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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4EEAC001DF for ; Wed, 2 Aug 2023 18:11:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233744AbjHBSK7 (ORCPT ); Wed, 2 Aug 2023 14:10:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58068 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234351AbjHBSKr (ORCPT ); Wed, 2 Aug 2023 14:10:47 -0400 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F28F52704 for ; Wed, 2 Aug 2023 11:10:35 -0700 (PDT) Received: by mail-pl1-x62e.google.com with SMTP id d9443c01a7336-1bba48b0bd2so1072795ad.3 for ; Wed, 02 Aug 2023 11:10:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1690999835; x=1691604635; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=ldvDwR+TbK2QfS8E1DpAj886KyiAxDSW8+aMumyhSP4=; b=YCD0Qgu9KEs/01vlshq7vgamQUq2iwEcGVAA/dU6ceJRnKZ0R4kTQKnLUs7qoJ1KTw y2WzL0DJw8CLtzDO9d3XYhzUKw6ewLW3gYXDe+AMmM4R0abPYilMxLve0Wg4/fb5vOV7 xBYHpxLOrrkladpdurehm8/OlkHS+AbhY65oF6XnBQY2UZzRksq4rJBKKfLRXACS1Vdc XI45SUPCgN35/sOA7ohp9IMl+fMf9EOOEk8MOpl1INLVsn6j0tjLbunLACuQxyPjS+S8 Cu8IuSSNgiTWRvTW71MnHrdJuEozIOks6JD9Pv8oprCbwnN9UWO7wfH9mH3103W0k3va lFFQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690999835; x=1691604635; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=ldvDwR+TbK2QfS8E1DpAj886KyiAxDSW8+aMumyhSP4=; b=kdo8/+6sicfuA87NkDvGGQEy3Yg7MOXBtwm5tALpIZtQQMbxvlEWzEQzEIMwywmUCF S3J07vt8nunHTcIm3KXrtLvRD6t50bLe/pAwNEXnbJznB7OpiiGQNsDNYzgYDKdZAfhw U54zcFihgVYZjnk1NRn4nmooo3+VOD/m0OH4vY15gzzQkMrqVF1qek/+uw7Ldg0jMrR/ kREQOAy7Ju91CNzL2sNzqiUv5lL8t2K/5wzKZ8O1E+shMJwtElWXenk8aesXjSFDbol7 0QiRQkNbcgxmbrNMuwJIIElZoTFKVPtJuxdCDzH5p0mVWqim+/KlNDDEKDHUVy1l9Yyr 7HmQ== X-Gm-Message-State: ABy/qLYMjcYA+uSoAB+By9U3IQsqU1bDmv7+UADatXNNDWHYMZU1u8JZ vOI4vGU6fFgLVdbHGDfliZQ= X-Google-Smtp-Source: APBJJlEDNO9oKf3ODmJZdN4zDJ7iVeH5HMme3KrhK5nNF1JkAnS+pS9euqDGAEk4v361jdcFVYPA6w== X-Received: by 2002:a17:902:e5c4:b0:1bb:5b88:73da with SMTP id u4-20020a170902e5c400b001bb5b8873damr17310361plf.61.1690999835179; Wed, 02 Aug 2023 11:10:35 -0700 (PDT) Received: from localhost (dhcp-72-235-13-41.hawaiiantel.net. [72.235.13.41]) by smtp.gmail.com with ESMTPSA id iz12-20020a170902ef8c00b001b9de2b905asm12761279plb.231.2023.08.02.11.10.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Aug 2023 11:10:34 -0700 (PDT) Sender: Tejun Heo Date: Wed, 2 Aug 2023 08:10:33 -1000 From: Tejun Heo To: Aaron Tomlin Cc: peterz@infradead.org, jiangshanlai@gmail.com, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 0/2] workqueue: Introduce PF_WQ_RESCUE_WORKER Message-ID: References: <20230801105301.952042-1-atomlin@atomlin.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230801105301.952042-1-atomlin@atomlin.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Tue, Aug 01, 2023 at 11:53:01AM +0100, Aaron Tomlin wrote: > > You really shouldn't be setting affinities on kworkers manually. There's > > no way of knowing which kworker is going to execute which workqueue. > > Please use the attributes API and sysfs interface to modify per-workqueue > > worker attributes. If that's not sufficient and you need finer grained > > control, the right thing to do is using kthread_worker which gives you a > > dedicated kthread that you can manipulate as appropriate. > > I completely agree. Each kworker has PF_NO_SETAFFINITY applied anyway. > If I understand correctly, only an unbound kworker can have their CPU > affinity modified via sysfs. The objective of this series was to easily > identify a rescuer kworker from user-mode. But why do you need to identify rescue workers? What are you trying to achieve? Thanks. -- tejun