From f7bc22ca0d55bdcb59e3a4a028fb811d23e53959 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 16 Jan 2026 15:46:38 +0800 Subject: nvme/io_uring: optimize IOPOLL completions for local ring context When multiple io_uring rings poll on the same NVMe queue, one ring can find completions belonging to another ring. The current code always uses task_work to handle this, but this adds overhead for the common single-ring case. This patch passes the polling io_ring_ctx through io_comp_batch's new poll_ctx field. In io_do_iopoll(), the polling ring's context is stored in iob.poll_ctx before calling the iopoll callbacks. In nvme_uring_cmd_end_io(), we now compare iob->poll_ctx with the request's owning io_ring_ctx (via io_uring_cmd_ctx_handle()). If they match (local context), we complete inline with io_uring_cmd_done32(). If they differ (remote context) or iob is NULL (non-iopoll path), we use task_work as before. This optimization eliminates task_work scheduling overhead for the common case where a ring polls and finds its own completions. ~10% IOPS improvement is observed in the following benchmark: fio/t/io_uring -b512 -d128 -c32 -s32 -p1 -F1 -O0 -P1 -u1 -n1 /dev/ng0n1 Signed-off-by: Ming Lei Reviewed-by: Kanchan Joshi Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 438c4946b6e5..251e0f538c4c 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1822,6 +1822,7 @@ struct io_comp_batch { struct rq_list req_list; bool need_ts; void (*complete)(struct io_comp_batch *); + void *poll_ctx; }; static inline bool blk_atomic_write_start_sect_aligned(sector_t sector, -- cgit v1.2.3