Re: [PATCH] blk-wbt: Fix detection of dirty-throttled tasks

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,