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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3A108C433EF for ; Wed, 11 May 2022 12:38:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242555AbiEKMiP (ORCPT ); Wed, 11 May 2022 08:38:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44180 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242499AbiEKMiM (ORCPT ); Wed, 11 May 2022 08:38:12 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6BEDE22EA5F; Wed, 11 May 2022 05:38:11 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 075D5B82219; Wed, 11 May 2022 12:38:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 598DFC340F2; Wed, 11 May 2022 12:38:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1652272688; bh=gyTtKqGrdgmxpfgLM/JIRhyOctz/MqSDCYRh45Yfp+A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=2deGWEjFIg1VgIh1TKv9PzyymIsk0XV45P65/6KT+7fgWhx/q7J9Z93XxM0lgkI07 23oYRtnpPjgTC/vPze8yeriSL3XDwctV4KioqFkzfx6dPykma7d+doD/ho8cLanDT/ ebzYoRmFK85QBoksGCChCTVmfYHC+ERfFLMlwC6k= Date: Wed, 11 May 2022 14:38:05 +0200 From: Greg KH To: Wolfgang Walter Cc: stable@vger.kernel.org, Trond Myklebust , Chuck Lever , linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: 5.4.188 and later: massive performance regression with nfsd Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 11, 2022 at 12:03:13PM +0200, Wolfgang Walter wrote: > Hi, > > starting with 5.4.188 wie see a massive performance regression on our > nfs-server. It basically is serving requests very very slowly with cpu > utilization of 100% (with 5.4.187 and earlier it is 10%) so that it is > unusable as a fileserver. > > The culprit are commits (or one of it): > > c32f1041382a88b17da5736886da4a492353a1bb "nfsd: cleanup > nfsd_file_lru_dispose()" > 628adfa21815f74c04724abc85847f24b5dd1645 "nfsd: Containerise filecache > laundrette" > > (upstream 36ebbdb96b694dd9c6b25ad98f2bbd263d022b63 and > 9542e6a643fc69d528dfb3303f145719c61d3050) > > If I revert them in v5.4.192 the kernel works as before and performance is > ok again. > > I did not try to revert them one by one as any disruption of our nfs-server > is a severe problem for us and I'm not sure if they are related. > > 5.10 and 5.15 both always performed very badly on our nfs-server in a > similar way so we were stuck with 5.4. > > I now think this is because of 36ebbdb96b694dd9c6b25ad98f2bbd263d022b63 > and/or 9542e6a643fc69d528dfb3303f145719c61d3050 though I didn't tried to > revert them in 5.15 yet. Odds are 5.18-rc6 is also a problem? If so, I'll just wait for the fix to get into Linus's tree as this does not seem to be a stable-tree-only issue. thanks, greg k-h