From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935390AbdADK5e (ORCPT ); Wed, 4 Jan 2017 05:57:34 -0500 Received: from mx2.suse.de ([195.135.220.15]:58488 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753342AbdADK53 (ORCPT ); Wed, 4 Jan 2017 05:57:29 -0500 Date: Wed, 4 Jan 2017 11:56:29 +0100 From: Michal Hocko To: Vlastimil Babka Cc: Andrew Morton , David Rientjes , Johannes Weiner , linux-mm@kvack.org, LKML Subject: Re: [PATCH 3/3] oom, trace: add compaction retry tracepoint Message-ID: <20170104105629.GF25453@dhcp22.suse.cz> References: <20161220130135.15719-1-mhocko@kernel.org> <20161220130135.15719-4-mhocko@kernel.org> <6f3a808d-7799-80f5-9c00-4fb996dc31fa@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6f3a808d-7799-80f5-9c00-4fb996dc31fa@suse.cz> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 04-01-17 11:47:56, Vlastimil Babka wrote: > On 12/20/2016 02:01 PM, Michal Hocko wrote: > > From: Michal Hocko > > > > Higher order requests oom debugging is currently quite hard. We do have > > some compaction points which can tell us how the compaction is operating > > but there is no trace point to tell us about compaction retry logic. > > This patch adds a one which will have the following format > > > > bash-3126 [001] .... 1498.220001: compact_retry: order=9 priority=COMPACT_PRIO_SYNC_LIGHT compaction_result=withdrawn retries=0 max_retries=16 should_retry=0 > > > > we can see that the order 9 request is not retried even though we are in > > the highest compaction priority mode becase the last compaction attempt > > was withdrawn. This means that compaction_zonelist_suitable must have > > returned false and there is no suitable zone to compact for this request > > and so no need to retry further. > > > > another example would be > > <...>-3137 [001] .... 81.501689: compact_retry: order=9 priority=COMPACT_PRIO_SYNC_LIGHT compaction_result=failed retries=0 max_retries=16 should_retry=0 > > > > in this case the order-9 compaction failed to find any suitable > > block. We do not retry anymore because this is a costly request > > and those do not go below COMPACT_PRIO_SYNC_LIGHT priority. > > > > Changes since v1 > > - fix compaction_result into highlevel constants translation as per > > Vlastimil > > > > Signed-off-by: Michal Hocko > > Acked-by: Vlastimil Babka > > Hmm I've noticed that I didn't suggest the following below here, > although I did for the vmscan tracepoints now. How about adding this > -fix for consistency? > > --------8<-------- > From: Vlastimil Babka > Date: Wed, 4 Jan 2017 11:44:09 +0100 > Subject: [PATCH] oom, trace: add compaction retry tracepoint-fix > > Let's print the compaction priorities lower-case and without > prefix for consistency. > > Also indent fix in compact_result_to_feedback(). > > Signed-off-by: Vlastimil Babka I would just worry that c&p constant name is easier to work with when vim -t $PRIO or git grep $PRIO. But if the lowercase and shorter sounds better to you then no objections from me. > --- > include/trace/events/mmflags.h | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h > index aa4caa6914a9..e4c3a0febcce 100644 > --- a/include/trace/events/mmflags.h > +++ b/include/trace/events/mmflags.h > @@ -195,7 +195,7 @@ IF_HAVE_VM_SOFTDIRTY(VM_SOFTDIRTY, "softdirty" ) \ > > #define compact_result_to_feedback(result) \ > ({ \ > - enum compact_result __result = result; \ > + enum compact_result __result = result; \ > (compaction_failed(__result)) ? COMPACTION_FAILED : \ > (compaction_withdrawn(__result)) ? COMPACTION_WITHDRAWN : COMPACTION_PROGRESS; \ > }) > @@ -206,9 +206,9 @@ IF_HAVE_VM_SOFTDIRTY(VM_SOFTDIRTY, "softdirty" ) \ > EMe(COMPACTION_PROGRESS, "progress") > > #define COMPACTION_PRIORITY \ > - EM(COMPACT_PRIO_SYNC_FULL, "COMPACT_PRIO_SYNC_FULL") \ > - EM(COMPACT_PRIO_SYNC_LIGHT, "COMPACT_PRIO_SYNC_LIGHT") \ > - EMe(COMPACT_PRIO_ASYNC, "COMPACT_PRIO_ASYNC") > + EM(COMPACT_PRIO_SYNC_FULL, "sync_full") \ > + EM(COMPACT_PRIO_SYNC_LIGHT, "sync_light") \ > + EMe(COMPACT_PRIO_ASYNC, "async") > #else > #define COMPACTION_STATUS > #define COMPACTION_PRIORITY > -- > 2.11.0 > -- Michal Hocko SUSE Labs