eey.82.2014.02.13.08.57.48 for ; Thu, 13 Feb 2014 08:57:49 -0800 (PST) Message-ID: <52FCEE74.9010602@redhat.com> Date: Thu, 13 Feb 2014 11:10:28 -0500 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH 1/2] mm/vmscan: restore sc->gfp_mask after promoting it to __GFP_HIGHMEM References: <000001cf2865$0aa2c0c0$1fe84240$%yang@samsung.com> In-Reply-To: <000001cf2865$0aa2c0c0$1fe84240$%yang@samsung.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Weijie Yang , 'Mel Gorman' Cc: 'Andrew Morton' , 'Minchan Kim' , weijie.yang.kh@gmail.com, 'Linux-MM' , 'linux-kernel' 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; > + 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, 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