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 52EC8C32793 for ; Wed, 18 Jan 2023 18:26:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229660AbjARS0B (ORCPT ); Wed, 18 Jan 2023 13:26:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229589AbjARS0A (ORCPT ); Wed, 18 Jan 2023 13:26:00 -0500 Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com [IPv6:2607:f8b0:4864:20::102a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 155E654217; Wed, 18 Jan 2023 10:26:00 -0800 (PST) Received: by mail-pj1-x102a.google.com with SMTP id u1-20020a17090a450100b0022936a63a21so3270581pjg.4; Wed, 18 Jan 2023 10:26:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; 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=gfdBFnYu5sNZX5xFe5dSgbNFlKRXmyEjirqJcinL8sM=; b=KLz8M1LacL19djpn1QnVHpwDLfqm5ZPqvEkxH+PEoCS88M/dddzhvXp+B5xsuS3dRq Dozgqm8vdidtYNCMjy93Bjj+GA64O/FZh7XHnfyW/F+71TYelRGQNaVj6/VQ79r9XpnJ 9eEchAroDQfDazRdPqrrfUVkePd61pk4FxXxPt6FudJnG1gYkllewxhez8Q/xr5dniZH 03DD12mqiseHav5y7aI9Nr3lPsL82m26Rfura9SbI4eEtY0NrmPkKwZKUXEuVz/sIPMZ x2Hil+L2EjPt1eOgaqUes2EAHjEXktuePQ0epQsYCuhplCJy+mM+v/GG9oVvQQh4Fqcc nGsg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; 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=gfdBFnYu5sNZX5xFe5dSgbNFlKRXmyEjirqJcinL8sM=; b=dWmssoRoB0zOk9bK7QzC9+wnWeMHu1qSz+wUu6OElLMWeFIyy7pXnJEsW8BC4UmgzG vaZteQ4KMoOXy4R9rXven61hteWQSnzY3GE/u01myJRPHiAsIRcBoHZvm2tMMOGt7UkT zkzJbfkeYkOT7hiBoS9GD8loULLUK6EzEZPdYzHxjP5g/kUn8CSJBvJ0d0b8mXYswwxq BsaWCjvCKWl6qAHAj9s6JmwALTkGoisrtHLAwp34su1DndISfA1DhEJ4ng2ug0R15KsM Tx2HhIms58p0oDrBJz5wknyNA4woZZ8x+EdGU3g3PLa6b/Qp4423FtK/sdJcMJ+uNmq2 bI3A== X-Gm-Message-State: AFqh2kpeh05l8tMGKfNX1HOjodt7Vd82gwHLGVJ2m7tFkRI17jZiDLpr h1oZR7R81wxMrPVkBHBlJFbDn/CbX98= X-Google-Smtp-Source: AMrXdXuddP+QLqbpiJjVVoBjiKzMya8ya11h0O34Qm4U4bXH8ycZ+67WnlQwbpCawBq+FhbU3MQ+bw== X-Received: by 2002:a17:90a:430f:b0:229:46f0:6f71 with SMTP id q15-20020a17090a430f00b0022946f06f71mr7957578pjg.45.1674066359379; Wed, 18 Jan 2023 10:25:59 -0800 (PST) Received: from localhost (2603-800c-1a02-1bae-a7fa-157f-969a-4cde.res6.spectrum.com. [2603:800c:1a02:1bae:a7fa:157f:969a:4cde]) by smtp.gmail.com with ESMTPSA id g4-20020a17090a640400b0022910fa4d1csm1626154pjj.46.2023.01.18.10.25.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Jan 2023 10:25:59 -0800 (PST) Sender: Tejun Heo Date: Wed, 18 Jan 2023 08:25:57 -1000 From: Tejun Heo To: Sandeep Dhavale Cc: Nathan Huckleberry , Daeho Jeong , Eric Biggers , Sami Tolvanen , Lai Jiangshan , Jonathan Corbet , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] workqueue: Add WQ_SCHED_FIFO Message-ID: References: <20230113210703.62107-1-nhuck@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Wed, Jan 18, 2023 at 10:22:32AM -0800, Sandeep Dhavale wrote: > If with the kernel config option, every WQ_HIGHPRI is elevated to > sched_fifo_low, wouldn't that be kind of defeating the purpose? Having > another class for even more urgent work is better in my opinion. I mean, everybody thinks their work items are the most important. Even with explicit FIFO, you're still gonna have similar problems as people crowd that flag. If this is a concern, please benchmark with realistic scenarios and consider other options (e.g. maybe that problematic workqueue doesn't need to be HIGHPRI or should be split somehow). Right now, I don't think there are enough justifications for adding another level. Thanks. -- tejun