From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37EE3C433E6 for ; Mon, 1 Mar 2021 13:08:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0159764E40 for ; Mon, 1 Mar 2021 13:08:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235363AbhCANIS (ORCPT ); Mon, 1 Mar 2021 08:08:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235413AbhCANHN (ORCPT ); Mon, 1 Mar 2021 08:07:13 -0500 Received: from mail-wm1-x334.google.com (mail-wm1-x334.google.com [IPv6:2a00:1450:4864:20::334]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 81FA0C061356 for ; Mon, 1 Mar 2021 05:06:16 -0800 (PST) Received: by mail-wm1-x334.google.com with SMTP id o7-20020a05600c4fc7b029010a0247d5f0so2973495wmq.1 for ; Mon, 01 Mar 2021 05:06:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=xxqcHyisP1GImoGM8hEjU50hzjhJ26ZTKKwXvtui6Ko=; b=hcex4GqtZMkzfXtT27GMZzYrdE7ljECJsWv2QSCYCPRIo1tpGzC5QUwZ4GkZSGg4sq jTFPtgQwZFqBrrg4r5JV6fLvKcIcNEqmKJ6l1iNfytD51y/Mp6kbqklwKD60WBUPWxrb lvDJt/gzZ1TO4FJHIAT+jpLe8Kq++Sx2Y5v26qVdnRwtjBF8wGbtDOg8JV6F0a7YL+4r BejcgOmAjwgDmzmn2GOWlJ08ig1kfdgbIR+nzfJbVW+1UYrkRZfpPZTQVSLbRH0lraHh CiwWjX/F+Rb/yxFY09FRrYIpup0KXyUaLY5ujEpwg/642EeGdszJTqObuSIjFtKJwhAe b59w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=xxqcHyisP1GImoGM8hEjU50hzjhJ26ZTKKwXvtui6Ko=; b=BzsV+7rnLT5trdvLcNh9MUSAtBqma4NfRMYLWnybEcALvMsnQtNKm+qtjv3DajNZj/ +tinI1wcQspHljv65F93n6ZvRLl7TzR8hY3zVch1Xfbb1RPCd1QrfdyVClQOrIkYGx5K nowpcOhOm8FY9twEXMet43ucgyhMbmD6NsbBVPSfwyVzZ46ECSxbKcfOetTDUAkktFX0 62/bREX2IEVDt4RtyTZHX0GP8I9hUXo/jRPWTh++Od/lC39l7ojH+UOGqTl2rpd6Obxn YLM3FL512JBoHexpQfK+x1WtBvD1GuJ+G38uAOtTA7t7FlbA67X4eBzTmDMQuvdCst6V hZhw== X-Gm-Message-State: AOAM530W+1sM2whRFyKYbE6EVsxRiGPe2sPFUCLzk9WCUcO7bBOu5opQ 4QiowT3DMv507aV0fMyuSxk= X-Google-Smtp-Source: ABdhPJwFWtl28jjeZkffuj8NpKlUFWReWYYmdqNsb9ll/jO2rRbU1VEHYBknDEkrqURNeBNcj6ySVQ== X-Received: by 2002:a7b:cb81:: with SMTP id m1mr15867488wmi.117.1614603975279; Mon, 01 Mar 2021 05:06:15 -0800 (PST) Received: from localhost.localdomain ([85.255.232.38]) by smtp.gmail.com with ESMTPSA id j16sm1898903wmi.2.2021.03.01.05.06.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 01 Mar 2021 05:06:14 -0800 (PST) From: Pavel Begunkov To: Jens Axboe , io-uring@vger.kernel.org Subject: [PATCH 1/2] io_uring: kill sqo_dead and sqo submission halting Date: Mon, 1 Mar 2021 13:02:15 +0000 Message-Id: <7c5c98128324970ea148f47653333b96d0a04117.1614603610.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org As SQPOLL task doesn't poke into ->sqo_task anymore, there is no need to kill the sqo when the master task exits. Before it was necessary to avoid races accessing sqo_task->files with removing them. Signed-off-by: Pavel Begunkov --- fs/io_uring.c | 40 +++------------------------------------- 1 file changed, 3 insertions(+), 37 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 54e6c4db9620..6529761b77eb 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -338,7 +338,6 @@ struct io_ring_ctx { unsigned int drain_next: 1; unsigned int eventfd_async: 1; unsigned int restricted: 1; - unsigned int sqo_dead: 1; unsigned int sqo_exec: 1; /* @@ -1972,7 +1971,7 @@ static void __io_req_task_submit(struct io_kiocb *req) /* ctx stays valid until unlock, even if we drop all ours ctx->refs */ mutex_lock(&ctx->uring_lock); - if (!ctx->sqo_dead && !(current->flags & PF_EXITING) && !current->in_execve) + if (!(current->flags & PF_EXITING) && !current->in_execve) __io_queue_sqe(req); else __io_req_task_cancel(req, -EFAULT); @@ -6583,8 +6582,7 @@ static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries) if (!list_empty(&ctx->iopoll_list)) io_do_iopoll(ctx, &nr_events, 0); - if (to_submit && !ctx->sqo_dead && - likely(!percpu_ref_is_dying(&ctx->refs))) + if (to_submit && likely(!percpu_ref_is_dying(&ctx->refs))) ret = io_submit_sqes(ctx, to_submit); mutex_unlock(&ctx->uring_lock); } @@ -7823,7 +7821,7 @@ static int io_sq_thread_fork(struct io_sq_data *sqd, struct io_ring_ctx *ctx) clear_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state); reinit_completion(&sqd->completion); - ctx->sqo_dead = ctx->sqo_exec = 0; + ctx->sqo_exec = 0; sqd->task_pid = current->pid; current->flags |= PF_IO_WORKER; ret = io_wq_fork_thread(io_sq_thread, sqd); @@ -8534,10 +8532,6 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) { mutex_lock(&ctx->uring_lock); percpu_ref_kill(&ctx->refs); - - if (WARN_ON_ONCE((ctx->flags & IORING_SETUP_SQPOLL) && !ctx->sqo_dead)) - ctx->sqo_dead = 1; - /* if force is set, the ring is going away. always drop after that */ ctx->cq_overflow_flushed = 1; if (ctx->rings) @@ -8697,19 +8691,6 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx, } } -static void io_disable_sqo_submit(struct io_ring_ctx *ctx) -{ - mutex_lock(&ctx->uring_lock); - ctx->sqo_dead = 1; - if (ctx->flags & IORING_SETUP_R_DISABLED) - io_sq_offload_start(ctx); - mutex_unlock(&ctx->uring_lock); - - /* make sure callers enter the ring to get error */ - if (ctx->rings) - io_ring_set_wakeup_flag(ctx); -} - /* * We need to iteratively cancel requests, in case a request has dependent * hard links. These persist even for failure of cancelations, hence keep @@ -8722,7 +8703,6 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx, bool did_park = false; if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) { - io_disable_sqo_submit(ctx); did_park = io_sq_thread_park(ctx->sq_data); if (did_park) { task = ctx->sq_data->thread; @@ -8843,7 +8823,6 @@ static void io_uring_cancel_sqpoll(struct io_ring_ctx *ctx) if (!sqd) return; - io_disable_sqo_submit(ctx); if (!io_sq_thread_park(sqd)) return; tctx = ctx->sq_data->thread->io_uring; @@ -8888,7 +8867,6 @@ void __io_uring_task_cancel(void) /* make sure overflow events are dropped */ atomic_inc(&tctx->in_idle); - /* trigger io_disable_sqo_submit() */ if (tctx->sqpoll) { struct file *file; unsigned long index; @@ -9019,22 +8997,14 @@ static int io_sqpoll_wait_sq(struct io_ring_ctx *ctx) do { if (!io_sqring_full(ctx)) break; - prepare_to_wait(&ctx->sqo_sq_wait, &wait, TASK_INTERRUPTIBLE); - if (unlikely(ctx->sqo_dead)) { - ret = -EOWNERDEAD; - goto out; - } - if (!io_sqring_full(ctx)) break; - schedule(); } while (!signal_pending(current)); finish_wait(&ctx->sqo_sq_wait, &wait); -out: return ret; } @@ -9120,8 +9090,6 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, goto out; } ret = -EOWNERDEAD; - if (unlikely(ctx->sqo_dead)) - goto out; if (flags & IORING_ENTER_SQ_WAKEUP) wake_up(&ctx->sq_data->wait); if (flags & IORING_ENTER_SQ_WAIT) { @@ -9493,7 +9461,6 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p, */ ret = io_uring_install_fd(ctx, file); if (ret < 0) { - io_disable_sqo_submit(ctx); /* fput will clean it up */ fput(file); return ret; @@ -9502,7 +9469,6 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p, trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags); return ret; err: - io_disable_sqo_submit(ctx); io_ring_ctx_wait_and_kill(ctx); return ret; } -- 2.24.0