From: Tejun Heo <tj@kernel.org>
To: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: torvalds@linux-foundation.org, linux-kernel@vger.kernel.org,
allen.lkml@gmail.com, kernel-team@meta.com
Subject: Re: [PATCH 12/17] workqueue: Implement disable/enable for (delayed) work items
Date: Tue, 20 Feb 2024 08:38:02 -1000 [thread overview]
Message-ID: <ZdTxisk3zp_eXDVb@slm.duckdns.org> (raw)
In-Reply-To: <CAJhGHyCOgrU9TC9o97LpvAEL2p+Dgt=uN0mo01Gr7HadVSD-Ag@mail.gmail.com>
Hello,
On Tue, Feb 20, 2024 at 03:22:26PM +0800, Lai Jiangshan wrote:
> > - A work item carries 10bit disable count in work->data while not queued.
> > The access to the count is synchronized by the PENDING bit like all other
> > parts of work->data.
>
> It is 16bit disable count in the code.
Fixed.
> It misses the same handling at queue_work_node() and queue_rcu_work().
Oops, fixed queued_work_node() but I don't think the latter is an issue
given that calling work interface functions in the embedded work is not
supported and rcu_work can't even be canceled.
I'm not quite sure flush_delayed_work() is safe. Will think more about that.
> But it is bad idea to cancel or disable rcu work since it can be possibly
> in the rcu's waiting list.
Yeah, this isn't currently supported. If we want to add this, we'd have to
have a mechanism to shoot it down from RCU's pending list.
Thanks.
--
tejun
next prev parent reply other threads:[~2024-02-20 18:38 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-16 18:04 [PATCHSET wq/for-6.9,6.10] workqueue: Implement disable/enable_work() Tejun Heo
2024-02-16 18:04 ` [PATCH 01/17] workqueue: Cosmetic changes Tejun Heo
2024-02-16 18:04 ` [PATCH 02/17] workqueue: Use rcu_read_lock_any_held() instead of rcu_read_lock_held() Tejun Heo
2024-02-16 18:04 ` [PATCH 03/17] workqueue: Rename __cancel_work_timer() to __cancel_timer_sync() Tejun Heo
2024-02-16 18:04 ` [PATCH 04/17] workqueue: Reorganize flush and cancel[_sync] functions Tejun Heo
2024-02-16 18:04 ` [PATCH 05/17] workqueue: Use variable name irq_flags for saving local irq flags Tejun Heo
2024-02-16 18:04 ` [PATCH 06/17] workqueue: Introduce work_cancel_flags Tejun Heo
2024-02-16 18:04 ` [PATCH 07/17] workqueue: Clean up enum work_bits and related constants Tejun Heo
2024-02-16 18:04 ` [PATCH 08/17] workqueue: Factor out work_grab_pending() from __cancel_work_sync() Tejun Heo
2024-02-16 18:04 ` [PATCH 09/17] workqueue: Remove clear_work_data() Tejun Heo
2024-02-16 18:04 ` [PATCH 10/17] workqueue: Make @flags handling consistent across set_work_data() and friends Tejun Heo
2024-02-16 18:04 ` [PATCH 11/17] workqueue: Preserve OFFQ bits in cancel[_sync] paths Tejun Heo
2024-02-16 18:04 ` [PATCH 12/17] workqueue: Implement disable/enable for (delayed) work items Tejun Heo
2024-02-20 7:22 ` Lai Jiangshan
2024-02-20 18:38 ` Tejun Heo [this message]
2024-02-21 2:54 ` Lai Jiangshan
2024-02-21 5:47 ` Tejun Heo
2024-02-26 3:42 ` Boqun Feng
2024-02-26 18:30 ` Tejun Heo
2024-02-16 18:04 ` [PATCH 13/17] workqueue: Remove WORK_OFFQ_CANCELING Tejun Heo
2024-02-20 7:23 ` Lai Jiangshan
2024-02-20 18:53 ` Tejun Heo
2024-02-16 18:04 ` [PATCH 14/17] workqueue: Remember whether a work item was on a BH workqueue Tejun Heo
2024-02-16 18:04 ` [PATCH 15/17] workqueue: Update how start_flush_work() is called Tejun Heo
2024-02-16 18:04 ` [PATCH 16/17] workqueue: Allow cancel_work_sync() and disable_work() from atomic contexts on BH work items Tejun Heo
2024-02-20 7:33 ` Lai Jiangshan
2024-02-20 20:01 ` Tejun Heo
2024-02-16 18:04 ` [PATCH 17/17] r8152: Convert from tasklet to BH workqueue Tejun Heo
2024-02-20 17:33 ` [PATCHSET wq/for-6.9,6.10] workqueue: Implement disable/enable_work() Allen
2024-02-20 20:25 ` Tejun Heo
2024-02-20 21:38 ` Allen
2024-02-22 20:26 ` Allen
2024-02-26 18:38 ` Tejun Heo
2024-02-27 17:56 ` Allen
2024-02-21 2:39 ` Lai Jiangshan
2024-02-21 5:39 ` Tejun Heo
2024-02-21 17:03 ` Allen
2024-02-25 17:40 ` Kees Cook
2024-02-26 17:30 ` Allen
2024-02-26 18:30 ` Tejun Heo
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