From: Tejun Heo <tj@kernel.org>
To: torvalds@linux-foundation.org, mpatocka@redhat.com,
Lai Jiangshan <jiangshanlai@gmail.com>
Cc: linux-kernel@vger.kernel.org, dm-devel@lists.linux.dev,
msnitzer@redhat.com, ignat@cloudflare.com, damien.lemoal@wdc.com,
houtao1@huawei.com, peterz@infradead.org, mingo@kernel.org,
netdev@vger.kernel.org, allen.lkml@gmail.com,
kernel-team@meta.com
Subject: Re: [PATCHSET wq/for-6.9] workqueue: Implement BH workqueue and convert several tasklet users
Date: Mon, 29 Jan 2024 23:22:19 -1000 [thread overview]
Message-ID: <Zbi_y9w6ze7qfxQ2@slm.duckdns.org> (raw)
In-Reply-To: <20240130091300.2968534-1-tj@kernel.org>
Oops, forgot to cc Lai.
On Mon, Jan 29, 2024 at 11:11:47PM -1000, Tejun Heo wrote:
> Hello,
>
> The only generic interface to execute asynchronously in the BH context is
> tasklet; however, it's marked deprecated and has some design flaws such as
> the execution code accessing the tasklet item after the execution is
> complete which can lead to subtle use-after-free in certain usage scenarios
> and less-developed flush and cancel mechanisms.
>
> Mikulas Patocka recently reported that dm-crypt and dm-crypt are affected by
> the access-after-completion issue and suggested adding TASKLET_STATE_ONESHOT
> flag which selectively removes post-completion access while significantly
> limiting how the tasklet can be used in the following thread:
>
> http://lkml.kernel.org/r/82b964f0-c2c8-a2c6-5b1f-f3145dc2c8e5@redhat.com
>
> Linus didn't like the approach and suggested extending workqueue to support
> execution from atomic context:
>
> http://lkml.kernel.org/r/CAHk-=wjDW53w4-YcSmgKC5RruiRLHmJ1sXeYdp_ZgVoBw=5byA@mail.gmail.com
>
> As suggested, this patchset implements BH workqueues which are like regular
> workqueues but executes work items in the BH (softirq) context and converts
> several tasklet users.
Lai, the patchset is at:
http://lkml.kernel.org/r/20240130091300.2968534-1-tj@kernel.org
I'd really appreciate if you can take a look.
Thanks.
--
tejun
next prev parent reply other threads:[~2024-01-30 9:22 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-30 9:11 [PATCHSET wq/for-6.9] workqueue: Implement BH workqueue and convert several tasklet users Tejun Heo
2024-01-30 9:11 ` [PATCH 1/8] workqueue: Update lock debugging code Tejun Heo
2024-01-30 9:11 ` [PATCH 2/8] workqueue: Factor out init_cpu_worker_pool() Tejun Heo
2024-01-30 9:11 ` [PATCH 3/8] workqueue: Implement BH workqueues to eventually replace tasklets Tejun Heo
2024-01-30 17:25 ` Linus Torvalds
2024-02-01 11:02 ` Lai Jiangshan
2024-02-01 21:47 ` Tejun Heo
2024-02-02 1:15 ` [PATCH v2 " Tejun Heo
2024-02-04 2:20 ` Lai Jiangshan
2024-02-04 21:29 ` [PATCH v3 " Tejun Heo
2024-02-05 4:48 ` Hillf Danton
2024-02-05 17:47 ` Tejun Heo
2024-02-26 2:00 ` Boqun Feng
2024-02-26 18:47 ` Tejun Heo
2024-02-27 1:38 ` [PATCH for-6.9] workqueue: Drain BH work items on hot-unplugged CPUs Tejun Heo
2024-02-29 20:37 ` Tejun Heo
2024-02-29 21:07 ` Boqun Feng
2024-01-30 9:11 ` [PATCH 4/8] backtracetest: Convert from tasklet to BH workqueue Tejun Heo
2024-01-30 9:11 ` [PATCH 5/8] usb: core: hcd: " Tejun Heo
2024-01-30 16:38 ` Greg Kroah-Hartman
2024-02-20 17:25 ` Davidlohr Bueso
2024-02-20 17:55 ` Linus Torvalds
2024-02-20 18:19 ` Tejun Heo
2024-02-20 19:36 ` Davidlohr Bueso
2024-01-30 9:11 ` [PATCH 6/8] net: tcp: tsq: " Tejun Heo
2024-02-16 5:31 ` Tejun Heo
2024-02-16 8:23 ` Eric Dumazet
2024-02-16 15:52 ` David Wei
2024-02-16 16:24 ` Tejun Heo
2024-01-30 9:11 ` [PATCH 7/8] dm-crypt: " Tejun Heo
2024-01-30 10:46 ` Sebastian Andrzej Siewior
2024-01-30 15:53 ` Tejun Heo
2024-01-31 21:23 ` Mikulas Patocka
2024-01-30 9:11 ` [PATCH 8/8] dm-verity: " Tejun Heo
2024-01-31 21:19 ` Mikulas Patocka
2024-01-31 21:32 ` Tejun Heo
2024-01-31 22:02 ` Mikulas Patocka
2024-01-31 23:19 ` Linus Torvalds
2024-02-01 0:04 ` Tejun Heo
2024-02-01 0:19 ` Mike Snitzer
2024-02-20 19:44 ` Mike Snitzer
2024-02-20 20:05 ` Tejun Heo
2024-02-22 21:24 ` Mike Snitzer
2024-02-23 17:22 ` Tejun Heo
2024-02-01 0:07 ` Mike Snitzer
2024-01-30 9:22 ` Tejun Heo [this message]
2024-01-30 10:20 ` [PATCHSET wq/for-6.9] workqueue: Implement BH workqueue and convert several tasklet users Sebastian Andrzej Siewior
2024-01-30 15:50 ` Tejun Heo
2024-01-30 23:37 ` Allen
2024-02-04 21:33 ` Tejun Heo
2024-02-05 20:50 ` Allen
2024-02-05 21:12 ` Tejun Heo
2024-02-05 21:31 ` Allen
2024-02-07 19:02 ` Allen
2024-02-08 16:56 ` Tejun Heo
2024-02-08 19:07 ` Allen
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