From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751336AbbAMHPk (ORCPT ); Tue, 13 Jan 2015 02:15:40 -0500 Received: from lgeamrelo04.lge.com ([156.147.1.127]:48035 "EHLO lgeamrelo04.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751052AbbAMHPj (ORCPT ); Tue, 13 Jan 2015 02:15:39 -0500 X-Original-SENDERIP: 10.177.222.153 X-Original-MAILFROM: iamjoonsoo.kim@lge.com Date: Tue, 13 Jan 2015 16:16:05 +0900 From: Joonsoo Kim To: Vlastimil Babka Cc: Andrew Morton , Mel Gorman , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 4/5] mm/compaction: more trace to understand when/why compaction start/finish Message-ID: <20150113071605.GA29898@js1304-P5Q-DELUXE> References: <1421050875-26332-1-git-send-email-iamjoonsoo.kim@lge.com> <1421050875-26332-4-git-send-email-iamjoonsoo.kim@lge.com> <54B3EE11.3040303@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54B3EE11.3040303@suse.cz> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 12, 2015 at 04:53:53PM +0100, Vlastimil Babka wrote: > On 01/12/2015 09:21 AM, Joonsoo Kim wrote: > > It is not well analyzed that when/why compaction start/finish or not. With > > these new tracepoints, we can know much more about start/finish reason of > > compaction. I can find following bug with these tracepoint. > > > > http://www.spinics.net/lists/linux-mm/msg81582.html > > > > Signed-off-by: Joonsoo Kim > > --- > > include/linux/compaction.h | 3 ++ > > include/trace/events/compaction.h | 94 +++++++++++++++++++++++++++++++++++++ > > mm/compaction.c | 41 ++++++++++++++-- > > 3 files changed, 134 insertions(+), 4 deletions(-) > > > > diff --git a/include/linux/compaction.h b/include/linux/compaction.h > > index a9547b6..d82181a 100644 > > --- a/include/linux/compaction.h > > +++ b/include/linux/compaction.h > > @@ -12,6 +12,9 @@ > > #define COMPACT_PARTIAL 3 > > /* The full zone was compacted */ > > #define COMPACT_COMPLETE 4 > > +/* For more detailed tracepoint output */ > > +#define COMPACT_NO_SUITABLE_PAGE 5 > > +#define COMPACT_NOT_SUITABLE_ZONE 6 > > /* When adding new state, please change compaction_status_string, too */ > > > > /* Used to signal whether compaction detected need_sched() or lock contention */ > > diff --git a/include/trace/events/compaction.h b/include/trace/events/compaction.h > > index 139020b..839dd4f 100644 > > --- a/include/trace/events/compaction.h > > +++ b/include/trace/events/compaction.h > > @@ -164,6 +164,100 @@ TRACE_EVENT(mm_compaction_end, > > compaction_status_string[__entry->status]) > > ); > > > > +TRACE_EVENT(mm_compaction_try_to_compact_pages, > > + > > + TP_PROTO( > > + int order, > > + gfp_t gfp_mask, > > + enum migrate_mode mode, > > + int alloc_flags, > > + int classzone_idx), > > I wonder if alloc_flags and classzone_idx is particularly useful. It affects the > watermark checks, but those are a bit of blackbox anyway. Yes, I think so. How about printing gfp_flag rather than these? It would tell us migratetype and other information so would be useful. Thanks.