From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on gnuweeb.org X-Spam-Level: * X-Spam-Status: No, score=1.9 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_SOFTFAIL autolearn=no autolearn_force=no version=3.4.6 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02D88C433F5 for ; Thu, 21 Apr 2022 13:45:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1386729AbiDUNsG (ORCPT ); Thu, 21 Apr 2022 09:48:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58746 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1386691AbiDUNsD (ORCPT ); Thu, 21 Apr 2022 09:48:03 -0400 Received: from mail-wm1-x32c.google.com (mail-wm1-x32c.google.com [IPv6:2a00:1450:4864:20::32c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C95FAE6C for ; Thu, 21 Apr 2022 06:45:13 -0700 (PDT) Received: by mail-wm1-x32c.google.com with SMTP id bg25so2527020wmb.4 for ; Thu, 21 Apr 2022 06:45:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=iwf7B/JoObKukmaAm7gltrLYGrS6GCfPNu+o9swiNC0=; b=MofLb1xS4gd/3a/vyjdEDkC3T5v8FNu3+c0rPDkSTDqcB/IHhVcociPazVYbynn8gi 4O4H4wKyvC5woL6WzNe0Pma5Qr/BiDGGjjkuKUEwdrB4/DEpbJAO7av1KxJkrS51exqe tKYoUZvHU3hI0f9A3L8NyogV/1Kmah5Rjoi/Zrm0HQgA2nUm3yW/iv6SjQ9HRPZefwm9 uo5fPOHD6SQ5+/Mpx5S2TaXJ3LdH8LP5xfgCWGzI9v8edqPIm03EPzREROmtKpiTxoYp MVM2Vs8NF7sqNMA3hYS9KUv/BFq/KSl8saadun+nZMehAYCtf2V2IbYEyYlNKcrwbfN2 0ACw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=iwf7B/JoObKukmaAm7gltrLYGrS6GCfPNu+o9swiNC0=; b=ky4mdLCN585aVbnMrT/WbQ5YYt5qaGcb4NCHZkadb9TRbKzmpaBIsuwyLp5cutZFz6 BG0Vikl5J7Sn+3DNkEEeZ4c2rThz8uUY2RRjIoPa3yHvB+eqpPsTEP5xTjMr3Kgx1baY hLUyPT9z7z276araBfP9hqH2rYfX1a2CtZCBGyPLg87khdBt5hPoZpF281Imw2+7yiXX x9yzKTaVmuK5eUlBa2zyVoLF+CqG6Ewy/RFQrLQPjUsUXpqVi78X261JXOSbR1wRE4ja 4XF43uKWYGDr+rAc0jMyRY2osmPQDcRbnMv9mloiWSF8YlTCXmaKNNcocIBthxJZCB8a TqUQ== X-Gm-Message-State: AOAM532zoOodOjUzuvtdE1e5t+vVlPXpKOEkVm7r8DjmVpK0w1DgqDLt WZG96VN/gBj1TQG9AE3xOl2GAjQbPkQ= X-Google-Smtp-Source: ABdhPJxR/22gW7liJGIe4s2okqxNdsah+az48ygUQxb8tbOgDfhOR+eF2G3cSNj34FUwL3j//MMbyg== X-Received: by 2002:a05:600c:4e87:b0:38e:ada5:5c6f with SMTP id f7-20020a05600c4e8700b0038eada55c6fmr8546158wmq.21.1650548711961; Thu, 21 Apr 2022 06:45:11 -0700 (PDT) Received: from 127.0.0.1localhost ([148.252.129.218]) by smtp.gmail.com with ESMTPSA id m7-20020adfe0c7000000b002060e7bbe49sm2837821wri.45.2022.04.21.06.45.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 21 Apr 2022 06:45:11 -0700 (PDT) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com Subject: [RFC 04/11] io_uring: don't take ctx refs in tctx_task_work() Date: Thu, 21 Apr 2022 14:44:17 +0100 Message-Id: <92eb2d1f934ad16752cc3b764d8be75ca04d1ffe.1650548192.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.36.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Now we ban any new req-task_works to be added after we start the task cancellation. Because tctx is removed from ctx lists only during task cancellation, and considering that it's removed from the task context, we'll have current accounted in all rings tctx_task_work() is working with and so they will stay alive at least awhile it's running. Don't takes extra ctx refs. Signed-off-by: Pavel Begunkov --- fs/io_uring.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index ec5fe55ab265..8d5aff1ecb4c 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2475,7 +2475,6 @@ static void ctx_flush_and_put(struct io_ring_ctx *ctx, bool *locked) mutex_unlock(&ctx->uring_lock); *locked = false; } - percpu_ref_put(&ctx->refs); } static inline void ctx_commit_and_unlock(struct io_ring_ctx *ctx) @@ -2506,7 +2505,6 @@ static void handle_prev_tw_list(struct io_wq_work_node *node, *ctx = req->ctx; /* if not contended, grab and improve batching */ *uring_locked = mutex_trylock(&(*ctx)->uring_lock); - percpu_ref_get(&(*ctx)->refs); if (unlikely(!*uring_locked)) spin_lock(&(*ctx)->completion_lock); } @@ -2537,7 +2535,6 @@ static void handle_tw_list(struct io_wq_work_node *node, *ctx = req->ctx; /* if not contended, grab and improve batching */ *locked = mutex_trylock(&(*ctx)->uring_lock); - percpu_ref_get(&(*ctx)->refs); } req->io_task_work.func(req, locked); node = next; -- 2.36.0