From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B9B5C5B578 for ; Wed, 3 Jul 2019 21:30:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 23D4921882 for ; Wed, 3 Jul 2019 21:30:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=permerror (0-bit key) header.d=prgmr.com header.i=@prgmr.com header.b="lYJSnzK5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727256AbfGCVaa (ORCPT ); Wed, 3 Jul 2019 17:30:30 -0400 Received: from mail.prgmr.com ([71.19.149.6]:57062 "EHLO mail.prgmr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726902AbfGCVaa (ORCPT ); Wed, 3 Jul 2019 17:30:30 -0400 Received: from turtle.mx (96-92-68-116-static.hfc.comcastbusiness.net [96.92.68.116]) (Authenticated sender: adp) by mail.prgmr.com (Postfix) with ESMTPSA id 1C29872008D for ; Wed, 3 Jul 2019 22:27:29 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.prgmr.com 1C29872008D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=prgmr.com; s=default; t=1562207249; bh=xtvcBkhZQMHtrCmE/920LkbkfaUDBJvo8ELcMPK895M=; h=Date:From:To:Subject:References:In-Reply-To:From; b=lYJSnzK5uQOlPGXfKfDgQMN6wEP9dNZ60GS//8lz0lus9u1OtHSt1uhLJmbtBPi9i McuT8vdi7HTlJ4oKTeHlPIVJHcLxxBmGNugV9RV2DRV39DK7TM4fp4v7jNITaXeuZ9 Vv83t58uwBehUM38zSgVdebmT8kHsALD59pLfCnI= Received: (qmail 22989 invoked by uid 1353); 3 Jul 2019 21:32:21 -0000 Date: Wed, 3 Jul 2019 15:32:21 -0600 From: Alan Post To: linux-nfs Subject: Re: User process NFS write hang in wait_on_commit with kworker Message-ID: <20190703213221.GB4158@turtle.email> References: <20190618000613.GR4158@turtle.email> <6DE07E49-D450-4BF7-BC61-0973A14CD81B@redhat.com> <20190619000746.GT4158@turtle.email> <25608EB2-87F0-4196-BEF9-8AB8FC72270B@redhat.com> <20190621204723.GU4158@turtle.email> <20190628183324.GJ4158@turtle.email> <35045385-2C77-4BA0-8641-2AE4E73E04A4@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <35045385-2C77-4BA0-8641-2AE4E73E04A4@redhat.com> Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Tue, Jul 02, 2019 at 05:55:10AM -0400, Benjamin Coddington wrote: > > As far as I understand it, for a particular xid, there should be a > > call and a reply. The approach I took then was to pull out these > > fields from my capture and ignore RPC calls where both are present > > in my capture. It seems this is simplistic, as the number of RPC > > calls I have without an attendant reply isn't lining up with my > > incident window. > > Does your capture report dropped packets? If so, maybe you need to increase > the capture buffer. > I'm not certain, but I do have a capture on both the NFS server and the NFS client--comparing them would show me if I was under most circumstances. Good catch. > > In one example, I have a series of READ calls which cease > > generating RPC reply messages as the offset for the file continues > > to increases. After a couple/few dozen messages, the RPC replies > > continue as they were. Is there a normal or routine explanation > > for this? > > > > RFC 5531 and the NetworkTracing page on wiki.linux-nfs.org have > > been quite helpful bringing me up to speed. If any of you have > > advice or guidance or can clarify my understanding of how the > > call/reply RPC mechanism works I appreciate it. > > Seems like you understand it. Do you have specific questions? > Is it true that for each RPC call there is an RPC reply with the same xid? Is it a-priori an error if an otherwise correct RPC call is not eventually paired with an RPC reply? Thank you, -A -- Alan Post | Xen VPS hosting for the technically adept PO Box 61688 | Sunnyvale, CA 94088-1681 | https://prgmr.com/ email: adp@prgmr.com