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

On Tue, Sep 08, 2026 at 10:21:34AM +0800, Tao Cui wrote:

From: Tao Cui <redacted>

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?