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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 52BF2C4361B for ; Mon, 7 Dec 2020 14:01:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A4D923444 for ; Mon, 7 Dec 2020 14:01:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727264AbgLGOBY (ORCPT ); Mon, 7 Dec 2020 09:01:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35678 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726261AbgLGOBX (ORCPT ); Mon, 7 Dec 2020 09:01:23 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 57492C0613D0 for ; Mon, 7 Dec 2020 06:00:43 -0800 (PST) Date: Mon, 7 Dec 2020 15:00:40 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1607349641; 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=EpLte4OfQdYM2bvhiOAl1LeQjrSrqFUqkKhrRrW07gY=; b=JtS7Ylt++U4yYFnk/5jb5Zwst/Tn7BnkjqIbKBhQf/8q4gpuCpfZnKuMQjZV0EdrdjY2Vi EnKb7SMjWY0JElsw0QIwLk68m08z6FsAKPpeSjIpeGGZJ58irRTFdfpy1IwaWAx/WimnaT mWLyGedG+uMfA9pLMnQpwUPRN8SQzeE6hM+VpfuJsLHpoz+lqZUJkKNgMbeKZ0PbpYUOJy RIbvWGF/YaAAmWOMvOMddr5Ga7W239QLnVRCtj2GzQrdda171rRg2xO/cFRZsYec3Gtz/W lyoH0dj4LG0FOOGLcsAl3rw5zXW4ARyEqEPcxvVWbbAirDMMSPcDwPfA1suNAA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1607349641; 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=EpLte4OfQdYM2bvhiOAl1LeQjrSrqFUqkKhrRrW07gY=; b=PfjhlqPhY/T17mp1rwFrfV4BheK9NiZ2O9F9c+hUx8WgVnzKysf22PxEpS6v+rI9qTwzY5 eV7gHx57gLf7blBw== From: Sebastian Andrzej Siewior To: Peter Zijlstra Cc: Thomas Gleixner , LKML , Frederic Weisbecker , Paul McKenney Subject: Re: [patch V2 9/9] tasklets: Prevent kill/unlock_wait deadlock on RT Message-ID: <20201207140040.yrxsu4v4xz43szkk@linutronix.de> References: <20201204170151.960336698@linutronix.de> <20201204170805.627618080@linutronix.de> <20201207114743.GK3040@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20201207114743.GK3040@hirez.programming.kicks-ass.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-12-07 12:47:43 [+0100], Peter Zijlstra wrote: > On Fri, Dec 04, 2020 at 06:02:00PM +0100, Thomas Gleixner wrote: > > @@ -825,7 +848,20 @@ void tasklet_kill(struct tasklet_struct > > > > while (test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) { > > do { > > - yield(); > > } while (test_bit(TASKLET_STATE_SCHED, &t->state)); > > } > > tasklet_unlock_wait(t); > > > Egads... should we not start by doing something like this? So we keep the RT part as-is and replace the non-RT bits with this? Sebastian