From e318ecb8d5c90ec5d2045407e621823ce4a704c7 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 7 May 2024 14:23:49 +0800 Subject: [PATCH] io_uring: use private workqueue for exit work stable inclusion from stable-v6.6.26 commit 6b9d49bcd97bfe2eed9ee69014fd977ed0d6b27d bugzilla: https://gitee.com/openeuler/kernel/issues/I9MPZ8 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6b9d49bcd97bfe2eed9ee69014fd977ed0d6b27d -------------------------------- commit 73eaa2b583493b680c6f426531d6736c39643bfb upstream. Rather than use the system unbound event workqueue, use an io_uring specific one. This avoids dependencies with the tty, which also uses the system_unbound_wq, and issues flushes of said workqueue from inside its poll handling. Cc: stable@vger.kernel.org Reported-by: Rasmus Karlsson Tested-by: Rasmus Karlsson Tested-by: Iskren Chernev Link: https://github.com/axboe/liburing/issues/1113 Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman Signed-off-by: ZhangPeng --- io_uring/io_uring.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 5648d45665d75..0ff651d5e6524 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -148,6 +148,7 @@ static bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx, static void io_queue_sqe(struct io_kiocb *req); struct kmem_cache *req_cachep; +static struct workqueue_struct *iou_wq __ro_after_init; static int __read_mostly sysctl_io_uring_disabled; static int __read_mostly sysctl_io_uring_group = -1; @@ -3183,7 +3184,7 @@ static __cold void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) * noise and overhead, there's no discernable change in runtime * over using system_wq. */ - queue_work(system_unbound_wq, &ctx->exit_work); + queue_work(iou_wq, &ctx->exit_work); } static int io_uring_release(struct inode *inode, struct file *file) @@ -4667,6 +4668,8 @@ static int __init io_uring_init(void) offsetof(struct io_kiocb, cmd.data), sizeof_field(struct io_kiocb, cmd.data), NULL); + iou_wq = alloc_workqueue("iou_exit", WQ_UNBOUND, 64); + #ifdef CONFIG_SYSCTL register_sysctl_init("kernel", kernel_io_uring_disabled_table); #endif