From owner-svn-src-all@freebsd.org  Sat Aug 27 00:46:22 2016
Return-Path: <owner-svn-src-all@freebsd.org>
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 3E5D3A94244;
 Sat, 27 Aug 2016 00:46:22 +0000 (UTC) (envelope-from slw@zxy.spb.ru)
Received: from zxy.spb.ru (zxy.spb.ru [195.70.199.98])
 (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 F2C8692D;
 Sat, 27 Aug 2016 00:46:21 +0000 (UTC) (envelope-from slw@zxy.spb.ru)
Received: from slw by zxy.spb.ru with local (Exim 4.86 (FreeBSD))
 (envelope-from <slw@zxy.spb.ru>)
 id 1bdRlJ-000KxR-Sc; Sat, 27 Aug 2016 03:46:17 +0300
Date: Sat, 27 Aug 2016 03:46:17 +0300
From: Slawa Olhovchenkov <slw@zxy.spb.ru>
To: Adrian Chadd <adrian@freebsd.org>
Cc: Bruce Simpson <bms@fastmail.net>, Ryan Stone <rysto32@gmail.com>,
 "svn-src-head@freebsd.org" <svn-src-head@freebsd.org>,
 Ryan Stone <rstone@freebsd.org>,
 "src-committers@freebsd.org" <src-committers@freebsd.org>,
 "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>
Subject: Re: svn commit: r304436 - in head: . sys/netinet
Message-ID: <20160827004617.GJ88122@zxy.spb.ru>
References: <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>
 <CAJ-Vmomg6ejJdZessaUU3DF+V+sQd=hMZwo_pDYpa4XjoB_ZcA@mail.gmail.com>
 <20160826213613.GH88122@zxy.spb.ru>
 <CAJ-VmomRDdg5EUUiAHOyVBzitd8cZ8bPGCrU9btnveWeW-_85g@mail.gmail.com>
 <20160826220255.GI88122@zxy.spb.ru>
 <CAJ-VmomFuh07_vBi+zdNrPs3+Dni1AtYh_VNKbnACydbCxr7gw@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAJ-VmomFuh07_vBi+zdNrPs3+Dni1AtYh_VNKbnACydbCxr7gw@mail.gmail.com>
User-Agent: Mutt/1.5.24 (2015-08-30)
X-SA-Exim-Connect-IP: <locally generated>
X-SA-Exim-Mail-From: slw@zxy.spb.ru
X-SA-Exim-Scanned: No (on zxy.spb.ru); SAEximRunCond expanded to false
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 \(except for &quot;
 user&quot; and &quot; projects&quot; \)" <svn-src-all.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-all/>
List-Post: <mailto:svn-src-all@freebsd.org>
List-Help: <mailto:svn-src-all-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 27 Aug 2016 00:46:22 -0000

On Fri, Aug 26, 2016 at 04:55:34PM -0700, Adrian Chadd wrote:

> Hi,
> 
> I use the kernel lock profiling debugging,

I am already have 100% utilise all CPU cores, I think this is drop
performance?

> but you can use dtrace to
> get an idea:
> 
> dtrace -n 'lockstat:::adaptive-block { @[stack()] = sum(arg1); }'

How to interpret results (how to distinct lock contention from lock
cost/overhead (LOCK CMPXCGQ is very expensive))?

> (https://wiki.freebsd.org/DTrace/One-Liners)
> 
> 
> 
> -adrian