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 13112C433EF for ; Wed, 11 May 2022 10:09:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232831AbiEKKJc (ORCPT ); Wed, 11 May 2022 06:09:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50576 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241014AbiEKKJX (ORCPT ); Wed, 11 May 2022 06:09:23 -0400 X-Greylist: delayed 359 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Wed, 11 May 2022 03:09:13 PDT Received: from email.studentenwerk.mhn.de (dresden.studentenwerk.mhn.de [141.84.225.229]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B2C17A828; Wed, 11 May 2022 03:09:12 -0700 (PDT) Received: from mailhub.studentenwerk.mhn.de (mailhub.studentenwerk.mhn.de [127.0.0.1]) by email.studentenwerk.mhn.de (Postfix) with ESMTPS id 4Kyr7z1hfMzRhSb; Wed, 11 May 2022 12:03:11 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=stwm.de; s=stwm-20170627; t=1652263391; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=paHzsJSUUUK2l3doauEwUmwh24Gg8aqJ/AhHP760snk=; b=Qp5JKFdwGYj8Gar70vooSb2H3bWE0kAS4UYpnePxXIykfKcymrLtiBPn/7Ux5zAKL6MUkD ZQbx+twkue0/4TpKQl+UbCjWIAhbGkX6L7mJez7jwUQ3ySD+cHYwwnoXfiD8AE1LOuOXQF Zd7zp0mc3Mly/9duv2GsTMfspRsupIUj6nD0hh1E8R6zFyKO7xT4YuwGVAu0nTbjIhkNX+ wIh40zOoBSCvn/PcE2sAQ6dtDR+0Ykq37clezF892Ak+iW4Wx0FJQbG6s7HPqFy0oFLvA3 KIZt83R8J7V2qEt62wEKmWbS5H+O557uF9Vpg08ivGGLStoz+ej7h+LWGyviYA== MIME-Version: 1.0 Date: Wed, 11 May 2022 12:03:13 +0200 From: Wolfgang Walter To: stable@vger.kernel.org, Trond Myklebust , Chuck Lever , linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: 5.4.188 and later: massive performance regression with nfsd Message-ID: X-Sender: linux@stwm.de Organization: =?UTF-8?Q?Studentenwerk_M=C3=BCnchen?= Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Regards, -- Wolfgang Walter Studentenwerk München Anstalt des öffentlichen Rechts