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 46E16C001DE for ; Mon, 31 Jul 2023 23:35:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230445AbjGaXfz (ORCPT ); Mon, 31 Jul 2023 19:35:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231580AbjGaXfu (ORCPT ); Mon, 31 Jul 2023 19:35:50 -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 E1294E7C for ; Mon, 31 Jul 2023 16:35:47 -0700 (PDT) Received: by mail-pl1-x62e.google.com with SMTP id d9443c01a7336-1bbbbb77b38so29704615ad.3 for ; Mon, 31 Jul 2023 16:35:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1690846547; x=1691451347; 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=D44fwITHqOzKSCX1s1m0Tgwi/dhRYO0oEqL/14QyVoc=; b=RwgIt1duiUrRhjEcURhmbIveMW2obdPCNKGXb6SyeOvHZR0826BdFgBW+m39HFLPso DUH8zr7KlwmOome+VI658BCVSPsYShfq76RTIv/qDbzdvVlK6bbDyWg2ac11a4Lb5GSx mRm852k8BHW+7xljYLcen7D//++6wkauB/7aIELd9IJpFuurGVkBys27y8t9XO7vJ7c0 eFDIf3rxQekq7ycwxaAn7CaPxlHyXyvGhxyy8huCl5UjG1KeCDdrBSdsahbKecU0YC3b MRpnY3ZRRfPK/OynMXEOC+06dUQUb4Tvi/2n8rZa1LBaTQz7GpDMtmWUcH8fVJ1voAMq QEfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690846547; x=1691451347; 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=D44fwITHqOzKSCX1s1m0Tgwi/dhRYO0oEqL/14QyVoc=; b=cBjhxubWfkqeMCg4Mdp2HVdFAFiPVjnwnwL/qTlt3yf8VPgavN+5YuLOqhMeK//sdL qjzmBtKky/cTWM7m+orl8DWyj68gE1PTFdA6kQpINvMWUzS0lNk2eqH/NdiOgfL68ATc +WQF/pKOeT9yO6fmrpAU2nnbBLCbNmpfd0RJfnYi1jD1r6IRlT5tImOp+9Cb3vo+Pysr V3EkQjUR/cscHm3o8x+DKK2Y9lqBBX03gquF+Pc1u81bs56gTHBKFZ2wUrIHesYyZJbj 19GELI6YC9v56aUDTPiAPLPccmuQVJHKILB67O0g5/OILPYUj3MUjEMPOW/OgYQn5ga1 hDCQ== X-Gm-Message-State: ABy/qLYLPzm5Ymp8EZSjusVPIf1jLYMDj1rwdFuefCfcVOvDZrx1P4OB lJ+GVYpa8jx3zkXM22NjY1Q= X-Google-Smtp-Source: APBJJlGkgRGdtXar33TqGJe8AU5ERPlszqjEvb5w1jHguWNFfg5SU4jBQWLitU/ykPh/9ruK+HIEJQ== X-Received: by 2002:a17:903:1107:b0:1b8:5a32:2345 with SMTP id n7-20020a170903110700b001b85a322345mr10857206plh.22.1690846547133; Mon, 31 Jul 2023 16:35:47 -0700 (PDT) Received: from localhost ([2620:10d:c090:400::5:4a3a]) by smtp.gmail.com with ESMTPSA id b10-20020a170902d50a00b001b890b3bbb1sm9071400plg.211.2023.07.31.16.35.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 31 Jul 2023 16:35:46 -0700 (PDT) Sender: Tejun Heo Date: Mon, 31 Jul 2023 13:35:45 -1000 From: Tejun Heo To: Aaron Tomlin Cc: linux-kernel@vger.kernel.org, jiangshanlai@gmail.com, peterz@infradead.org Subject: Re: [RFC PATCH 0/2] workqueue: Introduce PF_WQ_RESCUE_WORKER Message-ID: References: <20230729135334.566138-1-atomlin@atomlin.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230729135334.566138-1-atomlin@atomlin.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Sat, Jul 29, 2023 at 02:53:32PM +0100, Aaron Tomlin wrote: > It can be useful to identify a rescue kworker since their CPU affinity > cannot be modified and their initial CPU assignment can be safely ignored. 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. Thanks. -- tejun