From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753402AbcLNSLk (ORCPT ); Wed, 14 Dec 2016 13:11:40 -0500 Received: from mail-wj0-f194.google.com ([209.85.210.194]:33108 "EHLO mail-wj0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751014AbcLNSLi (ORCPT ); Wed, 14 Dec 2016 13:11:38 -0500 Date: Wed, 14 Dec 2016 19:11:34 +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: <20161214181133.GB16763@dhcp22.suse.cz> References: <20161214145324.26261-1-mhocko@kernel.org> <20161214145324.26261-4-mhocko@kernel.org> <60cfb7ca-fb95-7a34-bae2-9b7c49119573@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <60cfb7ca-fb95-7a34-bae2-9b7c49119573@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 14-12-16 18:28:38, Vlastimil Babka wrote: > On 12/14/2016 03:53 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 bash-3126 [001] .... 1498.220001: compact_retry: order=9 priority=COMPACT_PRIO_SYNC_LIGHT compaction_result=withdrawn retries=0 max_retries=16 should_retry=0 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 was withdrawn.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. > > > > Signed-off-by: Michal Hocko > > --- > > include/trace/events/mmflags.h | 26 ++++++++++++++++++++++++++ > > include/trace/events/oom.h | 39 +++++++++++++++++++++++++++++++++++++++ > > mm/page_alloc.c | 22 ++++++++++++++++------ > > 3 files changed, 81 insertions(+), 6 deletions(-) > > > > diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h > > index 7e4cfede873c..aa4caa6914a9 100644 > > --- a/include/trace/events/mmflags.h > > +++ b/include/trace/events/mmflags.h > > @@ -187,8 +187,32 @@ IF_HAVE_VM_SOFTDIRTY(VM_SOFTDIRTY, "softdirty" ) \ > > EM( COMPACT_NO_SUITABLE_PAGE, "no_suitable_page") \ > > EM( COMPACT_NOT_SUITABLE_ZONE, "not_suitable_zone") \ > > EMe(COMPACT_CONTENDED, "contended") > > + > > +/* High-level compaction status feedback */ > > +#define COMPACTION_FAILED 1 > > +#define COMPACTION_WITHDRAWN 2 > > +#define COMPACTION_PROGRESS 3 > > + > > +#define compact_result_to_feedback(result) \ > > +({ \ > > + enum compact_result __result = result; \ > > + (compaction_failed(__result)) ? COMPACTION_FAILED : \ > > + (compaction_withdrawn(__result)) ? COMPACTION_WITHDRAWN : COMPACTION_PROGRESS; \ > > +}) > > It seems you forgot to actually use this "function" (sorry, didn't notice > earlier) so currently it's translating enum compact_result directly into the > failed/withdrawn/progress strings, which is wrong. You are right. I've screwed while integrating the enum translation part. > The correct place for the result->feedback conversion should be > TP_fast_assign, so __entry->result should become __entry->feedback. It's too > late in TP_printk, as userspace tools (e.g. trace-cmd) won't know the > functions that compact_result_to_feedback() uses. Thanks. The follow up fix should be --- >>From 82c9064698594d694b052d3847c905e90becc7c5 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Wed, 14 Dec 2016 19:09:10 +0100 Subject: [PATCH] fold me "oom, trace: add compaction retry tracepoint" Do not forget to translate compact_result into a highlevel constants as per Vlastimil Signed-off-by: Michal Hocko --- include/trace/events/oom.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/trace/events/oom.h b/include/trace/events/oom.h index e9d690665b7a..38baeb27221a 100644 --- a/include/trace/events/oom.h +++ b/include/trace/events/oom.h @@ -94,7 +94,7 @@ TRACE_EVENT(compact_retry, TP_fast_assign( __entry->order = order; __entry->priority = priority; - __entry->result = result; + __entry->result = compact_result_to_feedback(result); __entry->retries = retries; __entry->max_retries = max_retries; __entry->ret = ret; -- 2.10.2 -- Michal Hocko SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wj0-f198.google.com (mail-wj0-f198.google.com [209.85.210.198]) by kanga.kvack.org (Postfix) with ESMTP id 1CDD36B0038 for ; Wed, 14 Dec 2016 13:11:38 -0500 (EST) Received: by mail-wj0-f198.google.com with SMTP id bk3so13380737wjc.4 for ; Wed, 14 Dec 2016 10:11:38 -0800 (PST) Received: from mail-wj0-f196.google.com (mail-wj0-f196.google.com. [209.85.210.196]) by mx.google.com with ESMTPS id h70si8451118wme.114.2016.12.14.10.11.36 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 14 Dec 2016 10:11:36 -0800 (PST) Received: by mail-wj0-f196.google.com with SMTP id he10so6183365wjc.2 for ; Wed, 14 Dec 2016 10:11:36 -0800 (PST) Date: Wed, 14 Dec 2016 19:11:34 +0100 From: Michal Hocko Subject: Re: [PATCH 3/3] oom, trace: add compaction retry tracepoint Message-ID: <20161214181133.GB16763@dhcp22.suse.cz> References: <20161214145324.26261-1-mhocko@kernel.org> <20161214145324.26261-4-mhocko@kernel.org> <60cfb7ca-fb95-7a34-bae2-9b7c49119573@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <60cfb7ca-fb95-7a34-bae2-9b7c49119573@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Vlastimil Babka Cc: Andrew Morton , David Rientjes , Johannes Weiner , linux-mm@kvack.org, LKML On Wed 14-12-16 18:28:38, Vlastimil Babka wrote: > On 12/14/2016 03:53 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. > > > > Signed-off-by: Michal Hocko > > --- > > include/trace/events/mmflags.h | 26 ++++++++++++++++++++++++++ > > include/trace/events/oom.h | 39 +++++++++++++++++++++++++++++++++++++++ > > mm/page_alloc.c | 22 ++++++++++++++++------ > > 3 files changed, 81 insertions(+), 6 deletions(-) > > > > diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h > > index 7e4cfede873c..aa4caa6914a9 100644 > > --- a/include/trace/events/mmflags.h > > +++ b/include/trace/events/mmflags.h > > @@ -187,8 +187,32 @@ IF_HAVE_VM_SOFTDIRTY(VM_SOFTDIRTY, "softdirty" ) \ > > EM( COMPACT_NO_SUITABLE_PAGE, "no_suitable_page") \ > > EM( COMPACT_NOT_SUITABLE_ZONE, "not_suitable_zone") \ > > EMe(COMPACT_CONTENDED, "contended") > > + > > +/* High-level compaction status feedback */ > > +#define COMPACTION_FAILED 1 > > +#define COMPACTION_WITHDRAWN 2 > > +#define COMPACTION_PROGRESS 3 > > + > > +#define compact_result_to_feedback(result) \ > > +({ \ > > + enum compact_result __result = result; \ > > + (compaction_failed(__result)) ? COMPACTION_FAILED : \ > > + (compaction_withdrawn(__result)) ? COMPACTION_WITHDRAWN : COMPACTION_PROGRESS; \ > > +}) > > It seems you forgot to actually use this "function" (sorry, didn't notice > earlier) so currently it's translating enum compact_result directly into the > failed/withdrawn/progress strings, which is wrong. You are right. I've screwed while integrating the enum translation part. > The correct place for the result->feedback conversion should be > TP_fast_assign, so __entry->result should become __entry->feedback. It's too > late in TP_printk, as userspace tools (e.g. trace-cmd) won't know the > functions that compact_result_to_feedback() uses. Thanks. The follow up fix should be ---