Re: [PATCH 3/4] blk-iocost: account zone append completions in latency stats

[Christoph Hellwig]

On Tue, Sep 08, 2026 at 10:21:34AM +0800, Tao Cui wrote:
> From: Tao Cui <cuitao@xxxxxxxxxx>
> 
> ioc_rqos_done() only accounts READ and WRITE completions, so zone
> append completions are excluded from the latency window: the vrate
> feedback loop cannot see ZA-induced latency, leaving it unable to
> respond to device saturation caused by zone appends.  Similarly,
> calc_size_vtime_cost_builtin() does not classify zone append as a
> write operation.
> 
> Charging (the cost model) and feedback (the latency window) are
> separate mechanisms, so this is not covered by the previous patch
> that prices zone appends.
> 
> Treat zone append as WRITE for both latency accounting and cost
> classification.

Can you add a blktests for this and the flush case?