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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 76BD2C433DF for ; Thu, 21 May 2020 10:11:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 412A5207D3 for ; Thu, 21 May 2020 10:11:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="nC1DRrF+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728461AbgEUKLC (ORCPT ); Thu, 21 May 2020 06:11:02 -0400 Received: from merlin.infradead.org ([205.233.59.134]:34896 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728292AbgEUKLC (ORCPT ); Thu, 21 May 2020 06:11:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=MXiJifaZtgfEcmcUxJdE198Idg9c7DGrSBxW7026Ud4=; b=nC1DRrF+mF+dnRH1p/ebtgPAQ6 gLxrv/pcapO3aCrkJVcaJVtPVaC+jAJjCMtnpSvBqpJBOc0X5jmeH0P7Dz+PJujoqZ0/n1EuPCmVE UruNDUgUlUhRG4TMAks1Hl4B8xRZvg9oKJOxkBFEnXQwgVVusDkuu5yKb7Pc4+qSY7etSICVJUoV8 6d/jt2Fg82ppC/YN3CfLR7iV3Tj5Zh2J6CO6rDD+FiBcVIfP8RoHBZOAA/1/vJkdbvCxmm+W3fcGf N+MX1SOGps9gOy91OLdUtAozqYX4lguWc1lDOxpfYXDe4DVL7sp4QbBgURjaCiNAdZAE5QeT2zJGx vaaa5skw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jbiA6-0001kN-P5; Thu, 21 May 2020 10:10:50 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id EEBE1304123; Thu, 21 May 2020 12:10:47 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id D7C732B7DA1F7; Thu, 21 May 2020 12:10:47 +0200 (CEST) Date: Thu, 21 May 2020 12:10:47 +0200 From: Peter Zijlstra To: Frederic Weisbecker Cc: Qian Cai , "Paul E. McKenney" , Linux Kernel Mailing List , Thomas Gleixner , Michael Ellerman , linuxppc-dev , Borislav Petkov Subject: Re: Endless soft-lockups for compiling workload since next-20200519 Message-ID: <20200521101047.GH325280@hirez.programming.kicks-ass.net> References: <20200520125056.GC325280@hirez.programming.kicks-ass.net> <20200521004035.GA15455@lenoir> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200521004035.GA15455@lenoir> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 21, 2020 at 02:40:36AM +0200, Frederic Weisbecker wrote: > atomic_fetch_or(...., nohz_flags(0)) > softirq() { #VMEXIT or anything that could stop a CPU for a while > run_rebalance_domain() { > nohz_idle_balance() { > atomic_andnot(NOHZ_KICK_MASK, nohz_flag(0)) I'm an idiot and didn't have enough wake-up-juice; I missed that andnot clearing the flag again. Yes, fun fun fun..