From: "NeilBrown" <neilb@suse.de>
To: "Mel Gorman" <mgorman@techsingularity.net>
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>,
"Mel Gorman" <mgorman@techsingularity.net>
Subject: Re: [PATCH 6/8] mm/vmscan: Centralise timeout values for reclaim_throttle
Date: Fri, 22 Oct 2021 12:06:13 +1100 [thread overview]
Message-ID: <163486477387.17149.7808824931340167601@noble.neil.brown.name> (raw)
In-Reply-To: <20211019090108.25501-7-mgorman@techsingularity.net>
On Tue, 19 Oct 2021, Mel Gorman wrote:
...
> + switch(reason) {
> + case VMSCAN_THROTTLE_NOPROGRESS:
> + case VMSCAN_THROTTLE_WRITEBACK:
> + timeout = HZ/10;
> +
> + if (atomic_inc_return(&pgdat->nr_writeback_throttled) == 1) {
> + WRITE_ONCE(pgdat->nr_reclaim_start,
> + node_page_state(pgdat, NR_THROTTLED_WRITTEN));
You have introduced a behaviour change that wasn't flagged in the commit
message.
Previously nr_writeback_throttled was only incremented for
VMSCAN_THROTTLE_WRITEBACK, now it is incremented for
VMSCAN_THROTTLE_NOPROGRESS as well.
Some justification would be good.
> + }
> +
> + break;
> + case VMSCAN_THROTTLE_ISOLATED:
> + timeout = HZ/50;
> + break;
> + default:
> + WARN_ON_ONCE(1);
> + timeout = HZ;
> + break;
> }
>
> prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE);
> ret = schedule_timeout(timeout);
> finish_wait(wqh, &wait);
>
> - if (acct_writeback)
> + if (reason == VMSCAN_THROTTLE_ISOLATED)
(defect) I think you want "!=" there.
While the numbers a still magic, they are now well documented and all in
one place - a definite improvement!
Thanks,
NeilBrown
next prev parent reply other threads:[~2021-10-22 1:06 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 [this message]
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
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 6/8] mm/vmscan: Centralise timeout values for reclaim_throttle 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 6/8] mm/vmscan: Centralise timeout values for reclaim_throttle Mel Gorman
2021-10-14 15:38 ` Vlastimil Babka
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