From: Mel Gorman <mgorman@techsingularity.net>
To: NeilBrown <neilb@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Theodore Ts'o <tytso@mit.edu>,
Andreas Dilger <adilger.kernel@dilger.ca>,
"Darrick J . Wong" <djwong@kernel.org>,
Matthew Wilcox <willy@infradead.org>,
Michal Hocko <mhocko@suse.com>,
Dave Chinner <david@fromorbit.com>,
Rik van Riel <riel@surriel.com>, Vlastimil Babka <vbabka@suse.cz>,
Johannes Weiner <hannes@cmpxchg.org>,
Jonathan Corbet <corbet@lwn.net>, Linux-MM <linux-mm@kvack.org>,
Linux-fsdevel <linux-fsdevel@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 7/8] mm/vmscan: Increase the timeout if page reclaim is not making progress
Date: Fri, 22 Oct 2021 09:14:50 +0100 [thread overview]
Message-ID: <20211022081450.GH3959@techsingularity.net> (raw)
In-Reply-To: <163486486314.17149.7181265861483962024@noble.neil.brown.name>
On Fri, Oct 22, 2021 at 12:07:43PM +1100, NeilBrown wrote:
> On Tue, 19 Oct 2021, Mel Gorman wrote:
> > Tracing of the stutterp workload showed the following delays
> >
> > 1 usect_delayed=124000 reason=VMSCAN_THROTTLE_NOPROGRESS
> > 1 usect_delayed=128000 reason=VMSCAN_THROTTLE_NOPROGRESS
> > 1 usect_delayed=176000 reason=VMSCAN_THROTTLE_NOPROGRESS
> > 1 usect_delayed=536000 reason=VMSCAN_THROTTLE_NOPROGRESS
> > 1 usect_delayed=544000 reason=VMSCAN_THROTTLE_NOPROGRESS
> > 1 usect_delayed=556000 reason=VMSCAN_THROTTLE_NOPROGRESS
> > 1 usect_delayed=624000 reason=VMSCAN_THROTTLE_NOPROGRESS
> > 1 usect_delayed=716000 reason=VMSCAN_THROTTLE_NOPROGRESS
> > 1 usect_delayed=772000 reason=VMSCAN_THROTTLE_NOPROGRESS
> > 2 usect_delayed=512000 reason=VMSCAN_THROTTLE_NOPROGRESS
> > 16 usect_delayed=120000 reason=VMSCAN_THROTTLE_NOPROGRESS
> > 53 usect_delayed=116000 reason=VMSCAN_THROTTLE_NOPROGRESS
> > 116 usect_delayed=112000 reason=VMSCAN_THROTTLE_NOPROGRESS
> > 5907 usect_delayed=108000 reason=VMSCAN_THROTTLE_NOPROGRESS
> > 71741 usect_delayed=104000 reason=VMSCAN_THROTTLE_NOPROGRESS
> >
> > All the throttling hit the full timeout and then there was wakeup delays
> > meaning that the wakeups are premature as no other reclaimer such as
> > kswapd has made progress. This patch increases the maximum timeout.
>
> Would love to see the comparable tracing results for after the patch.
>
They're in the leader. The trace figures in the changelog are the ones I
had at the time the patch was developed and I didn't keep them up to date
to reduce overall test time. At the last set of results, some throttling
was still hitting the full timeout;
[....]
843 usec_timeout=500000 usect_delayed=12000 reason=VMSCAN_THROTTLE_NOPROGRESS
1299 usec_timeout=500000 usect_delayed=104000 reason=VMSCAN_THROTTLE_NOPROGRESS
2839 usec_timeout=500000 usect_delayed=8000 reason=VMSCAN_THROTTLE_NOPROGRESS
10111 usec_timeout=500000 usect_delayed=4000 reason=VMSCAN_THROTTLE_NOPROGRESS
21492 usec_timeout=500000 usect_delayed=0 reason=VMSCAN_THROTTLE_NOPROGRESS
36441 usec_timeout=500000 usect_delayed=500000 reason=VMSCAN_THROTTLE_NOPROGRESS
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2021-10-22 8:14 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-19 9:01 [PATCH v4 0/8] Remove dependency on congestion_wait in mm/ Mel Gorman
2021-10-19 9:01 ` [PATCH 1/8] mm/vmscan: Throttle reclaim until some writeback completes if congested Mel Gorman
2021-10-19 9:01 ` [PATCH 2/8] mm/vmscan: Throttle reclaim and compaction when too may pages are isolated Mel Gorman
2021-10-19 17:12 ` Yang Shi
2021-10-19 9:01 ` [PATCH 3/8] mm/vmscan: Throttle reclaim when no progress is being made Mel Gorman
2021-10-19 9:01 ` [PATCH 4/8] mm/writeback: Throttle based on page writeback instead of congestion Mel Gorman
2021-10-19 9:01 ` [PATCH 5/8] mm/page_alloc: Remove the throttling logic from the page allocator Mel Gorman
2021-10-19 9:20 ` Vlastimil Babka
2021-10-19 9:01 ` [PATCH 6/8] mm/vmscan: Centralise timeout values for reclaim_throttle Mel Gorman
2021-10-22 1:06 ` NeilBrown
2021-10-22 8:12 ` Mel Gorman
2021-10-19 9:01 ` [PATCH 7/8] mm/vmscan: Increase the timeout if page reclaim is not making progress Mel Gorman
2021-10-22 1:07 ` NeilBrown
2021-10-22 8:14 ` Mel Gorman [this message]
2021-10-19 9:01 ` [PATCH 8/8] mm/vmscan: Delay waking of tasks throttled on NOPROGRESS Mel Gorman
2021-10-19 22:00 ` [PATCH v4 0/8] Remove dependency on congestion_wait in mm/ Andrew Morton
2021-10-20 8:44 ` Mel Gorman
2021-10-22 1:15 ` NeilBrown
2021-10-22 8:39 ` Mel Gorman
2021-10-22 11:26 ` NeilBrown
2021-10-22 13:17 ` Mel Gorman
2021-10-27 0:43 ` NeilBrown
2021-10-27 10:13 ` Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2021-10-22 14:46 [PATCH v5 " Mel Gorman
2021-10-22 14:46 ` [PATCH 7/8] mm/vmscan: Increase the timeout if page reclaim is not making progress Mel Gorman
2021-10-08 13:53 [PATCH v3 0/8] Remove dependency on congestion_wait in mm/ Mel Gorman
2021-10-08 13:53 ` [PATCH 7/8] mm/vmscan: Increase the timeout if page reclaim is not making progress Mel Gorman
2021-10-14 15:39 ` Vlastimil Babka
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