From patchwork Wed Aug 9 19:43:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 13348402 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EAB0EC001E0 for ; Wed, 9 Aug 2023 19:43:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230283AbjHITnQ (ORCPT ); Wed, 9 Aug 2023 15:43:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60090 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231251AbjHITnN (ORCPT ); Wed, 9 Aug 2023 15:43:13 -0400 Received: from mail-pf1-x430.google.com (mail-pf1-x430.google.com [IPv6:2607:f8b0:4864:20::430]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C232A10F3 for ; Wed, 9 Aug 2023 12:43:12 -0700 (PDT) Received: by mail-pf1-x430.google.com with SMTP id d2e1a72fcca58-6873f64a290so23863b3a.0 for ; Wed, 09 Aug 2023 12:43:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20221208.gappssmtp.com; s=20221208; t=1691610192; x=1692214992; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=IVHXPxLmxfd5CWTOTrBfmptnMeO3orQcJQg34vrpu6k=; b=BuW8gzX2IVPME+eQoZrjHuxemw2dByucIImWWi4Y3OLhj8sePv4NAZUuFPXz9eCaWE +rz8y04w77xwCj9vF9yCh7D5i7OlRg/xyBxSPUU4y13mnwVH0ST1Sfj8leMQZmXPaH3y QboEvRQW+11++rtmgqMgF3Xaz6wjJZkafdAXp/V+yY8Mpxay2Ta2HwFDsJHw2wrKQLqA b0RMU1tfkS448sXWfzxN72hDeH1MQ+sen0IuHNi3KW3cQP5NzthR/MfpwLFlPK8XZUG+ +ZFXSFsG+ext42TH59q5PYQGbFCHCMrE9sJ2GaMYC2w7jfR6nQmerI8FnVN4JJH+lGKC x+WQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691610192; x=1692214992; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=IVHXPxLmxfd5CWTOTrBfmptnMeO3orQcJQg34vrpu6k=; b=aXG+v1ioNEBL4RuQrXNmqz91eIDvAZohAne+2RNBGEqn6NR8trHdtP30bCIRTLhmKU CkCRYDil/zxhm99eGv3DXKAgvT7NblEypse75u2s8fKkCLHlL/DSo9r4HIg36i/XBQFb qb24LCtk0Z42uOEP7S1k/Ismgn7jW5tMXTNjPDsm5Hq5L/6tIHNRgndmAjWcOANPRDcn VW1Lwh8CAs7gEiHAoYikVzT+OcVwh+ccsNfACgmbB0RGBjGN4XReaSrygNm7y8futZ95 n0xqyUOf8dRKJn6Syj4dOFUYkH4VGcPlWddJOshukXF1Ovh9wY2abDnfRFYOmRnBpUAu +h1Q== X-Gm-Message-State: AOJu0YwxwCqrMnsMZiAdB/9zEDgjgbuK+IcD/9u7UHJMmsJxvhsQWv6W GE7gv8LyDpFbHQyPQaAW1dlY3Q4D1v7/ojuTmiE= X-Google-Smtp-Source: AGHT+IH5S02ZwEgRA6kg7g+bXpoVaHnAlRHNbHivQ0GffdbvDPd7jnKL3Bsp0ocH/Z+YFCAvdjoRTw== X-Received: by 2002:a17:902:c952:b0:1b8:aded:524c with SMTP id i18-20020a170902c95200b001b8aded524cmr126993pla.1.1691610191800; Wed, 09 Aug 2023 12:43:11 -0700 (PDT) Received: from localhost.localdomain ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id l19-20020a170902eb1300b001b8953365aesm11588919plb.22.2023.08.09.12.43.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Aug 2023 12:43:11 -0700 (PDT) From: Jens Axboe To: io-uring@vger.kernel.org Cc: Jens Axboe Subject: [PATCH 1/3] io_uring/io-wq: don't grab wq->lock for worker activation Date: Wed, 9 Aug 2023 13:43:04 -0600 Message-Id: <20230809194306.170979-2-axboe@kernel.dk> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230809194306.170979-1-axboe@kernel.dk> References: <20230809194306.170979-1-axboe@kernel.dk> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org The worker free list is RCU protected, and checks for workers going away when iterating it. There's no need to hold the wq->lock around the lookup. Signed-off-by: Jens Axboe --- io_uring/io-wq.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c index 399e9a15c38d..3e7025b9e0dd 100644 --- a/io_uring/io-wq.c +++ b/io_uring/io-wq.c @@ -909,13 +909,10 @@ void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work) clear_bit(IO_ACCT_STALLED_BIT, &acct->flags); raw_spin_unlock(&acct->lock); - raw_spin_lock(&wq->lock); rcu_read_lock(); do_create = !io_wq_activate_free_worker(wq, acct); rcu_read_unlock(); - raw_spin_unlock(&wq->lock); - if (do_create && ((work_flags & IO_WQ_WORK_CONCURRENT) || !atomic_read(&acct->nr_running))) { bool did_create;