On Tue, 23 Jan 2024 18:58:26 +0100, Jan Kara wrote:
> The detection of dirty-throttled tasks in blk-wbt has been subtly broken
> since its beginning in 2016. Namely if we are doing cgroup writeback and
> the throttled task is not in the root cgroup, balance_dirty_pages() will
> set dirty_sleep for the non-root bdi_writeback structure. However
> blk-wbt checks dirty_sleep only in the root cgroup bdi_writeback
> structure. Thus detection of recently throttled tasks is not working in
> this case (we noticed this when we switched to cgroup v2 and suddently
> writeback was slow).
>
> [...]
Applied, thanks!
[1/1] blk-wbt: Fix detection of dirty-throttled tasks
commit: f814bdda774c183b0cc15ec8f3b6e7c6f4527ba5
Best regards,
--
Jens Axboe
