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 2F0E7C433EF for ; Mon, 13 Jun 2022 09:11:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229811AbiFMJLZ (ORCPT ); Mon, 13 Jun 2022 05:11:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44734 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230369AbiFMJLY (ORCPT ); Mon, 13 Jun 2022 05:11:24 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED963F5B4 for ; Mon, 13 Jun 2022 02:11:23 -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 A0706B80E42 for ; Mon, 13 Jun 2022 09:11:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F9D6C34114; Mon, 13 Jun 2022 09:11:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655111481; bh=mZzbMQlKS9GDr/ck9JoDE9FL0bFbykpWNMphJ6P7ATg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=gljt8AfLH9UMlCsUm62JEM8tliPOQfCsEg4iy/kn4SGfyoXJvQdByu+gvBTExU8yt ROgPdtkPX4bGLKRyaHvcCqEaGkF16/IRlHGsL6P7juKFPirU15IM6jjpW2ntLqMG5I uoK7JCbxUUpevoPdSDt2JU+3BZDt3raKwoF+IUPM= Date: Mon, 13 Jun 2022 11:11:18 +0200 From: Greg KH To: Davide Caratti Cc: stable@vger.kernel.org, echaudro@redhat.com, i.maximets@ovn.org Subject: Re: net/sched: act_police: more accurate MTU policing 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: stable@vger.kernel.org On Fri, Jun 10, 2022 at 07:08:48PM +0200, Davide Caratti wrote: > hello Greg, > > thanks for looking at this! > > On Fri, Jun 10, 2022 at 05:09:21PM +0200, Greg KH wrote: > > On Fri, Jun 10, 2022 at 04:58:37PM +0200, Davide Caratti wrote: > > > hello, > > > > > > Ilya reports bad TCP throughput when GSO packets hit an OVS rule that does > > > tc MTU policing. According to his observations [1], the problem is fixed > > > by upstream commit 4ddc844eb81d ("net/sched: act_police: more accurate MTU > > > policing"). Can we queue this commit for inclusion in stable trees? > > > > Did you test this, > > I tested it on upstream, RHEL8 and RHEL9 kernels. BTW, the kselftest I included > in the commit only verifies the correct setting for the MTU threshold, not > the GSO problem (to test GSO, we should use netperf / iperf3 rather than > mausezahn to generate traffic). > > > and what kernel(s) do you want it applied to? > > the reported bug is in act_police since the very beginning; however, the > patch should apply cleanly at least on 5.x kernels. On older ones, there > might be a small conflict due to lack of RCU-ification of struct > tcf_police_params. > A conflict that gets fixed easily, but in case we need it I volunteer to > write a patch for kernels older than 4.20. @Ilya, what is the > minimum kernel usable for openvswitch with MTU policing? > It does not apply to 5.10 or earlier, so please provide a working backport for those kernels if you wish it to be applied there. thanks, greg k-h