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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 52CF9C4743E for ; Tue, 8 Jun 2021 17:20:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 33C326135D for ; Tue, 8 Jun 2021 17:20:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233158AbhFHRWL (ORCPT ); Tue, 8 Jun 2021 13:22:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41070 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233005AbhFHRWK (ORCPT ); Tue, 8 Jun 2021 13:22:10 -0400 Received: from fieldses.org (fieldses.org [IPv6:2600:3c00:e000:2f7::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 162ABC061574 for ; Tue, 8 Jun 2021 10:20:16 -0700 (PDT) Received: by fieldses.org (Postfix, from userid 2815) id 9C36D685B; Tue, 8 Jun 2021 13:20:15 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.11.0 fieldses.org 9C36D685B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fieldses.org; s=default; t=1623172815; bh=2hQ+IhZOkW/0IERB/C1JhYCR/JFt50N0MUYyTTPmzUk=; h=Date:To:Cc:Subject:References:In-Reply-To:From:From; b=Sk830VBRLQT7h0r/ezL5Ysrt6IqvmmTjGHEcbYCQaelenfkxspK/qiqwCmAasaA5G QDlwX+2vwCytqt3rzgdB65EPhRsA0U8wk+f9xWOOToW3cO75Aqdlh9VD0BmfSSCflH G3Gj3RgkhOgAMK8sdpCRaWt1QQoLZB6tcIMONC3Q= Date: Tue, 8 Jun 2021 13:20:15 -0400 To: Frank van der Linden Cc: Wang Yugui , linux-nfs@vger.kernel.org Subject: Re: nfsd dead loop when xfstests generic/531 Message-ID: <20210608172015.GB22685@fieldses.org> References: <20210531125948.2D37.409509F4@e16-tech.com> <20210601165535.GA3102@dev-dsk-fllinden-2c-d7720709.us-west-2.amazon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210601165535.GA3102@dev-dsk-fllinden-2c-d7720709.us-west-2.amazon.com> User-Agent: Mutt/1.5.21 (2010-09-15) From: bfields@fieldses.org (J. Bruce Fields) Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Tue, Jun 01, 2021 at 04:55:35PM +0000, Frank van der Linden wrote: > On Mon, May 31, 2021 at 12:59:51PM +0800, Wang Yugui wrote: > > > > > > Hi, > > > > nfsd dead loop when xfstests generic/531 > > > > linux kernel of nfs server: 5.10.41 > > linux kernel of nfs client: 5.10.41 > > > > > > nfsd dead loop when xfstests generic/531 > > > > linux kernel of nfs server: 5.10.41 > > linux kernel of nfs client: 5.10.41 > > This is a known issue. generic/531 opens a large number of files, causing > the nfsd file cache code to walk a very long LRU list of open files. For > v4, there will be a lot of long term opens (because of the OPEN call), > and they all end up on that list. > > So, the basic issue is, that the nfsd file cache is a good match for > v3 semantics, but less so for v4 semantics. > > I posted an experimental patch to work around the issue: > > https://lore.kernel.org/linux-nfs/20201020183718.14618-4-trondmy@kernel.org/T/#m869aa427f125afee2af9a89d569c6b98e12e516f > > The rhashtable patch has issues, so disregard that one, but the other one > is a basic fix for this issue. It has one other issue that I noticed (refcount > error), but that is easily fixed. > > I should update the patch and formally post it.. That would be great. --b.