From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44846) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WXr9Y-0004SD-Fn for qemu-devel@nongnu.org; Wed, 09 Apr 2014 07:58:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WXr9U-0005TX-0v for qemu-devel@nongnu.org; Wed, 09 Apr 2014 07:58:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:19308) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WXr9T-0005TO-Pn for qemu-devel@nongnu.org; Wed, 09 Apr 2014 07:58:47 -0400 Date: Wed, 9 Apr 2014 12:58:38 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20140409115837.GD2584@work-vm> References: <1396967377-6311-1-git-send-email-dgilbert@redhat.com> <20140408160811.GA2505@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH v4 1/1] Make qemu_peek_buffer loop until it gets it's data List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: ???? Cc: quintela@redhat.com, qemu-devel@nongnu.org, armbru@redhat.com * ???? (chenliang0016@icloud.com) wrote: > > > * ???? (chenliang0016@icloud.com) wrote: > >> > >> ?? 2014??4??8????????10:29??Dr. David Alan Gilbert (git) ?????? > >> > >>> From: "Dr. David Alan Gilbert" > >>> > >>> Make qemu_peek_buffer repeatedly call fill_buffer until it gets > >>> all the data it requires, or until there is an error. > >>> > >>> At the moment, qemu_peek_buffer will try one qemu_fill_buffer if there > >>> isn't enough data waiting, however the kernel is entitled to return > >>> just a few bytes, and still leave qemu_peek_buffer with less bytes > >>> than it needed. I've seen this fail in a dev world, and I think it > >>> could theoretically fail in the peeking of the subsection headers in > >>> the current world. > >> hmm, I also have got some errors(infrequently). Maybe It is one point. > >> Could you show some messages about the error? > > > > I've only seen the errors in my visitor/ber world where I use the peek_buffer > > a lot more; but the one place it is used in the existing code is in > > the code to check if we have the start of a subsection; if that goes wrong > > I'm not sure what error would be produced. > > > > Dave > In my observation, error is more likely to happen if migration thread is blocked too long. > BTW, xbzrle and auto convergence are disable. What error do you see? Dave -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK