From owner-svn-src-head@freebsd.org Fri Aug 26 15:08:00 2016 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id E8216B7044B; Fri, 26 Aug 2016 15:08:00 +0000 (UTC) (envelope-from bms@fastmail.net) Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com [66.111.4.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id A9D441E4; Fri, 26 Aug 2016 15:08:00 +0000 (UTC) (envelope-from bms@fastmail.net) Received: from compute2.internal (compute2.nyi.internal [10.202.2.42]) by mailout.nyi.internal (Postfix) with ESMTP id E598020658; Fri, 26 Aug 2016 11:01:24 -0400 (EDT) Received: from frontend1 ([10.202.2.160]) by compute2.internal (MEProxy); Fri, 26 Aug 2016 11:01:26 -0400 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=fastmail.net; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-sasl-enc :x-sasl-enc; s=mesmtp; bh=EScbBIOR5Q4O+jvbs5waVB75F1o=; b=mVBKIx K601n+EBfCdigX9vRfSb859AtfBpllOKPEzNf2WdK7JbaErVa2gwHUKWsagz9IP7 jnrJb1LiwGhh0rKgImvSEXmY4ZMr72fnsZPjYpJm+5A8st/dfT1XFR3YobKIgOR3 xDl7KwfyhcJYe8TBgdg2ZNh3nQU4gBDyoBrug= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-sasl-enc:x-sasl-enc; s=smtpout; bh=EScbBIOR5Q4O+jv bs5waVB75F1o=; b=nkW05rvEX1aoGdfLG7xbfgyeExHPi1ojsJy12UI2UNxaE+K dWo9QNvPHaZ3bWtThIRi6f2e0Z/v6XuKYvLJpU7kOrCSmxdcILZoZvrIuSxGvdYn JonWnG4vQoem5NmbYnX4/FqpgRKBY4ETedcCcCJ+NsSbdUsalanIwMb9Zl1w= X-Sasl-enc: Ow/aoGNKGWugFkLtbC2N4V+kudrAeF9z0gpjaPJ9ORz0 1472223684 Received: from pion.local (cpc96954-walt26-2-0-cust843.13-2.cable.virginm.net [82.31.91.76]) by mail.messagingengine.com (Postfix) with ESMTPA id BE0A2F29D0; Fri, 26 Aug 2016 11:01:23 -0400 (EDT) Subject: Re: svn commit: r304436 - in head: . sys/netinet To: Slawa Olhovchenkov References: <20160820184506.GV8192@zxy.spb.ru> <0f42c5fb-f930-c6e3-75d6-df97f67c201d@fastmail.net> <20160820204106.GW8192@zxy.spb.ru> <0acba141-4701-d9c2-0ddb-46d1f60ff55b@fastmail.net> <20160820220510.GX8192@zxy.spb.ru> <8ac23bd1-dcb3-7c64-f195-5039f9af0eaf@fastmail.net> <20160821000400.GY8192@zxy.spb.ru> <20160826144926.GE88122@zxy.spb.ru> Cc: Ryan Stone , "svn-src-head@freebsd.org" , Ryan Stone , "src-committers@freebsd.org" , "svn-src-all@freebsd.org" , Adrian Chadd From: Bruce Simpson Message-ID: <3dba1b70-54cc-0bb1-5cc8-8c56cd750bec@fastmail.net> Date: Fri, 26 Aug 2016 16:01:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <20160826144926.GE88122@zxy.spb.ru> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Aug 2016 15:08:01 -0000 Slawa, I'm afraid this may be a bit of a non-sequitur. Sorry.. I seem to be missing something. As I understand it this thread is about Ryan's change to netinet for broadcast. On 26/08/16 15:49, Slawa Olhovchenkov wrote: > On Sun, Aug 21, 2016 at 03:04:00AM +0300, Slawa Olhovchenkov wrote: >> On Sun, Aug 21, 2016 at 12:25:46AM +0100, Bruce Simpson wrote: >>> Whilst I agree with your concerns about multipoint, I support the >>> motivation behind Ryan's original change: optimize the common case. >> >> Oh, common case... >> I am have pmc profiling for TCP output and see on this SVG picture and >> don't find any simple way. >> You want to watch too? > > At time peak network traffic (more then 25K connections, about 20Gbit > total traffic) half of cores fully utilised by network stack. > > This is flamegraph from one core: http://zxy.spb.ru/cpu10.svg > This is same, but stack cut of at ixgbe_rxeof for more unified > tcp/ip stack view http://zxy.spb.ru/cpu10u.svg ... I appreciate that you've taken the time to post a flamegraph (a fashionable visualization) of relative performance in the FreeBSD networking stack. Sadly, I am mostly out of my depth for looking at stack wide performance for the moment; for the things I look at involving FreeBSD at work just at the moment, I would not generally go down there except for specific performance issues (e.g. with IEEE 1588). It sounds as though perhaps you should raise a wider discussion about your results on -net. I would caution you however that the Function Boundary Trace (FBT) provider for DTrace can introduce a fair amount of noise to the raw performance data because of the trap mechanism it uses. This ruled it out for one of my own studies requiring packet-level accuracy. Whilst raw pmc(4) profiles may require more post-processing, they will provide less equivocal data (and a better fix) on the hot path, due also to being sampled effectively on a PMC interrupt (a gather stage- poll core+uncore MSRs), not purely a software timer interrupt. thanks Bruce