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[2620:137:e000::1:20]) by mx.google.com with ESMTP id ky20-20020a170907779400b00730cd86905dsi557123ejc.80.2022.08.04.03.48.47; Thu, 04 Aug 2022 03:49:12 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20210112 header.b=efxhZZtV; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230380AbiHDKT0 (ORCPT + 99 others); Thu, 4 Aug 2022 06:19:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52992 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229687AbiHDKTX (ORCPT ); Thu, 4 Aug 2022 06:19:23 -0400 Received: from mail-wm1-x32a.google.com (mail-wm1-x32a.google.com [IPv6:2a00:1450:4864:20::32a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AFB942BCA for ; Thu, 4 Aug 2022 03:19:21 -0700 (PDT) Received: by mail-wm1-x32a.google.com with SMTP id n185so10050067wmn.4 for ; Thu, 04 Aug 2022 03:19:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc; bh=czc1T/pKPyg7RnSQHhci8IuoQWmOJ7tlHwHzQ6eQTjM=; b=efxhZZtVUq8SzQ86QyLAe3Ii3McULNSOS5c9BT5DwcnHKqOiy0dK1WigXCDZur6W6O 1T894PPr1v9wfY7e/JZeNYeiMTZizMj5YM0xVb/o2PBePekrWYUfaiiBuFqkME4+7xwZ YoF5i13gxy/24HOc3TXn+FvtSIveiRIPTMGv6X35hydqSepm5Oitvtj2r4QVoMPYZvCO YdU65OvtK1aV7lfn1sVHQ14H6GB4jVljU28MddzmvMjyuOiyMuin57o2G/U00ekFeCYu 5qkdgUCurBKE/EhS5nCCoWWJOGAqt+ywF/VdxCU4U60T2UeABgijsTQfWv4YYf6jUvGT yifg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc; bh=czc1T/pKPyg7RnSQHhci8IuoQWmOJ7tlHwHzQ6eQTjM=; b=la5Snsqb47pVFnFWltbPlVSEQAz7n0VkvVlYeRRm6p0SHu4ySfWjpmBAIvisksWWPj r97OZMEU24u/zSiZSM6JHsPRhxpMeVA2qnAyE2DPz4g2jS8B2iiDfSAbkmBZU2JU3hsU ji7OS8IBPiOinJ1eU8Aqb6afXFGeycZF/eExFHCbVChBntYZ5C8r01ZImekm+fxf9y5C YkOrOi3lw60aOcgo0Lk6pSwp2XZz8MRrMO/+nppsnmMRflkqQ6CeQFNUVdqk6DDqZBGX zabmfqnOZCoCM7eguC/ybcVO/5KbmWf2+kuyY0m/T4tIbY+W32GLtaGDtK9HGhFQJx+R PdbQ== X-Gm-Message-State: ACgBeo2td4jEoLeGmG19ExQUTZFpAwnQubDcphPU//MZ6oU7Px5ahfr7 MYm1dAdAZJIG+VzhlkS1CCxmWl+bNNDC0fntCqY= X-Received: by 2002:a05:600c:1ca9:b0:3a5:125:3738 with SMTP id k41-20020a05600c1ca900b003a501253738mr4484309wms.161.1659608360199; Thu, 04 Aug 2022 03:19:20 -0700 (PDT) MIME-Version: 1.0 References: <20220622140853.31383-1-pmladek@suse.com> In-Reply-To: From: Lai Jiangshan Date: Thu, 4 Aug 2022 18:19:08 +0800 Message-ID: Subject: Re: [PATCH] workqueue: Make create_worker() safe against spurious wakeups To: Petr Mladek Cc: Tejun Heo , Michal Hocko , LKML Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 4, 2022 at 4:57 PM Lai Jiangshan wrote: ; > > There might be some wakeups from wake_up_worker() since it is in > the idle list. These wakeups will be "spurious wakeups" in the view > of the completion subsystem. > Oh, sorry, I was wrong. "complete(&worker->ready_to_start);" and "worker_enter_idle(worker);" are in the same pool lock region. There are no "spurious wakeups" from "wake_up_worker()" as I have wrongly described.