Re: [PATCH v5 2/3] workqueue: doc: Add a note saturating the system_wq is not permitted

From: Chen Ridong
Date: Mon Oct 07 2024 - 21:32:55 EST




On 2024/9/30 20:50, Michal Koutný wrote:
Hi.

On Fri, Sep 27, 2024 at 04:08:26PM GMT, Chen Ridong <chenridong@xxxxxxxxxxxxxxx> wrote:
How about:
Note: If something may generate works frequently, it may saturate the
system_wq and potentially lead to deadlock. It should utilize its own
dedicated workqueue rather than system wq.

It doesn't depend only on generating frequency (in Tetsuo's example with
slow works, the "high" would only be 256/s) and accurate information is
likely only empirical, thus I'd refine it further:

Note: If something may generate more than @max_active outstanding
work items (do stress test your producers), it may saturate a system
wq and potentially lead to deadlock. It should utilize its own
dedicated workqueue rather than the system wq.

(besides @max_active reference, I also changed generic system_wq to
system wq as the surrounding text seems to refer to any of the
system_*wq)

Michal

Thank you, Michal.
I took a week off.
I will update soon.

Best regards,
Ridong.