From: Christoph Hellwig <hch@infradead.org>
To: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <dlemoal@kernel.org>, Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org
Subject: Re: [PATCH 4/8] block: improve disk_zone_wplug_schedule_bio_work()
Date: Tue, 24 Feb 2026 07:08:21 -0800 [thread overview]
Message-ID: <aZ2-5axIKqUVAc4A@infradead.org> (raw)
In-Reply-To: <f52cc220-5a31-473d-b255-3320be90766e@suse.de>
On Tue, Feb 24, 2026 at 04:00:17PM +0100, Hannes Reinecke wrote:
> But then we deadlock.
> If a lock is held when calling queue_work() and the workqueue function
> is calling spin_lock() on the _same_ lock _and_ we are scheduled on
> the _same_ CPU (remember single-core systems ?) we deadlock.
You very obviously can't context switch to a separate thread when
holding a spinlock.
Note that I particularly like this pattern. I'd much rather just
increment the reference and drop it when we did not schedule the
work, this is not a super hot path that needs crazy optimizations,
and that would have avoided this bike shedding discussion.
next prev parent reply other threads:[~2026-02-24 15:08 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-21 0:44 [PATCH 0/8] Improve zoned (SMR) HDD write throughput Damien Le Moal
2026-02-21 0:44 ` [PATCH 1/8] block: fix zone write plug removal Damien Le Moal
2026-02-23 11:56 ` Hannes Reinecke
2026-02-23 19:30 ` Bart Van Assche
2026-02-23 20:21 ` Bart Van Assche
2026-02-24 1:57 ` Damien Le Moal
2026-02-21 0:44 ` [PATCH 2/8] block: remove BLK_ZONE_WPLUG_UNHASHED Damien Le Moal
2026-02-23 11:48 ` Hannes Reinecke
2026-02-24 2:04 ` Damien Le Moal
2026-02-21 0:44 ` [PATCH 3/8] block: remove disk_zone_is_full() Damien Le Moal
2026-02-23 11:56 ` Hannes Reinecke
2026-02-24 13:15 ` Johannes Thumshirn
2026-02-21 0:44 ` [PATCH 4/8] block: improve disk_zone_wplug_schedule_bio_work() Damien Le Moal
2026-02-23 11:59 ` Hannes Reinecke
2026-02-23 18:56 ` Bart Van Assche
2026-02-24 2:03 ` Damien Le Moal
2026-02-24 15:00 ` Hannes Reinecke
2026-02-24 15:08 ` Christoph Hellwig [this message]
2026-02-24 13:18 ` Johannes Thumshirn
2026-02-21 0:44 ` [PATCH 5/8] block: rename struct gendisk zone_wplugs_lock field Damien Le Moal
2026-02-23 12:00 ` Hannes Reinecke
2026-02-24 13:19 ` Johannes Thumshirn
2026-02-21 0:44 ` [PATCH 6/8] block: allow submitting all zone writes from a single context Damien Le Moal
2026-02-23 12:07 ` Hannes Reinecke
2026-02-24 2:00 ` Damien Le Moal
2026-02-21 0:44 ` [PATCH 7/8] block: default to QD=1 writes for blk-mq rotational zoned devices Damien Le Moal
2026-02-23 12:07 ` Hannes Reinecke
2026-02-21 0:44 ` [PATCH 8/8] Documentation: ABI: stable: document the zoned_qd1_writes attribute Damien Le Moal
2026-02-23 12:07 ` Hannes Reinecke
2026-02-23 17:03 ` [PATCH 0/8] Improve zoned (SMR) HDD write throughput Bart Van Assche
2026-02-24 1:07 ` Damien Le Moal
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=aZ2-5axIKqUVAc4A@infradead.org \
--to=hch@infradead.org \
--cc=axboe@kernel.dk \
--cc=dlemoal@kernel.org \
--cc=hare@suse.de \
--cc=linux-block@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox