{"id":2196349,"url":"http://patchwork.ozlabs.org/api/1.0/patches/2196349/?format=json","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/1.0/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20260213143225.161043-3-axboe@kernel.dk>","date":"2026-02-13T14:26:37","name":"[2/2] fdmon-io_uring: check CQ ring directly in gsource_check","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"4f23db7237a9ec78ee455197caccab5da17dd0e5","submitter":{"id":4515,"url":"http://patchwork.ozlabs.org/api/1.0/people/4515/?format=json","name":"Jens Axboe","email":"axboe@kernel.dk"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260213143225.161043-3-axboe@kernel.dk/mbox/","series":[{"id":492105,"url":"http://patchwork.ozlabs.org/api/1.0/series/492105/?format=json","date":"2026-02-13T14:26:37","name":"io_uring fixes","version":1,"mbox":"http://patchwork.ozlabs.org/series/492105/mbox/"}],"check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2196349/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=kernel-dk.20230601.gappssmtp.com\n header.i=@kernel-dk.20230601.gappssmtp.com header.a=rsa-sha256\n header.s=20230601 header.b=pqqp9zH/;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; 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helo=mail-ot1-x333.google.com","X-Spam_score_int":"-18","X-Spam_score":"-1.9","X-Spam_bar":"-","X-Spam_report":"(-1.9 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1,\n DKIM_VALID=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001,\n SPF_PASS=-0.001 autolearn=ham autolearn_force=no","X-Spam_action":"no action","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"qemu development ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"},"content":"gsource_check() only looks at the ppoll revents for the io_uring fd,\nbut CQEs can be posted during gsource_prepare()'s io_uring_submit()\ncall via kernel task_work processing on syscall exit. These completions\nare already sitting in the CQ ring but the ring fd may not be signaled\nyet, causing gsource_check() to return false.\n\nAdd a fallback io_uring_cq_ready() check so completions that arrive\nduring submission are dispatched immediately rather than waiting for\nthe next ppoll() cycle.\n\nSigned-off-by: Jens Axboe \n---\n util/fdmon-io_uring.c | 14 +++++++++++++-\n 1 file changed, 13 insertions(+), 1 deletion(-)","diff":"diff --git a/util/fdmon-io_uring.c b/util/fdmon-io_uring.c\nindex 96392876b490..124e40594c17 100644\n--- a/util/fdmon-io_uring.c\n+++ b/util/fdmon-io_uring.c\n@@ -352,7 +352,19 @@ static void fdmon_io_uring_gsource_prepare(AioContext *ctx)\n static bool fdmon_io_uring_gsource_check(AioContext *ctx)\n {\n gpointer tag = ctx->io_uring_fd_tag;\n- return g_source_query_unix_fd(&ctx->source, tag) & G_IO_IN;\n+\n+ /* Check ppoll revents (normal path) */\n+ if (g_source_query_unix_fd(&ctx->source, tag) & G_IO_IN) {\n+ return true;\n+ }\n+\n+ /*\n+ * Also check for CQEs that may have been posted during prepare's\n+ * io_uring_submit() via task_work on syscall exit. Without this,\n+ * the main loop can miss completions and sleep in ppoll() until the\n+ * next timer fires.\n+ */\n+ return io_uring_cq_ready(&ctx->fdmon_io_uring);\n }\n \n /* Dispatch CQE handlers that are ready */\n","prefixes":["2/2"]}