From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50476) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y0WCA-0007om-4L for qemu-devel@nongnu.org; Mon, 15 Dec 2014 09:00:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Y0WC3-0006jm-SI for qemu-devel@nongnu.org; Mon, 15 Dec 2014 09:00:18 -0500 Received: from mx1.redhat.com ([209.132.183.28]:37713) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y0WC3-0006j1-MB for qemu-devel@nongnu.org; Mon, 15 Dec 2014 09:00:11 -0500 Date: Mon, 15 Dec 2014 09:00:06 -0500 From: Luiz Capitulino Message-ID: <20141215090006.636b5d3e@redhat.com> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] QMP unix socket randomly returning -EAGAIN List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mohammed Gamal Cc: Anshul Makkar , Mikhail Sennikovskii , qemu-devel@nongnu.org, Eduardo Otubo , Elmar Gerdes On Fri, 12 Dec 2014 16:54:39 +0100 Mohammed Gamal wrote: > Hi, > > We are experiencing random errors with communication with VMs with QMP via > unix sockets. At some moment of time the QMP socket keeps on returning > -EAGAIN and never recovering from this state unless the qemu process is > stopped then started. This socket hickup happens specfically when > connecting to the socket or receiving a response from it. > > I suspected that this might be caused by the guest hanging on some IO or > being unresponsive for any reason, but the VMs in question were not > unresponsive at these times and could be accessed via VNC or SSH normally. > I've seen this on machines runnnig qemu 1.0,1 1.2.0 and 2.0.0 > > I am suspecting it might be a bug in the monitor code, but I couldn't reach > anything tangible. Any ideas what might be causing this? No. Can you provide a reproducer?