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=-3.0 required=3.0 tests=BAYES_00,DKIM_ADSP_ALL, 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 CADF3C433E0 for ; Fri, 31 Jul 2020 22:36:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A30C122B3F for ; Fri, 31 Jul 2020 22:36:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=wq.cz header.i=@wq.cz header.b="iE/jTz13"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=wq.cz header.i=@wq.cz header.b="qFT0mjK1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726281AbgGaWgH (ORCPT ); Fri, 31 Jul 2020 18:36:07 -0400 Received: from srw1.wq.cz ([80.92.240.241]:51696 "EHLO srw1.wq.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726119AbgGaWgH (ORCPT ); Fri, 31 Jul 2020 18:36:07 -0400 X-Greylist: delayed 1815 seconds by postgrey-1.27 at vger.kernel.org; Fri, 31 Jul 2020 18:36:06 EDT DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=wq.cz; s=default; 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:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=+tv/ptYOI0F1xH3HAd77UevlqvOcTsLS/bdj/0Dq7DU=; b=iE/jTz13e+dubZq6E1p3JgD3yT iAbg6SsImNdLngKgDMhFe/usQT45Ra3J8Ry1bTC4t8gyzKOMkdWwcsGdTTG+/qtTrVPCOghCYVQtL /Roh0Ih5TdI1hyxGbfkA/qEE/f+l0xqZmhFm/ht7sVurD0mlMUhrplvAV5N9obwl/0Fo=; Received: from fw.wq.cz ([185.71.40.210] helo=msc.wq.cz) by srw1.wq.cz with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1k1d9v-00087U-Tc; Sat, 01 Aug 2020 00:05:48 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=wq.cz; s=ntm; 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:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=+tv/ptYOI0F1xH3HAd77UevlqvOcTsLS/bdj/0Dq7DU=; b=qFT0mjK1sD0ds4o0mYzxqBpy4S MU95qJbHWwWoM/C5fLdo8utOB2Ukz4gGTK+85bt0r4npbrQ70tXOr/Sxj68iZn3iEz+d+472dWK+B r/MDUnjzE86ET/R5v4RkygPq6NLjYitO6D2u9OcgZW2ONAzJZK7RqZ88VX0quW1DmzqA=; Received: from milon by msc.wq.cz with local (Exim 4.92) (envelope-from ) id 1k1d9v-0007LD-O5; Sat, 01 Aug 2020 00:05:47 +0200 Date: Sat, 1 Aug 2020 00:05:47 +0200 From: Milan Kocian To: Alexandru Elisei Cc: kvm@vger.kernel.org, julien.thierry.kdev@gmail.com, will@kernel.org, jean-philippe@linaro.org, andre.przywara@arm.com, Anvay Virkar Subject: Re: [PATCH kvmtool] virtio: Fix ordering of virt_queue__should_signal() Message-ID: <20200731220547.GD7810@msc.wq.cz> References: <20200731101427.16284-1-alexandru.elisei@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200731101427.16284-1-alexandru.elisei@arm.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hello, > I *think* this also fixes the VM hang reported in [1], where several > processes in the guest were stuck in uninterruptible sleep. I am not > familiar with the block layer, but my theory is that the threads were stuck > in wait_for_completion_io(), from blk_execute_rq() executing a flush > request. It would be great if Milan could give this patch a spin and see if > the problem goes away. Don't know how reproducible it is though. > > [1] https://www.spinics.net/lists/kvm/msg204543.html > Okay, I will test it but it takes some time. Because I migrated to the qemu due this problem :-) so I need to prepare new environment. And because the problem happens randomly. My environment can run days/few weeks without this problem. Thanks. Best regards. -- Milan Kocian