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=-5.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 154DAC2BB55 for ; Wed, 15 Apr 2020 15:01:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C19420857 for ; Wed, 15 Apr 2020 15:01:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="unknown key version" (0-bit key) header.d=tlapnet.cz header.i=@tlapnet.cz header.b="Khe1JGR6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733223AbgDOPBU (ORCPT ); Wed, 15 Apr 2020 11:01:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1729634AbgDOPBO (ORCPT ); Wed, 15 Apr 2020 11:01:14 -0400 Received: from mail-qv1-xf42.google.com (mail-qv1-xf42.google.com [IPv6:2607:f8b0:4864:20::f42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 140FAC061A0C for ; Wed, 15 Apr 2020 08:01:14 -0700 (PDT) Received: by mail-qv1-xf42.google.com with SMTP id v38so164191qvf.6 for ; Wed, 15 Apr 2020 08:01:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tlapnet.cz; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=mNIp0Kdot9FDRrFvUr4+w9a30uBv7DsgDCQSVOvqmEk=; b=Khe1JGR6/j2TJI37r4ihSPj0CSOtlouACt5LJxoDdbCiE/am43qGFvxFnJce+Vkv4j kyb0yBAzWWYvUcaL6WkLXmNV1qJLhT6B2tKqqsT9vvCQv3Ve8dz8Z7vm1av1LcEdP0fu D9VhUQEEiI4qjq6iKxKguuhgvP4iwGmkRT7fYzKnoiH/0JXv4L6FXfby3eVe6SBs06hW O9FFL7+afCr05YMLgENwIu8K+y6GZRVvX/YyR7xudqyf0j9bj2lYccA11IjmtMxtH9vO EeG9CHzeDNTcmgUQfp62i9syDapK5grdeKR3s7DP+XtSNQimlhlunVLQWW1tynFFpw3X KrEw== 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:cc:content-transfer-encoding; bh=mNIp0Kdot9FDRrFvUr4+w9a30uBv7DsgDCQSVOvqmEk=; b=Cy+5NabkJUlixSRnS0inOn/MzVBWvAF01eutEmASWlKOEfsgOLmK/n5M2K4YF/Q5tK wwI9hGBpYuw9VRi6UldTJGv7zMVCeLLLtmOIFdkMK3G++dCpBPed1Q6F+eMPXnrRwVrI uiRydKjREoVSvu95H0qQrJkVuorWSKej56rB1RLKdXnAXJZXxYx6fWY+3bbJdslHW/H3 a3Zg4WTugbh1rhU9Vy3LClS7udyRmzwrGEqRH5nnwoiNk4a/i5aLSHGigD8OmA/+Gtfv WuWwiP+p/6kEYnfCNqxogtlZsyj8Pe8YLdrM98w4f31O41TU42+wVKlV/dAOOXCPoesB f3DA== X-Gm-Message-State: AGi0PuYKa/wtUURc7EV0DdLpCwWK2NcNEE7+C/KG1G+r+soL9WT87HE+ 92wcsl2P8Mmh5V20pVVZWB922xs2V7hjQ1Xtp73+kw== X-Google-Smtp-Source: APiQypKETDduT8D+7vnJ8GMxPaK6Hkwmy5etn1YQmS2ARVrw8rEOZpM3kJnUO30srYWQJFLdo5eUiYREXdJsx7ZxTvE= X-Received: by 2002:a0c:c305:: with SMTP id f5mr5372473qvi.220.1586962873121; Wed, 15 Apr 2020 08:01:13 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: =?UTF-8?Q?V=C3=A1clav_Zindulka?= Date: Wed, 15 Apr 2020 17:01:01 +0200 Message-ID: Subject: Re: iproute2: tc deletion freezes whole server To: Cong Wang Cc: Linux Kernel Network Developers Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Apr 13, 2020 at 7:29 PM Cong Wang wrote: > > On Sun, Apr 12, 2020 at 1:18 PM V=C3=A1clav Zindulka > wrote: > > > > On Wed, Apr 8, 2020 at 10:18 PM Cong Wang wr= ote: > > > > > > Hi, V=C3=A1clav > > > > Hello Cong, > > > > > Sorry for the delay. > > > > No problem, I'm actually glad you are diagnosing the problem further. > > I didn't have much time until today and late yesterday to apply > > patches and to test it. > > > > > The problem is actually more complicated than I thought, although it > > > needs more work, below is the first pile of patches I have for you to > > > test: > > > > > > https://github.com/congwang/linux/commits/qdisc_reset > > > > > > It is based on the latest net-next branch. Please let me know the res= ult. > > > > I have applied all the patches in your four commits to my custom 5.4.6 > > kernel source. There was no change in the amount of fq_codel_reset > > calls. Tested on ifb, RJ45 and SFP+ interfaces. > > It is true my patches do not reduce the number of fq_codel_reset() calls, > they are intended to reduce the CPU time spent in each fq_codel_reset(). > > Can you measure this? Note, you do not have to add your own printk() > any more, because my patches add a few tracepoints, especially for > qdisc_reset(). So you can obtain the time by checking the timestamps > of these trace events. Of course, you can also use perf trace like you > did before. Sorry for delayed responses. We were moving to a new house so I didn't have much time to test it. I've measured your pile of patches applied vs unpatched kernel. Result is a little bit better, but it is only about 1s faster. Results are here. Do you need any additional reports or measurements of other interfaces? https://github.com/zvalcav/tc-kernel/tree/master/20200415 I've recompiled the kernel without printk which had some overhead too.