Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751391AbaFWHtF (ORCPT ); Mon, 23 Jun 2014 03:49:05 -0400 Received: from cantor2.suse.de ([195.135.220.15]:39069 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750723AbaFWHtD (ORCPT ); Mon, 23 Jun 2014 03:49:03 -0400 Date: Mon, 23 Jun 2014 09:49:00 +0200 From: Michal Hocko To: Johannes Weiner Cc: Andrew Morton , Mel Gorman , Rik van Riel , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [patch 1/4] mm: vmscan: remove remains of kswapd-managed zone->all_unreclaimable Message-ID: <20140623074900.GB9743@dhcp22.suse.cz> References: <1403282030-29915-1-git-send-email-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1403282030-29915-1-git-send-email-hannes@cmpxchg.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 20-06-14 12:33:47, Johannes Weiner wrote: > shrink_zones() has a special branch to skip the all_unreclaimable() > check during hibernation, because a frozen kswapd can't mark a zone > unreclaimable. > > But ever since 6e543d5780e3 ("mm: vmscan: fix do_try_to_free_pages() > livelock"), determining a zone to be unreclaimable is done by directly > looking at its scan history and no longer relies on kswapd setting the > per-zone flag. > > Remove this branch and let shrink_zones() check the reclaimability of > the target zones regardless of hibernation state. > > Signed-off-by: Johannes Weiner This code is really tricky :/ But the patch looks good to me. Acked-by: Michal Hocko > --- > mm/vmscan.c | 8 -------- > 1 file changed, 8 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 0f16ffe8eb67..19b5b8016209 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2534,14 +2534,6 @@ out: > if (sc->nr_reclaimed) > return sc->nr_reclaimed; > > - /* > - * As hibernation is going on, kswapd is freezed so that it can't mark > - * the zone into all_unreclaimable. Thus bypassing all_unreclaimable > - * check. > - */ > - if (oom_killer_disabled) > - return 0; > - > /* Aborted reclaim to try compaction? don't OOM, then */ > if (aborted_reclaim) > return 1; > -- > 2.0.0 > -- Michal Hocko SUSE Labs -- 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/