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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B44B4C433EF for ; Wed, 20 Oct 2021 06:32:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8946360E9B for ; Wed, 20 Oct 2021 06:32:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229822AbhJTGes (ORCPT ); Wed, 20 Oct 2021 02:34:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55024 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229591AbhJTGer (ORCPT ); Wed, 20 Oct 2021 02:34:47 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 278F5C06161C for ; Tue, 19 Oct 2021 23:32:33 -0700 (PDT) Date: Wed, 20 Oct 2021 08:32:30 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1634711551; 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=n2EzcaJsHoclkkFmC9co6PrDzTCp/HjVc2eV8xmo/iY=; b=16opjXvsmp0cBuE8fy2YEPxnTZ4MCnsTx3EQ21GN0kpGG2EP6swrV/Rl9It/ANs0Bkfq0I jgDucSkAHnwxSfwbVGzagPrdEeKz1t7B47YqMqE+B9ct27Z0NVj2RY764P84DPF//I+tAx bDJNnMshblJTo0XqD68nUYPLSmIH/skDN+sL70w6+CIocGhBcGMYYJ+acgKIwEFlJbP8YF kKgeT3/KzasmdcUB2OZ36DwZ5HNu5VpoMyPlBKst8bAOXQp8o2p7DShN0K8P6vFNm2KCdz /vpkYI0CLCTL2NJ3vw065VDOjYIqVfzOCwzPk8P8QAPOuD5EfdmMyWp86mQVag== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1634711551; 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=n2EzcaJsHoclkkFmC9co6PrDzTCp/HjVc2eV8xmo/iY=; b=lcFZBaJ5B5xZjxVVFPqboacLDk5AF0mRERpaD/+SWV2+Mt60h71W6njcoFyadIlLfcpQpc fK50/T74Z2rytLCg== From: Sebastian Andrzej Siewior To: Peter Zijlstra Cc: syzbot , bristot@redhat.com, bsegall@google.com, dietmar.eggemann@arm.com, gor@linux.ibm.com, jgross@suse.com, juri.lelli@redhat.com, linux-kernel@vger.kernel.org, mgorman@suse.de, mingo@kernel.org, mingo@redhat.com, namit@vmware.com, rdunlap@infradead.org, rostedt@goodmis.org, syzkaller-bugs@googlegroups.com, vincent.guittot@linaro.org Subject: Re: [syzbot] possible deadlock in wake_up_all_idle_cpus Message-ID: <20211020063230.r3cm2ubpmps3lcgo@linutronix.de> References: <000000000000cf252605ce67014a@google.com> <00000000000041567305ce80b8af@google.com> <20211019190811.ubam63tfv33c7lmx@linutronix.de> <20211019202741.GN174703@worktop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20211019202741.GN174703@worktop.programming.kicks-ass.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-10-19 22:27:41 [+0200], Peter Zijlstra wrote: > On Tue, Oct 19, 2021 at 09:08:11PM +0200, Sebastian Andrzej Siewior wrote: > > Does this do anything useful? > > I've got https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/commit/?h=sched/core&id=3dfddc2f0f76525218dd2d0c8725d9f21dd411e2 > > There's like 3 or 4 threads on this :/ I just got a tested-by on that. Yeah I saw a few emails and wanted to talk to the bot, assuming it would keep quiet then. for_each_possible_cpu looks big but is probably equal to online_cpu in most cases. Thanks ;) Sebastian