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=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 82300C4320A for ; Tue, 10 Aug 2021 00:50:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5A4DA61004 for ; Tue, 10 Aug 2021 00:50:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236230AbhHJAul (ORCPT ); Mon, 9 Aug 2021 20:50:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45512 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233500AbhHJAuk (ORCPT ); Mon, 9 Aug 2021 20:50:40 -0400 Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C0AD8C0613D3 for ; Mon, 9 Aug 2021 17:50:19 -0700 (PDT) Received: by mail-pl1-x62a.google.com with SMTP id c16so18646207plh.7 for ; Mon, 09 Aug 2021 17:50:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=/5H1fmHVLJ8WPclm4fIdOK4R2sVXaDazjuNGVOpqFUY=; b=MMYMcDfGKK+lCN8x4/UuMUE1bxkQamcV7FBPw0qdo1Cp2P42c+1HhAkvmip/bUhxYH vvxmTKRIUZg+0gv7eKtiHHpBpYuxkviZyiALvujHwyAUYRH9Jf1S8j7Tt1bzv93buLL3 gXIHHkgRAIwYrBd4UgiuXXFpgKX3tr/8C2xxnMWo6daEkz89gY2owYJHRFJ+Jhg/pVKm msFp0BsjgpVJg4GPGsidENfc/ayMoJopr+xUqdHoMgV+n7P5CE30e0FG8dYTW3njhSrg iv6y8BUPyL5tRc7CDA5HH6JizP6c/nYTXtq/RA96Qe5AL11MP1UyTtlFDW0IBYKvAp2R EV1w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=/5H1fmHVLJ8WPclm4fIdOK4R2sVXaDazjuNGVOpqFUY=; b=lw84Q8ewbJ5/14iIC/xlfyl7wRQLjN1cbshQYzlt0lDBBRrSqgHnZDTcytX1P5L3yf YG1TCnWjlWo9XNjYEPg1DmgZRqH3bmIPxZS0pV1KQegftgIzHPnaoFYj6Fxa71dgpA5Y KbnCaXNRqvX9H4CnWgOXAK4+3jixcWbffnBWZbRdpmqFtLKPu/czQb8gWYmYgdzaQkUi +jatzTnXJhUy35gWbl696i15ZCiY/PkC4zRIyddzrR5ewSwc8IwtyvkyRolOxVOcN6hf 7slXeZaI1q3Jo4KtO7TF4nJD4LuhSBr6VB3M0yQSiQL0wpoYpLIBvQWukLIcTi82LrrS gBCQ== X-Gm-Message-State: AOAM531IwHbowtsbLYUZmncRgQT3W7xRkjHBAznOISC8muBR8BF0bP2Y aAE07rczNKAJ7xRFCSFCFiNafD2wCSnMu/da+pHx5mF8EEUwSQ== X-Google-Smtp-Source: ABdhPJy4cG2ufTNuuNWIItf2EVFRugw00GYkI/OzhZ0pn8qU35jVRKUZvMFODs1llYDwdrBvkfstYW0AlvYhi5aSB6w= X-Received: by 2002:a17:90a:509:: with SMTP id h9mr1973169pjh.71.1628556619032; Mon, 09 Aug 2021 17:50:19 -0700 (PDT) MIME-Version: 1.0 References: <162846730406.22632.14734595494457390936@noble.neil.brown.name> In-Reply-To: From: Mike Javorski Date: Mon, 9 Aug 2021 17:50:08 -0700 Message-ID: Subject: Re: NFS server regression in kernel 5.13 (tested w/ 5.13.9) To: linux-nfs@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Managed to get the rpcdebug info for some freezes today. I had a loop running to call the rpcbind command that Neil provided and then sleep for 2 seconds. Each triggering event was the opening of a new video file (I was shuffling through files with mpv). I haven't managed to get a tcp capture yet trying to get one that isn't too massive, but the timing is tricky, and this doesn't happen every time. ----------------------------- [31229.965368] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31229.965370] 44224 c801 0 8c478d70 2473aa3b 15395 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31229.965411] 44225 c801 0 8c478d70 a7d3b9b8 15395 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31231.966982] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31231.966986] 44224 c801 0 8c478d70 2473aa3b 14795 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31231.967027] 44225 c801 0 8c478d70 a7d3b9b8 14795 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31233.968741] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31233.968745] 44224 c801 0 8c478d70 2473aa3b 14194 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31233.968787] 44225 c801 0 8c478d70 a7d3b9b8 14194 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending ----------------------------- [31292.534529] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31292.534530] 45744 c801 0 8c478d70 2473aa3b 15340 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31292.534554] 45745 c801 0 8c478d70 50cbef7b 15342 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31294.536203] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31294.536206] 45744 c801 0 8c478d70 2473aa3b 14740 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31294.536232] 45745 c801 0 8c478d70 50cbef7b 14742 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31296.537826] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31296.537830] 45744 c801 0 8c478d70 2473aa3b 14139 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31296.537871] 45745 c801 0 8c478d70 50cbef7b 14141 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31298.539474] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31298.539478] 45744 c801 0 8c478d70 2473aa3b 13539 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31298.539522] 45745 c801 0 8c478d70 50cbef7b 13541 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31300.541040] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31300.541044] 46048 c801 0 8c478d70 50cbef7b 17965 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31300.541108] 46049 c801 0 8c478d70 2473aa3b 17965 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31302.542632] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31302.542635] 46922 c801 0 8c478d70 50cbef7b 18000 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending --------------------------- [31375.046020] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31375.046022] 47336 c801 0 8c478d70 cebaa9a6 15964 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31375.046048] 47337 c801 0 8c478d70 f7145d4d 15964 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31377.047361] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31377.047365] 47336 c801 0 8c478d70 cebaa9a6 15364 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31377.047406] 47337 c801 0 8c478d70 f7145d4d 15364 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31379.048801] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31379.048805] 47336 c801 0 8c478d70 cebaa9a6 14764 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31379.048845] 47337 c801 0 8c478d70 f7145d4d 14764 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31381.050376] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31381.050380] 47336 c801 0 8c478d70 cebaa9a6 14163 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31381.050421] 47337 c801 0 8c478d70 f7145d4d 14163 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31383.051746] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31383.051749] 47336 c801 0 8c478d70 cebaa9a6 13563 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31383.051775] 47337 c801 0 8c478d70 f7145d4d 13563 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31385.053182] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31385.053185] 47342 c801 0 8c478d70 f7145d4d 17980 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31387.054422] -pid- flgs status -client- --rqstp- -timeout ---ops-- [31387.054426] 47818 c801 0 8c478d70 f7145d4d 17761 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending [31387.054467] 47819 c801 0 8c478d70 cebaa9a6 17762 8531859 nfsv4 READ a:call_status [sunrpc] q:xprt_pending - mike On Sun, Aug 8, 2021 at 5:28 PM Mike Javorski wrote: > > Appreciate the insights Neil. I will make an attempt to > trigger/capture the fault if I can. > > - mike > > On Sun, Aug 8, 2021 at 5:01 PM NeilBrown wrote: > > > > On Mon, 09 Aug 2021, Mike Javorski wrote: > > > I have been experiencing nfs file access hangs with multiple release > > > versions of the 5.13.x linux kernel. In each case, all file transfers > > > freeze for 5-10 seconds and then resume. This seems worse when reading > > > through many files sequentially. > > > > A particularly useful debugging tool for NFS freezes is to run > > > > rpcdebug -m rpc -c all > > > > while the system appears frozen. As you only have a 5-10 second window > > this might be tricky. > > Setting or clearing debug flags in the rpc module (whether they are > > already set or not) has a side effect if listing all RPC "tasks" which a > > waiting for a reply. Seeing that task list can often be useful. > > > > The task list appears in "dmesg" output. If there are not tasks > > waiting, nothing will be written which might lead you to think it didn't > > work. > > > > As Chuck hinted, tcpdump is invaluable for this sort of problem. > > tcpdump -s 0 -w /tmp/somefile.pcap port 2049 > > > > will capture NFS traffic. If this can start before a hang, and finish > > after, it may contain useful information. Doing that in a way that > > doesn't create an enormous file might be a challenge. It would help if > > you found a way trigger the problem. Take note of the circumstances > > when it seems to happen the most. If you can only produce a large file, > > we can probably still work with it. > > tshark -r /tmp/somefile.pcap > > will report the capture one line per packet. You can look for the > > appropriate timestamp, note the frame numbers, and use "editcap" > > to extract a suitable range of packets. > > > > NeilBrown > > > > > > > > > > My server: > > > - Archlinux w/ a distribution provided kernel package > > > - filesystems exported with "rw,sync,no_subtree_check,insecure" options > > > > > > Client: > > > - Archlinux w/ latest distribution provided kernel (5.13.9-arch1-1 at writing) > > > - nfs mounted via /net autofs with "soft,nodev,nosuid" options > > > (ver=4.2 is indicated in mount) > > > > > > I have tried the 5.13.x kernel several times since the first arch > > > release (most recently with 5.13.9-arch1-1), all with similar results. > > > Each time, I am forced to downgrade the linux package to a 5.12.x > > > kernel (5.12.15-arch1 as of writing) to clear up the transfer issues > > > and stabilize performance. No other changes are made between tests. I > > > have confirmed the freezing behavior using both ext4 and btrfs > > > filesystems exported from this server. > > > > > > At this point I would appreciate some guidance in what to provide in > > > order to diagnose and resolve this issue. I don't have a lot of kernel > > > debugging experience, so instruction would be helpful. > > > > > > - mike > > > > > >