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From: Jens Axboe <axboe@kernel.dk>
To: Tejun Heo <tj@kernel.org>, Josef Bacik <josef@toxicpanda.com>, 
 Waiman Long <longman@redhat.com>
Cc: cgroups@vger.kernel.org, linux-block@vger.kernel.org, 
 linux-kernel@vger.kernel.org, Dan Schatzberg <schatzberg.dan@gmail.com>, 
 Ming Lei <ming.lei@redhat.com>
In-Reply-To: <20240515143059.276677-1-longman@redhat.com>
References: <20240515143059.276677-1-longman@redhat.com>
Subject: Re: [PATCH] blk-cgroup: Properly propagate the iostat update up
 the hierarchy
Message-Id: <171582607425.11025.1197820625337989209.b4-ty@kernel.dk>
Date: Wed, 15 May 2024 20:21:14 -0600
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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