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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,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 D6E6AC4363D for ; Fri, 2 Oct 2020 08:32:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 538DB20719 for ; Fri, 2 Oct 2020 08:32:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="KCmB2Loi"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="JGKS+1g+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387654AbgJBIcf (ORCPT ); Fri, 2 Oct 2020 04:32:35 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:41128 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725961AbgJBIcf (ORCPT ); Fri, 2 Oct 2020 04:32:35 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1601627553; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=HsKbNhW6JyOvMMjFKexiqV08EYNocTJhCoLVMa7DgIE=; b=KCmB2Loiww0GOii8DG3gVpmEbZxkBaZOQ02wfIOW6A1jwM9e9rQbFiA2yQyuXVE0GyIxkR Q8jz/AhOnUEHFn73X885O9pwKXCyy9gsEUY6z2WdFQaf2SfM39N7KgIB7M6TYxAPLVlE+K 9KAhyaSu9bBHEqBKUDWfQyZHONVqRO0mxtDFR82jTaV8E1vz/f1H0GoibZdGfoVh+Lzz1i DV16j1QC+8Aa4dWJ7BpAT/3o5y1DIcSlsQoSBbK8pv0khmNTcccYFu7UHD6xjnlN3cL4dR 1YMUqaENl1gHfxcuSsZoZJLUzPusDtYXhtzavYRu9HsDwShAWuBRN4/XjIZcpA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1601627553; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=HsKbNhW6JyOvMMjFKexiqV08EYNocTJhCoLVMa7DgIE=; b=JGKS+1g+uj2Yxl07TKYt8CCkuIJjovYPDzqG1I8oSy2opzXLr6TwMk5/O8vrAS+TEu/dqm 6bsqbF/+pMJAgjBg== To: Hillf Danton Cc: Hillf Danton , Petr Mladek , linux-kernel@vger.kernel.org, tj@kernel.org, akpm@linux-foundation.org, Peter Zijlstra , Zqiang Subject: Re: [RFC PATCH] kthread: do not modify running work In-Reply-To: <20201002023412.2276-1-hdanton@sina.com> References: <20200926040426.11936-1-hdanton@sina.com> <20201001095151.5640-1-hdanton@sina.com> <20201002023412.2276-1-hdanton@sina.com> Date: Fri, 02 Oct 2020 10:32:32 +0200 Message-ID: <877ds9do4f.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 02 2020 at 10:34, Hillf Danton wrote: > On Thu, 01 Oct 2020 15:59:38 +0200 Thomas Gleixner wrote: >> On Thu, Oct 01 2020 at 17:51, Hillf Danton wrote: >> Aside of that it's pretty irrelevant whether there is a user at the >> moment which reschedules work from the callback or not. >> >> It's something which needs to work because its possible from regular >> work queues as well and makes a lot of sense. > > https://lore.kernel.org/lkml/87eemheay8.fsf@nanos.tec.linutronix.de/ That's a completely different thing, really. This adds new functionality without users and exports it. kthread work is modeled after workqueue to address specific needs. delayed work can be rescheduled from the callback and all variants of timers support rearming the timer from the callback as well. So having a consistent behaviour accross all these facilities makes absolutely sense and I don't agree with your sentiment in the changelog at all. Just because it does not make sense to you is not a justification for making stuff inconsistent. You still have not provided a technical reason why this change is needed. Thanks, tglx