From af0a2ffef0e6d23412dd55df29f5caef8f3583f2 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Tue, 5 Nov 2024 02:12:33 +0000 Subject: [PATCH] io_uring: avoid normal tw intermediate fallback When a DEFER_TASKRUN io_uring is terminating it requeues deferred task work items as normal tw, which can further fallback to kthread execution. Avoid this extra step and always push them to the fallback kthread. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/d1cd472cec2230c66bd1c8d412a5833f0af75384.1730772720.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- io_uring/io_uring.c | 21 ++++++++++----------- io_uring/io_uring.h | 2 +- 2 files changed, 11 insertions(+), 12 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 751b9e19da6e..042a65d38d0c 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -1066,9 +1066,8 @@ struct llist_node *io_handle_tw_list(struct llist_node *node, return node; } -static __cold void io_fallback_tw(struct io_uring_task *tctx, bool sync) +static __cold void __io_fallback_tw(struct llist_node *node, bool sync) { - struct llist_node *node = llist_del_all(&tctx->task_list); struct io_ring_ctx *last_ctx = NULL; struct io_kiocb *req; @@ -1094,6 +1093,13 @@ static __cold void io_fallback_tw(struct io_uring_task *tctx, bool sync) } } +static void io_fallback_tw(struct io_uring_task *tctx, bool sync) +{ + struct llist_node *node = llist_del_all(&tctx->task_list); + + __io_fallback_tw(node, sync); +} + struct llist_node *tctx_task_work_run(struct io_uring_task *tctx, unsigned int max_entries, unsigned int *count) @@ -1247,16 +1253,9 @@ void io_req_task_work_add_remote(struct io_kiocb *req, struct io_ring_ctx *ctx, static void __cold io_move_task_work_from_local(struct io_ring_ctx *ctx) { - struct llist_node *node; + struct llist_node *node = llist_del_all(&ctx->work_llist); - node = llist_del_all(&ctx->work_llist); - while (node) { - struct io_kiocb *req = container_of(node, struct io_kiocb, - io_task_work.node); - - node = node->next; - io_req_normal_work_add(req); - } + __io_fallback_tw(node, false); } static bool io_run_local_work_continue(struct io_ring_ctx *ctx, int events, diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h index 702c8e987430..4070d4c8ef97 100644 --- a/io_uring/io_uring.h +++ b/io_uring/io_uring.h @@ -136,7 +136,7 @@ static inline void io_lockdep_assert_cq_locked(struct io_ring_ctx *ctx) * Not from an SQE, as those cannot be submitted, but via * updating tagged resources. */ - if (ctx->submitter_task->flags & PF_EXITING) + if (percpu_ref_is_dying(&ctx->refs)) lockdep_assert(current_work()); else lockdep_assert(current == ctx->submitter_task);