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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53793C07E9D for ; Mon, 26 Sep 2022 14:37:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234950AbiIZOhb (ORCPT ); Mon, 26 Sep 2022 10:37:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59138 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234759AbiIZOg6 (ORCPT ); Mon, 26 Sep 2022 10:36:58 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E9C2164EA; Mon, 26 Sep 2022 05:56:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=9e5ZsFmEwqFgQJJWTznPDZKlyACAw4+tFf2Fsk0YUI4=; b=MyO0V+ZRwmf429N2b3uG/HRVUh FT5vAkpKajidvb0yBrBvav/7E/0A20CN8bVWgICAaTqQtNX3M8w2++EEM1w+AV8V4KZpD3u5LETB8 wHHldUhL/DnmDs4jn8B64LZwWM8EnRZ2ehf6HeYgcZhMCeqAyRkJrUekYf6IMyC4SWSYA3xaQo3BS Flvo4KDvCNoigiGhtR7SgmyP+Enhx5IsagftIHKfY3Faeb5y4Ip31VVGCFZGq1FHanbOtjXgodBFY Cv+ChVWrwug/70b3LpgCiWq8NzRA3G3iiy85a7UTGOKTvgDNf0AajL0tFUixgqu9L0sPdfwSJZcYx QIfupF4Q==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1ocneF-00G1fp-8A; Mon, 26 Sep 2022 12:55:47 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 306A7300A72; Mon, 26 Sep 2022 14:55:46 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 11B5D201E09E7; Mon, 26 Sep 2022 14:55:46 +0200 (CEST) Date: Mon, 26 Sep 2022 14:55:45 +0200 From: Peter Zijlstra To: Christian Borntraeger Cc: bigeasy@linutronix.de, dietmar.eggemann@arm.com, ebiederm@xmission.com, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, mgorman@suse.de, mingo@kernel.org, oleg@redhat.com, rjw@rjwysocki.net, rostedt@goodmis.org, tj@kernel.org, vincent.guittot@linaro.org, will@kernel.org, Marc Hartmayer , Amit Shah , "virtualization@lists.linux-foundation.org" Subject: Re: [PATCH v3 6/6] freezer,sched: Rewrite core freezer logic Message-ID: References: <20220822114649.055452969@infradead.org> <20220923072104.2013212-1-borntraeger@linux.ibm.com> <56576c3c-fe9b-59cf-95b8-158734320f24@linux.ibm.com> <436fa401-e113-0393-f47a-ed23890364d7@linux.ibm.com> <39dfc425-deff-2469-7bcb-4a0e177b31d1@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <39dfc425-deff-2469-7bcb-4a0e177b31d1@linux.ibm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 26, 2022 at 02:32:24PM +0200, Christian Borntraeger wrote: > diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c > index 9fa3c76a267f..e93df4f735fe 100644 > --- a/drivers/char/virtio_console.c > +++ b/drivers/char/virtio_console.c > @@ -790,7 +790,7 @@ static int wait_port_writable(struct port *port, bool nonblock) > if (nonblock) > return -EAGAIN; > - ret = wait_event_freezable(port->waitqueue, > + ret = wait_event_interruptible(port->waitqueue, > !will_write_block(port)); > if (ret < 0) > return ret; > > Does fix the problem. It's almost as if someone does try_to_wake_up(.state = TASK_FREEZABLE) -- which would be quite insane. Could you please test with something like the below on? I can boot that with KVM, but obviously I didn't suffer any weirdness to begin with :/ --- diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 4e6a6417211f..ef9ccfc3a8c0 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4051,6 +4051,8 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) unsigned long flags; int cpu, success = 0; + WARN_ON_ONCE(state & TASK_FREEZABLE); + preempt_disable(); if (p == current) { /*