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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 313F9C2D0C0 for ; Thu, 26 Dec 2019 23:36:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 01F722080D for ; Thu, 26 Dec 2019 23:36:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726897AbfLZXgA (ORCPT ); Thu, 26 Dec 2019 18:36:00 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:44658 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725909AbfLZXgA (ORCPT ); Thu, 26 Dec 2019 18:36:00 -0500 Received: from localhost (unknown [IPv6:2601:601:9f00:1c3::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 4E467153A868B; Thu, 26 Dec 2019 15:35:59 -0800 (PST) Date: Thu, 26 Dec 2019 15:35:58 -0800 (PST) Message-Id: <20191226.153558.876242092356247020.davem@davemloft.net> To: edumazet@google.com Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, soheil@google.com, ncardwell@google.com Subject: Re: [PATCH net] net_sched: sch_fq: properly set sk->sk_pacing_status From: David Miller In-Reply-To: <20191223191324.49554-1-edumazet@google.com> References: <20191223191324.49554-1-edumazet@google.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Thu, 26 Dec 2019 15:35:59 -0800 (PST) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Eric Dumazet Date: Mon, 23 Dec 2019 11:13:24 -0800 > If fq_classify() recycles a struct fq_flow because > a socket structure has been reallocated, we do not > set sk->sk_pacing_status immediately, but later if the > flow becomes detached. > > This means that any flow requiring pacing (BBR, or SO_MAX_PACING_RATE) > might fallback to TCP internal pacing, which requires a per-socket > high resolution timer, and therefore more cpu cycles. > > Fixes: 218af599fa63 ("tcp: internal implementation for pacing") > Signed-off-by: Eric Dumazet Applied and queued up for -stable, thanks Eric.