Return-Path: Received: from fieldses.org ([173.255.197.46]:49996 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751024AbdEaVAm (ORCPT ); Wed, 31 May 2017 17:00:42 -0400 Date: Wed, 31 May 2017 17:00:36 -0400 From: "bfields@fieldses.org" To: "Michael S. Tsirkin" Cc: hch , Trond Myklebust , "anna.schumaker@netapp.com" , "jlayton@poochiereds.net" , "linux-nfs@vger.kernel.org" , virtualization@lists.linux-foundation.org Subject: Re: remove function pointer casts and constify function tables Message-ID: <20170531210036.GD23526@fieldses.org> References: <20170513072557.GA14602@lst.de> <1494691819.31377.1.camel@primarydata.com> <20170515152134.GC24547@fieldses.org> <20170515154450.GA18630@lst.de> <20170523081159.GA19216@lst.de> <20170523122334.GA4298@fieldses.org> <20170526150839.GA4593@fieldses.org> <20170526150956.GB4593@fieldses.org> <20170526193133.GA9874@fieldses.org> <20170530200109-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20170530200109-mutt-send-email-mst@kernel.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, May 30, 2017 at 08:03:12PM +0300, Michael S. Tsirkin wrote: > On Fri, May 26, 2017 at 03:31:33PM -0400, bfields@fieldses.org wrote: > > Looks like the culprit is very likely d85b758f72b0 "virtio_net: fix > > support for small rings". > > > > After that patch, my NFS server VM stops responding to packets after a > > few minutes of testing. Before that patch, my server keeps working. > > > > --b. > > > So I think I know what caused this: looks like some hypervisors > aren't prepared to deal with a situation where packet size > becomes very small. > > But which hypervisors exactly? I'd like to know in order to detect these > and decide whether I blacklist bad ones or whitelist known-good ones. I'm running this under KVM on a Fedora 25 host (4.10.15-200.fc25.x86_64). Let me know if any more details about the setup would be useful. --b.