From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Hill Subject: Re: Shutting down a VM with Kernel 4.14 will sometime hang and a reboot is the only way to recover. Date: Wed, 29 Nov 2017 14:13:28 -0500 Message-ID: References: <92c4f997-80db-fabf-98c8-fcb92da064a7@redhat.com> <7bd45f84-d07e-7fca-6ca3-07dededd092d@redhat.com> <29f8e09f-8920-52d0-02f4-c0fb779135ee@redhat.com> <9c912f3b-081c-8b02-17c8-453ebf36f42c@redhat.com> <10fe2b98-1e26-9539-9f49-0d01f8693e04@redhat.com> <6b41b4e5-6c0c-fce6-21fe-02dd8f550095@redhat.com> <634116a6-6338-4249-7d2d-430b654cc99c@redhat.com> <1f789868-7fda-3553-7078-3298873fb355@redhat.com> <918c4152-bcf9-b28c-0f54-f51d07d82bfc@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit To: Jason Wang , Paolo Bonzini , kvm@vger.kernel.org Return-path: Received: from mail-qk0-f176.google.com ([209.85.220.176]:43954 "EHLO mail-qk0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751443AbdK2TNb (ORCPT ); Wed, 29 Nov 2017 14:13:31 -0500 Received: by mail-qk0-f176.google.com with SMTP id j207so5801664qke.10 for ; Wed, 29 Nov 2017 11:13:31 -0800 (PST) In-Reply-To: <918c4152-bcf9-b28c-0f54-f51d07d82bfc@redhat.com> Content-Language: en-US Sender: kvm-owner@vger.kernel.org List-ID: On 2017-11-29 12:15 AM, Jason Wang wrote: > > > On 2017年11月29日 10:52, Dave Hill wrote: >>>> >>> >>> Thanks. Zerocopy is disabled by several distribution by default. For >>> upstream, the only reason to let it on is to hope more developers >>> can help and fix the issues. >>> >>> >> So I never hit this issue with previous kernel and this issue started >> happening with the v4.14-rc series. > > > Right, this still need to be investigated if it was introduced recently. > > Looking at git history, the only suspected commit is for 4.14 is > > commit 1e6f74536de08b5e50cf0e37e735911c2cef7c62 > Author: Willem de Bruijn > Date:   Fri Oct 6 13:22:31 2017 -0400 > >     vhost_net: do not stall on zerocopy depletion > > Maybe you can try to revert it and see. > > If it does not solve your issue, I suspect there's bug elsewhere that > cause a packet to be held for very long time. > >>   I'm using rawhide so perhaps this is why it isn't disabled by >> default but I have to mention it's an update of FC25 up to FC28 and >> it never got disabled. >> Perhaps it should be disabled in Fedora too if it's not the case... >> I'm not sure this is the place to discuss this ... is it? > > Probably not, but I guess Fedora tries to use new technology > aggressively. > > Thanks I can revert that commit in 4.15-rc1 but I can't find it in 4.14.2 ...  Is there another commit that could affect this ?