Re: [PATCH 0/4] block: drain per-cpu latency stats over possible CPUs

Jens Axboe <[email protected]> Mon, 03 Aug 2026 20:17:10 -0600
Newsgroups org.kernel.vger.linux-block,org.kernel.vger.cgroups,org.kernel.vger.linux-kernel
Message-ID <178580983082.518281.5058620574595097621.b4-ty@b4>
On Mon, 20 Jul 2026 17:37:22 +0800, Tao Cui wrote:
> Several block-layer latency statistics accumulate samples in per-cpu
> buckets and drain them periodically -- in timer callbacks, or at each
> check / reporting site -- using for_each_online_cpu().  When a CPU that
> holds pending samples is taken offline, that bucket is skipped during
> the drain: the samples are neither accumulated into the current window
> nor, where the drain also resets, cleared.  They sit in the bucket until
> the CPU is brought back online, at which point they are flushed into
> whatever window happens to be running.
> 
> [...]

Applied, thanks!

[1/4] block/blk-stat: drain per-cpu callback stats over possible CPUs
      (no commit info)
[2/4] block/blk-iolatency: account per-cpu latency stats over possible CPUs
      (no commit info)
[3/4] block/blk-iocost: collect per-cpu latency stats over possible CPUs
      (no commit info)
[4/4] block/kyber-iosched: flush per-cpu latency buckets over possible CPUs
      (no commit info)

Best regards,
-- 
Jens Axboe