From owner-svn-src-all@freebsd.org Fri Aug 26 21:32:02 2016 Return-Path: Delivered-To: svn-src-all@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 91378B767CA; Fri, 26 Aug 2016 21:32:02 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-it0-x22b.google.com (mail-it0-x22b.google.com [IPv6:2607:f8b0:4001:c0b::22b]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 568F817B; Fri, 26 Aug 2016 21:32:02 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: by mail-it0-x22b.google.com with SMTP id x131so13865435ite.0; Fri, 26 Aug 2016 14:32:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=wJeldIF8xsXC1rpixm5hNF7vdLJLc3cCqQ8wCeyIdjU=; b=V7nbByHgApSSY7xh8KAXPZSCrDORg/CpstGeCxmgAoJkbfhzGAFNPZ5UU+00vlfeVG lssWilYowg/YrwrvKnvQNlaxM42iPtejPBngnME3MuTvYLAPDJvpMGbkXz3mp7ZLyU1a 30SALThoXfJk18D696GfgnrUh1OHOtxCZ6rq5n3fO88b4ArI6PBH3QKJ4/m8Ssm/nKw8 BXOF/0XN35qUYe8+SJBIKr2Wgwkj/9FCdeIJSwZ47s0eAzfdKpg6NpMXL7VBidAzNP3R CExQ9izCrx7+m9zHtgCt15HgANTLodJgj5HrgGaccFujZsjXgXqNZLXqeGxRsV1vbFAA 99dg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=wJeldIF8xsXC1rpixm5hNF7vdLJLc3cCqQ8wCeyIdjU=; b=VmDmQufBrxiz4LYYVbfXcWhxJrp+Mte6gWuK3RJwHREDsZiV6x34lkwls/Y6ufe5GM ciWx2q3nS+Qht9YM9AAipESTRw7AlXgs6fkJdn4KqZNTPUamOK0V5Y7lYSXzYoOK3ONc 6hJLsyjoOxoTOlVDImeSnhecL+ThBionXCqJOsxCs3sglg2A70t8Lxbz8h1yj2T6s8D0 /GEqv2LK9FHnaAsmo+km1i0h3YJDA7TPfbO8GnJ7qMz4QItI57tbWEe4nIxTolEISBzp lvb3XdGacbE7GhHHtmrqETqzR0gua5Q99EsYtHXgBf8Hwmtv5gWAkfpaB96Xjkw7PvIO 1R3g== X-Gm-Message-State: AE9vXwPc9DaajLN/sQpSaKJwoJ71Ns9zLrPL6qlyB5kh2CGHO0pFJZIwZBOdAZ6D1aNypzvqoYuLdQk3EA1HZg== X-Received: by 10.36.212.6 with SMTP id x6mr1087732itg.71.1472247121770; Fri, 26 Aug 2016 14:32:01 -0700 (PDT) MIME-Version: 1.0 Sender: adrian.chadd@gmail.com Received: by 10.36.141.129 with HTTP; Fri, 26 Aug 2016 14:32:00 -0700 (PDT) In-Reply-To: <20160826151324.GF88122@zxy.spb.ru> References: <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> <3dba1b70-54cc-0bb1-5cc8-8c56cd750bec@fastmail.net> <20160826151324.GF88122@zxy.spb.ru> From: Adrian Chadd Date: Fri, 26 Aug 2016 14:32:00 -0700 X-Google-Sender-Auth: w5OTdB4XYgVIJjEbbPh2Lf3SwBg Message-ID: Subject: Re: svn commit: r304436 - in head: . sys/netinet To: Slawa Olhovchenkov Cc: Bruce Simpson , Ryan Stone , "svn-src-head@freebsd.org" , Ryan Stone , "src-committers@freebsd.org" , "svn-src-all@freebsd.org" Content-Type: text/plain; charset=UTF-8 X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Aug 2016 21:32:02 -0000 Hi, It's pcb lock contention. -adrian On 26 August 2016 at 08:13, Slawa Olhovchenkov wrote: > On Fri, Aug 26, 2016 at 04:01:14PM +0100, Bruce Simpson wrote: > >> 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 for answer, I am now try to start discussion on -net.