From: Mike Galbraith <efault@gmx.de>
To: Alexey Avramov <hakavlad@inbox.lv>,
Mel Gorman <mgorman@techsingularity.net>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.com>, Vlastimil Babka <vbabka@suse.cz>,
Rik van Riel <riel@surriel.com>, Darrick Wong <djwong@kernel.org>,
regressions@lists.linux.dev,
Linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/1] mm: vmscan: Reduce throttling due to a failure to make progress
Date: Sun, 28 Nov 2021 11:00:59 +0100 [thread overview]
Message-ID: <252cd5acd9bf6588ec87ce02884925c737b6a8b7.camel@gmx.de> (raw)
In-Reply-To: <20211128042635.543a2d04@mail.inbox.lv>
On Sun, 2021-11-28 at 04:26 +0900, Alexey Avramov wrote:
> I will present the results of the new tests here.
>
> TLDR;
> =====
> No one Mel's patch doesn't prevent stalls in my tests.
Seems there may be a problem with the THROTTLE_WRITEBACK bits..
> $ for i in {1..10}; do tail /dev/zero; done
> -- 1. with noswap
..because the bandaid below (made of 8cd7c588 shards) on top of Mel's
last pulled that one-liner's very pointy fangs.
---
mm/backing-dev.c | 5 +++++
mm/vmscan.c | 8 +++++++-
2 files changed, 12 insertions(+), 1 deletion(-)
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -1055,3 +1055,8 @@ long congestion_wait(int sync, long time
return ret;
}
EXPORT_SYMBOL(congestion_wait);
+
+int async_bdi_congested(void)
+{
+ return atomic_read(&nr_wb_congested[BLK_RW_ASYNC]) != 0;
+}
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1021,6 +1021,8 @@ static void handle_write_error(struct ad
unlock_page(page);
}
+extern int async_bdi_congested(void);
+
void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason)
{
wait_queue_head_t *wqh = &pgdat->reclaim_wait[reason];
@@ -1048,6 +1050,10 @@ void reclaim_throttle(pg_data_t *pgdat,
*/
switch(reason) {
case VMSCAN_THROTTLE_WRITEBACK:
+ if (!async_bdi_congested()) {
+ cond_resched();
+ return;
+ }
timeout = HZ/10;
if (atomic_inc_return(&pgdat->nr_writeback_throttled) == 1) {
@@ -1079,7 +1085,7 @@ void reclaim_throttle(pg_data_t *pgdat,
}
prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE);
- ret = schedule_timeout(timeout);
+ ret = io_schedule_timeout(timeout);
finish_wait(wqh, &wait);
if (reason == VMSCAN_THROTTLE_WRITEBACK)
next prev parent reply other threads:[~2021-11-28 10:03 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-25 15:18 [PATCH 1/1] mm: vmscan: Reduce throttling due to a failure to make progress Mel Gorman
2021-11-26 10:14 ` Vlastimil Babka
2021-11-26 10:26 ` Mike Galbraith
2021-11-26 16:12 ` Alexey Avramov
2021-11-26 16:52 ` Mel Gorman
2021-11-27 19:26 ` Alexey Avramov
2021-11-28 10:00 ` Mike Galbraith [this message]
2021-11-28 11:39 ` Mike Galbraith
2021-11-28 12:35 ` Mike Galbraith
2021-11-28 18:38 ` Mike Galbraith
2021-11-28 11:58 ` Alexey Avramov
2021-11-29 8:26 ` Mel Gorman
2021-11-29 15:01 ` Mel Gorman
2021-11-30 10:14 ` Mike Galbraith
2021-11-30 11:22 ` Mel Gorman
2021-11-30 12:00 ` Mike Galbraith
2021-11-30 12:51 ` Mike Galbraith
2021-11-30 13:09 ` Mel Gorman
2021-12-01 4:32 ` Mike Galbraith
2021-11-30 16:03 ` Alexey Avramov
2021-11-30 17:27 ` Mel Gorman
2021-11-30 17:59 ` Mike Galbraith
2021-12-01 13:01 ` Mel Gorman
2021-12-01 13:52 ` Mike Galbraith
2021-12-01 15:06 ` Mel Gorman
2021-11-30 18:38 ` Alexey Avramov
2021-12-01 14:00 ` Mel Gorman
2021-12-01 17:29 ` Darrick J. Wong
2021-12-02 9:43 ` Mel Gorman
2021-12-02 16:09 ` Darrick J. Wong
2021-12-02 3:11 ` Mike Galbraith
2021-12-02 10:13 ` Mel Gorman
2021-12-02 10:51 ` Mike Galbraith
2021-12-02 11:42 ` Alexey Avramov
2021-12-02 12:14 ` Alexey Avramov
2021-12-02 12:15 ` Mel Gorman
2021-12-02 12:22 ` Alexey Avramov
2021-12-02 13:18 Mel Gorman
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