From owner-freebsd-net@FreeBSD.ORG Fri Aug 26 01:43:13 2011 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E72891065670 for ; Fri, 26 Aug 2011 01:43:13 +0000 (UTC) (envelope-from artemb@gmail.com) Received: from mail-yw0-f54.google.com (mail-yw0-f54.google.com [209.85.213.54]) by mx1.freebsd.org (Postfix) with ESMTP id A5FAD8FC0A for ; Fri, 26 Aug 2011 01:43:13 +0000 (UTC) Received: by ywo32 with SMTP id 32so2748031ywo.13 for ; Thu, 25 Aug 2011 18:43:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=UTQdMYIpUYqBSSHq0mXKwresGV+1hexVC1UkbrwpsY0=; b=KgcwgZr1XMKP31r4BBAM4DfiwG2XYX+UgPnqnjlhBwq1QftdybF+B0ovTK58pAhS33 PETy9CqK/8YeCDH/cgO5gxc4aTmxuEvtbpbjLkZaOHOfU5CmdErHdtuL3B9G90CC9bAt TGpKVRZ7X5sUgccVdCAHNhgUM0l9cPg7ISeqA= MIME-Version: 1.0 Received: by 10.236.37.230 with SMTP id y66mr3132254yha.10.1314322992838; Thu, 25 Aug 2011 18:43:12 -0700 (PDT) Sender: artemb@gmail.com Received: by 10.236.102.147 with HTTP; Thu, 25 Aug 2011 18:43:12 -0700 (PDT) In-Reply-To: <1499650185.371230.1314321868068.JavaMail.root@erie.cs.uoguelph.ca> References: <1499650185.371230.1314321868068.JavaMail.root@erie.cs.uoguelph.ca> Date: Thu, 25 Aug 2011 18:43:12 -0700 X-Google-Sender-Auth: bybdCR29mhMinM-TEYHLApU4qj8 Message-ID: From: Artem Belevich To: Rick Macklem Content-Type: text/plain; charset=ISO-8859-1 Cc: freebsd-net@freebsd.org, Martin Birgmeier Subject: Re: amd + NFS reconnect = ICMP storm + unkillable process. X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Aug 2011 01:43:14 -0000 On Thu, Aug 25, 2011 at 6:24 PM, Rick Macklem wrote: > Btw, I fixed exactly the same issue for the TCP code (clnt_vc.c) in > r221127, so I wouldn't be surprised if the UDP code suffers the same The code in clnt_vc.c was exactly what made me wonder about treatment of ERESTART. > problem. I'll take a look at your patch tomorrow. You could also try > a TCP mount and see if the problem goes away. (For TCP on a pre-r221127 > system, the symptom would be a client thread looping in the kernel in > "R" state.) In my case the process was also stuck in unkillable running state because the process never returns from the syscall. Unfortunately amd itself seems to handle NFS requests for its own top-level mountpoints only via UDP. At least I haven't found a way to do so without hacking rather convoluted amd code. > I'll look tomorrow, but it sounds like you've figured it out. Looks like > a good catch to me at this point, rick Let me know if you're OK with the patch and I'll commit to head and MFC it to stable/8. --Artem