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 X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F8F7C433E0 for ; Tue, 26 May 2020 19:46:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 49C26204EA for ; Tue, 26 May 2020 19:46:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590522405; bh=JF2mJpH+HydxO3JSBpjf7QgE5k6YKEl14ZaTJj0kxyA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=lSgD6k1QVje+fG9Kk97W8afwww/rgkvXUrmxfP4o7fcBiT9p64jsb7qrzhf83hwwH 6rmA2rWwKZkVBCv0j67OZJGp7+s00dW/r1bSOkTO43LzEer1YtRKGLKJy0gSMi2XbQ JR/T1c6H/UkGWH/Rk09OLZFKLWIusGA4eaVXjY88= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390026AbgEZTqo (ORCPT ); Tue, 26 May 2020 15:46:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39718 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389798AbgEZTqo (ORCPT ); Tue, 26 May 2020 15:46:44 -0400 Received: from mail-qk1-x742.google.com (mail-qk1-x742.google.com [IPv6:2607:f8b0:4864:20::742]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E6BF9C03E96D for ; Tue, 26 May 2020 12:46:43 -0700 (PDT) Received: by mail-qk1-x742.google.com with SMTP id s1so21927241qkf.9 for ; Tue, 26 May 2020 12:46:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=I0RoJLS4GC+98Xv+xGkQ27w/dIAY9pprJAGrxJoHF3k=; b=FnPdjB6e7/tqWtVykaVTskwAjpls12vQlfJQJxiH4S+BUEGGO48GecqBvHdjRa3aln EykDdNf+9rKjcktMZdPv0WwvpBgTqn4aTtEM5Hv5KHoh6UhWeU7xcVAKAWuBhiLAZwYu YyOGFNelG1/fgX8H9GhCOaTnPIX2fGZTRs/QmVZligGszitncesga8UPdW+warcyZ6Ls ocOIoXU/5xu1IKXDm70aYXKQgR67shgrq8rwy786LwrVURbMeWSTBHd6vPXV0lTIMkFc xHV2TZyvHKpZ2TQr4sEdLvYiLSuYZ09UNNjJFVSdkRqpDkivxD+G0LBd8rzdS0SAckBD vYfA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=I0RoJLS4GC+98Xv+xGkQ27w/dIAY9pprJAGrxJoHF3k=; b=uevGDC2asbjgDuutp5pC8hv7wPx1JFsrUda8WAirHk58mfoVWjJMd8NBfJ3SUjKd8l 7YhlNrzW/qMCa/D4HRKNH+d76D6SqHI5PA05quoZ2JoP79S+gN5NKD4wR2ULI5sj8EAj TqAkJrsI8SUP9V5JOqJlR8WDsqvklW/6msRQJY3defURCAkv75idoFkhg0SzFIEggz2k zM9nXBhBBdiBIxGyD0zHw0uuIzOiY4xC9Aad/hnnDXYEQ2CSGxmTb28r2JbQAIUNmBMc 3ZN7OREdOgNYDp3b5MYgYOu/+XAOZcA/QtjR4byH//bP0mc513v5sb18o1GaRq6gs7J/ wjLQ== X-Gm-Message-State: AOAM530Ykh/qPGXvfNaDmeYAnh5ZmkUO+iP/0TW1wTKsqX2c5vJ6Pg/b uKUZL/knGS0/BBL3RpJ5Pl8= X-Google-Smtp-Source: ABdhPJzQ/6G6ZodV0qRRzRMUX3CKTGqLX59UsImmzMS+2+fFOeDLOxj1XiV9r3CLhRgj3ObIi8l65Q== X-Received: by 2002:a05:620a:205c:: with SMTP id d28mr518435qka.436.1590522402921; Tue, 26 May 2020 12:46:42 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:85c0]) by smtp.gmail.com with ESMTPSA id n63sm484886qkn.104.2020.05.26.12.46.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 May 2020 12:46:42 -0700 (PDT) Date: Tue, 26 May 2020 15:46:41 -0400 From: Tejun Heo To: Sebastian Andrzej Siewior Cc: linux-kernel@vger.kernel.org, Lai Jiangshan , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Linus Torvalds Subject: Re: [PATCH 0/3] workqueue: Make the workqueue code PREEMPT_RT safe Message-ID: <20200526194641.GF83516@mtj.thefacebook.com> References: <20200513162732.977489-1-bigeasy@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200513162732.977489-1-bigeasy@linutronix.de> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Wed, May 13, 2020 at 06:27:29PM +0200, Sebastian Andrzej Siewior wrote: > The series changes `wq_manager_wait' from waitqueues to simple > waitqueues and its internal locking (pool::lock and wq_mayday_lock) to > raw spinlocks so that workqueues can be used on PREEMPT_RT from truly > atomic context. No objection from workqueue side but the comment in swait.h doesn't look too encouraging. Kinda difficult to make a call from my side. Linus, does this qualify as the RT use case you had on mind? Thanks. -- tejun