From owner-svn-src-all@freebsd.org Sun Jul 26 20:32:53 2015 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 D34879ABB30 for ; Sun, 26 Jul 2015 20:32:53 +0000 (UTC) (envelope-from scott4long@yahoo.com) Received: from nm8-vm8.bullet.mail.gq1.yahoo.com (nm8-vm8.bullet.mail.gq1.yahoo.com [98.136.218.231]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id A3604EC4 for ; Sun, 26 Jul 2015 20:32:53 +0000 (UTC) (envelope-from scott4long@yahoo.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1437942448; bh=o0NaeW+7oMfRCSx+/IjLDi4J6CD3H2J1ULOyIr4pc7k=; h=Subject:From:In-Reply-To:Date:Cc:References:To:From:Subject; b=uXwLnH7YkrhceELrM7U1WDjMy972kR66pas/7A8O+4zYxHljGGcaVM7uhnsnxfySqsECT3qA3aKeQIEGLrHtNCf6dcsgnTYUbsPC3lF5an/oKrXAtEp/sFLE7+sPbHuryKPkRQTRSxHu7aG/pzmRUfRMrGpMGhXN/pN0IGzUMxLkf8Le9CrPu9r1sQfiIYJ/U1aP+KRoon67YkYcgdeRxVD595HxDgk+tySLN7irkroqbeXlTePHW4IHDvtTZrb9/QXD0NQV6dOp9xg44CwIHoQLFExHHObJu5NbWO4HqmEfwC2Z30xMMtUSo9HuV7UMy5PQiRMjmW5tS0qfiHKEkQ== Received: from [98.137.12.56] by nm8.bullet.mail.gq1.yahoo.com with NNFMP; 26 Jul 2015 20:27:28 -0000 Received: from [98.136.164.70] by tm1.bullet.mail.gq1.yahoo.com with NNFMP; 26 Jul 2015 20:27:28 -0000 Received: from [127.0.0.1] by smtp232.mail.gq1.yahoo.com with NNFMP; 26 Jul 2015 20:27:28 -0000 X-Yahoo-Newman-Id: 199026.83405.bm@smtp232.mail.gq1.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: hns4q8UVM1myh0oaaA3p.GrECySS5IGGa51tlA8F.BNYNW. 5cQqYX4TwqgbXyWaR4.doKDESKMODGn.SPx5V7tQuweIyHeFWNOpCu1XB4RI 5hVt2m0rNgj3gy8QbKz9UZibfSPW.bRfqeleFkZe8RAPpdhGvGDd02IE92qO mBVJsyg1hFARRkR6AxQxGf4SzdUChbR9hotfMjIErbCrj9sMS40bj8ljMAvu YX5cY0TJuno3uHvHVVCl3jjajVjR7AzOsa7mDWJVruuvHAdTHSU_DuDrB2vc bUPE0veh6lJroCPDFJJjI41CC6R0F6hiNya10T1bJGr4fmukS2Yu7iEfFCEX L.OV6lNg6roA3.BLMGU9dHp1BRWD7wJLmebFnFSUA_wA315WZM9Entcd17yz sGvXF00bI7Pr_ZDR4qk3lwwRy8AW43xHRuugP4vXnf7awhLEPiM0WO0Fjitz nXMsiSfpwu_ky2c7x.Bi0iADD0tOQ9RwhzJcDfa12Bigfr7bcjiVmq7oc2Zg 1T2vAL3EJnhXqkHIDOXX34a_40aJOt.LtlDQ0YsfT X-Yahoo-SMTP: clhABp.swBB7fs.LwIJpv3jkWgo2NU8- Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2098\)) Subject: Re: svn commit: r284297 - in head: cddl/contrib/opensolaris/cmd/lockstat sys/kern sys/sys From: Scott Long In-Reply-To: <201506121001.t5CA1PTm089721@svn.freebsd.org> Date: Sun, 26 Jul 2015 14:27:25 -0600 Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Content-Transfer-Encoding: 7bit Message-Id: References: <201506121001.t5CA1PTm089721@svn.freebsd.org> To: Andriy Gapon X-Mailer: Apple Mail (2.2098) X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.20 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: Sun, 26 Jul 2015 20:32:53 -0000 > On Jun 12, 2015, at 4:01 AM, Andriy Gapon wrote: > > Author: avg > Date: Fri Jun 12 10:01:24 2015 > New Revision: 284297 > URL: https://svnweb.freebsd.org/changeset/base/284297 > > Log: > several lockstat improvements > > 0. For spin events report time spent spinning, not a loop count. > While loop count is much easier and cheaper to obtain it is hard > to reason about the reported numbers, espcially for adaptive locks > where both spinning and sleeping can happen. > So, it's better to compare apples and apples. > This causes spinning to be exceptionally more expensive just by having KDTRACE_HOOKS enabled, whether or not Dtrace is actually in use. It makes it undesirable to deploy with Dtrace by default since it impacts performance. Is there a way to make the expensive collection optional, or only enable when dtrace is using the lockstat module? Also have you seen the other recent performance complaint related to this commit? Thanks, Scott