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From: no-reply@sashiko.virtuozzo.com
To: andrey.zhadchenko@virtuozzo.com, "Denis V. Lunev" <den@openvz.org>
Cc: devel@openvz.org
Subject: Re: [Devel] [PATCH hci-8.1 2/4] dm-ploop: fix a lost wakeup of the ploop_allocator() thread
Date: Tue, 3 Nov 2026 08:39:45 +0000	[thread overview]
Message-ID: <010701a1a0907bb3-12ba536b-9457-4862-ab09-edc188c54df5-000000@eu-central-1.amazonses.com> (raw)
In-Reply-To: <20261103083642.130885-3-den@openvz.org>

> From: Denis V. Lunev <den@openvz.org>
> 
> ploop_allocator() tests prealloc_size and only then sets itself
> TASK_INTERRUPTIBLE before schedule(). A request that lands between the
> two finds the thread still running, so wake_up_process() does nothing,
> and the thread goes to sleep with the request pending. A pio whose
> cluster is past the end of the top delta then waits in
> ploop_allocate_cluster() until some later request wakes the thread. The
> dispatcher waits for every runner to go idle before it hands out more
> work, so the whole device stalls, and an idle device has no later
> request.
> 
> Set the task state before testing prealloc_size.
> 
> Fixes: cf489cf22cd5 ("dm-ploop: make filespace preallocations async")
> Reported-by: Konstantin Khorenko <khorenko@virtuozzo.com>
> https://virtuozzo.atlassian.net/browse/VSTOR-152984
> Feature: dm-ploop: ploop target driver
> Signed-off-by: Denis V. Lunev <den@openvz.org>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.vzint.dev/#/patchset/20261103083642.130885-1-den@openvz.org?part=2


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  reply	other threads:[~2026-11-03  8:41 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-03  8:36 [Devel] [PATCH hci-8.1 0/4] dm-ploop: fix the pio submission stop around cmds Denis V. Lunev
2026-11-03  8:36 ` [Devel] [PATCH hci-8.1 1/4] dm-ploop: fix pio submission racing with the suspend and resume of a cmd Denis V. Lunev
2026-11-03  8:40   ` no-reply
2026-11-04 17:14   ` Konstantin Khorenko
2026-11-03  8:36 ` [Devel] [PATCH hci-8.1 2/4] dm-ploop: fix a lost wakeup of the ploop_allocator() thread Denis V. Lunev
2026-11-03  8:39   ` no-reply [this message]
2026-11-04 17:14   ` Konstantin Khorenko
2026-11-03  8:36 ` [Devel] [PATCH hci-8.1 3/4] dm-ploop: wait for the ploop_allocator() thread before changing deltas[] Denis V. Lunev
2026-11-03  8:42   ` no-reply
2026-11-04 17:14   ` Konstantin Khorenko
2026-11-03  8:36 ` [Devel] [PATCH hci-8.1 4/4] dm-ploop: fix a failed cluster copy on grow leaving the BAT page busy Denis V. Lunev
2026-11-03  8:42   ` no-reply
2026-11-04 17:14   ` Konstantin Khorenko
2026-11-04 13:24 ` [Devel] [PATCH hci-8.1 0/4] dm-ploop: fix the pio submission stop around cmds Andrey Zhadchenko
2026-11-04 17:14 ` Konstantin Khorenko

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