From: Michal Hocko <mhocko@kernel.org>
To: Minchan Kim <minchan@kernel.org>
Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
Mel Gorman <mgorman@suse.de>,
Johannes Weiner <hannes@cmpxchg.org>,
Vlastimil Babka <vbabka@suse.cz>, Rik van Riel <riel@redhat.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 4/7] mm, vmscan: show LRU name in mm_vmscan_lru_isolate tracepoint
Date: Thu, 29 Dec 2016 08:56:49 +0100 [thread overview]
Message-ID: <20161229075649.GB29208@dhcp22.suse.cz> (raw)
In-Reply-To: <20161229060204.GC1815@bbox>
On Thu 29-12-16 15:02:04, Minchan Kim wrote:
> On Wed, Dec 28, 2016 at 04:30:29PM +0100, Michal Hocko wrote:
> > From: Michal Hocko <mhocko@suse.com>
> >
> > mm_vmscan_lru_isolate currently prints only whether the LRU we isolate
> > from is file or anonymous but we do not know which LRU this is. It is
> > useful to know whether the list is file or anonymous as well. Change
> > the tracepoint to show symbolic names of the lru rather.
> >
> > Signed-off-by: Michal Hocko <mhocko@suse.com>
>
> Not exactly same with this but idea is almost same.
> I used almost same tracepoint to investigate agging(i.e., deactivating) problem
> in 32b kernel with node-lru.
> It was enough. Namely, I didn't need tracepoint in shrink_active_list like your
> first patch.
> Your first patch is more straightforwad and information. But as you introduced
> this patch, I want to ask in here.
> Isn't it enough with this patch without your first one to find a such problem?
I assume this should be a reply to
http://lkml.kernel.org/r/20161228153032.10821-8-mhocko@kernel.org, right?
And you are right that for the particular problem it was enough to have
a tracepoint inside inactive_list_is_low and shrink_active_list one
wasn't really needed. On the other hand aging issues are really hard to
debug as well and so I think that both are useful. The first one tell us
_why_ we do aging while the later _how_ we do that.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2016-12-29 7:57 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-28 15:30 [PATCH 0/7] vm, vmscan: enahance vmscan tracepoints Michal Hocko
2016-12-28 15:30 ` [PATCH 1/7] mm, vmscan: remove unused mm_vmscan_memcg_isolate Michal Hocko
2016-12-29 7:33 ` Hillf Danton
2016-12-28 15:30 ` [PATCH 2/7] mm, vmscan: add active list aging tracepoint Michal Hocko
2016-12-29 5:33 ` Minchan Kim
2016-12-29 7:52 ` Michal Hocko
2016-12-30 1:48 ` Minchan Kim
2016-12-30 9:26 ` Michal Hocko
2016-12-30 9:38 ` Hillf Danton
2016-12-30 16:04 ` Minchan Kim
2016-12-30 16:37 ` Michal Hocko
2016-12-30 17:30 ` Michal Hocko
2017-01-03 5:03 ` Minchan Kim
2017-01-03 8:21 ` Michal Hocko
2017-01-04 5:07 ` Minchan Kim
2017-01-04 7:28 ` Vlastimil Babka
2017-01-04 7:50 ` Michal Hocko
2016-12-29 7:44 ` Hillf Danton
2016-12-28 15:30 ` [PATCH 3/7] mm, vmscan: show the number of skipped pages in mm_vmscan_lru_isolate Michal Hocko
2016-12-29 5:53 ` Minchan Kim
2016-12-29 7:49 ` Hillf Danton
2017-01-03 17:21 ` Vlastimil Babka
2017-01-03 20:43 ` Michal Hocko
2016-12-28 15:30 ` [PATCH 4/7] mm, vmscan: show LRU name in mm_vmscan_lru_isolate tracepoint Michal Hocko
2016-12-28 15:50 ` Nikolay Borisov
2016-12-28 16:00 ` Michal Hocko
2016-12-28 16:40 ` Nikolay Borisov
2016-12-28 16:49 ` Michal Hocko
2016-12-29 6:02 ` Minchan Kim
2016-12-29 7:56 ` Michal Hocko [this message]
2016-12-30 1:56 ` Minchan Kim
2016-12-30 9:33 ` Michal Hocko
2016-12-29 7:53 ` Hillf Danton
2017-01-03 17:08 ` Vlastimil Babka
2017-01-03 20:47 ` Michal Hocko
2017-01-03 20:52 ` Michal Hocko
2017-01-03 21:24 ` Michal Hocko
2017-01-03 21:40 ` Vlastimil Babka
2017-01-03 21:48 ` Michal Hocko
2016-12-28 15:30 ` [PATCH 5/7] mm, vmscan: extract shrink_page_list reclaim counters into a struct Michal Hocko
2016-12-29 8:00 ` Hillf Danton
2016-12-28 15:30 ` [PATCH 6/7] mm, vmscan: enhance mm_vmscan_lru_shrink_inactive tracepoint Michal Hocko
2016-12-29 8:05 ` Hillf Danton
2016-12-28 15:30 ` [PATCH 7/7] mm, vmscan: add mm_vmscan_inactive_list_is_low tracepoint Michal Hocko
2016-12-29 8:19 ` Hillf Danton
2016-12-30 9:11 ` [PATCH 0/7] vm, vmscan: enahance vmscan tracepoints Mel Gorman
2016-12-30 9:36 ` Michal Hocko
2016-12-30 10:20 ` Mel Gorman
2017-01-04 10:19 [PATCH 0/7 v2] " Michal Hocko
2017-01-04 10:19 ` [PATCH 4/7] mm, vmscan: show LRU name in mm_vmscan_lru_isolate tracepoint Michal Hocko
2017-01-05 6:04 ` Minchan Kim
2017-01-05 10:16 ` Michal Hocko
2017-01-05 14:56 ` Mel Gorman
2017-01-05 15:17 ` Michal Hocko
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