From c38975c427cc3d3f6eb66a36143893be5cdf4ebd Mon Sep 17 00:00:00 2001 From: Tao Cui Date: Tue, 22 Sep 2026 12:38:55 +0800 Subject: [PATCH] blk-iocost: account zone append completions in latency stats 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. Fixes: 0512a75b98f8 ("block: Introduce REQ_OP_ZONE_APPEND") Signed-off-by: Tao Cui Reviewed-by: Christoph Hellwig Acked-by: Tejun Heo Link: https://patch.msgid.link/20260922043856.2020116-4-cui.tao@linux.dev Signed-off-by: Jens Axboe --- block/blk-iocost.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 6b262ccb6b32..9ca58cfbce86 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -2601,6 +2601,7 @@ static void calc_size_vtime_cost_builtin(struct request *rq, struct ioc *ioc, case REQ_OP_READ: *costp = pages * ioc->params.lcoefs[LCOEF_RPAGE]; break; + case REQ_OP_ZONE_APPEND: case REQ_OP_WRITE: *costp = pages * ioc->params.lcoefs[LCOEF_WPAGE]; break; @@ -2871,6 +2872,7 @@ static void ioc_rqos_done(struct rq_qos *rqos, struct request *rq) pidx = QOS_RLAT; rw = READ; break; + case REQ_OP_ZONE_APPEND: case REQ_OP_WRITE: pidx = QOS_WLAT; rw = WRITE;