Re: [PATCH] blk-cgroup: Properly propagate the iostat update up the hierarchy

Jens Axboe
2024-05-16T02:21:16Z

On Wed, 15 May 2024 10:30:59 -0400, Waiman Long wrote:
> During a cgroup_rstat_flush() call, the lowest level of nodes are flushed
> first before their parents. Since commit 3b8cc6298724 ("blk-cgroup:
> Optimize blkcg_rstat_flush()"), iostat propagation was still done to
> the parent. Grandparent, however, may not get the iostat update if the
> parent has no blkg_iostat_set queued in its lhead lockless list.
>
> Fix this iostat propagation problem by queuing the parent's global
> blkg->iostat into one of its percpu lockless lists to make sure that
> the delta will always be propagated up to the grandparent and so on
> toward the root blkcg.
>
> [...]

Applied, thanks!

[1/1] blk-cgroup: Properly propagate the iostat update up the hierarchy
commit: 9d230c09964e6e18c8f6e4f0d41ee90eef45ec1c

Best regards,
--
Jens Axboe