From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4C95BC433F5 for ; Wed, 24 Nov 2021 14:56:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347474AbhKXO7m (ORCPT ); Wed, 24 Nov 2021 09:59:42 -0500 Received: from outbound-smtp57.blacknight.com ([46.22.136.241]:55281 "EHLO outbound-smtp57.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347885AbhKXO7f (ORCPT ); Wed, 24 Nov 2021 09:59:35 -0500 Received: from mail.blacknight.com (pemlinmail02.blacknight.ie [81.17.254.11]) by outbound-smtp57.blacknight.com (Postfix) with ESMTPS id EA194FB06F for ; Wed, 24 Nov 2021 14:56:23 +0000 (GMT) Received: (qmail 25417 invoked from network); 24 Nov 2021 14:56:23 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.17.29]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 24 Nov 2021 14:56:23 -0000 Date: Wed, 24 Nov 2021 14:56:22 +0000 From: Mel Gorman To: Mike Galbraith Cc: lkml Subject: Re: mm: LTP/memcg testcase regression induced by 8cd7c588decf..66ce520bb7c2 series Message-ID: <20211124145621.GJ3366@techsingularity.net> References: <99e779783d6c7fce96448a3402061b9dc1b3b602.camel@gmx.de> <20211123091304.GC3366@techsingularity.net> <21c3489c7ce8342d392c08547a3222a9c289e9fc.camel@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <21c3489c7ce8342d392c08547a3222a9c289e9fc.camel@gmx.de> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 23, 2021 at 12:18:01PM +0100, Mike Galbraith wrote: > On Tue, 2021-11-23 at 09:13 +0000, Mel Gorman wrote: > > > > I'll see can I reproduce this... > > You likely already know this, but just in case, just plunk the below > into $LTPROOT/runtest/foo, and $LTPROOT/runltp -f foo. > > #DESCRIPTION:Resource Management testing > memcg_regression memcg_regression_test.sh > Thanks. Can you try the following patch please? The test will still take longer to reach OOM and complete as it's stalling but not as severely. diff --git a/mm/vmscan.c b/mm/vmscan.c index 07db03883062..d9166e94eb95 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1057,7 +1057,17 @@ void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason) break; case VMSCAN_THROTTLE_NOPROGRESS: - timeout = HZ/2; + timeout = 1; + + /* + * If kswapd is disabled, reschedule if necessary but do not + * throttle as the system is likely near OOM. + */ + if (pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES) { + cond_resched(); + return; + } + break; case VMSCAN_THROTTLE_ISOLATED: timeout = HZ/50; @@ -3395,7 +3405,7 @@ static void consider_reclaim_throttle(pg_data_t *pgdat, struct scan_control *sc) return; /* Throttle if making no progress at high prioities. */ - if (sc->priority < DEF_PRIORITY - 2) + if (sc->priority < DEF_PRIORITY - 2 && !sc->nr_reclaimed) reclaim_throttle(pgdat, VMSCAN_THROTTLE_NOPROGRESS); } @@ -3415,6 +3425,7 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc) unsigned long nr_soft_scanned; gfp_t orig_mask; pg_data_t *last_pgdat = NULL; + pg_data_t *first_pgdat = NULL; /* * If the number of buffer_heads in the machine exceeds the maximum @@ -3478,14 +3489,18 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc) /* need some check for avoid more shrink_zone() */ } + if (!first_pgdat) + first_pgdat = zone->zone_pgdat; + /* See comment about same check for global reclaim above */ if (zone->zone_pgdat == last_pgdat) continue; last_pgdat = zone->zone_pgdat; shrink_node(zone->zone_pgdat, sc); - consider_reclaim_throttle(zone->zone_pgdat, sc); } + consider_reclaim_throttle(first_pgdat, sc); + /* * Restore to original mask to avoid the impact on the caller if we * promoted it to __GFP_HIGHMEM.