From owner-freebsd-current@freebsd.org Tue Mar 13 15:13:38 2018 Return-Path: Delivered-To: freebsd-current@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 7FE24F54F57 for ; Tue, 13 Mar 2018 15:13:38 +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 17DEE826DD; Tue, 13 Mar 2018 15:13:37 +0000 (UTC) (envelope-from slw@zxy.spb.ru) Received: from slw by zxy.spb.ru with local (Exim 4.86 (FreeBSD)) (envelope-from ) id 1evlcG-000Gtr-2d; Tue, 13 Mar 2018 18:13:28 +0300 Date: Tue, 13 Mar 2018 18:13:28 +0300 From: Slawa Olhovchenkov To: Arshan Khanifar Cc: Ed Maste , FreeBSD Current Subject: Re: Performance Benchmark for PTI (aka Meltdown mitigation) Message-ID: <20180313151327.GQ81872@zxy.spb.ru> References: <20180309120131.GA38546@zxy.spb.ru> <20180309151606.GP81872@zxy.spb.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: slw@zxy.spb.ru X-SA-Exim-Scanned: No (on zxy.spb.ru); SAEximRunCond expanded to false X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 13 Mar 2018 15:13:38 -0000 On Mon, Mar 12, 2018 at 04:36:05PM -0400, Arshan Khanifar wrote: > I did some benchmarking for the two revisions: > results are here: > https://github.com/ArshanKhanifar/pti-benchmark/tree/master/stable-11-pre-after/results > first file is before pti patch and second file is after pti patch. 10x! .2 is is before pti patch and .4 is after pti patch? This is like pti patch (w/ pti off) do small speed up (about 1%)? > On Fri, Mar 9, 2018 at 10:16 AM, Slawa Olhovchenkov wrote: > > > On Fri, Mar 09, 2018 at 09:58:55AM -0500, Ed Maste wrote: > > > > > On 9 March 2018 at 07:01, Slawa Olhovchenkov wrote: > > > > On Thu, Mar 08, 2018 at 05:04:11PM -0500, Arshan Khanifar wrote: > > > > > > > >> Executive Summary: > > > >> - The PTI feature increases the system call times by more than 100%. > > > >> - As a macrobenchmark, buildworld was used. Wall clock and user time > > > >> showed no statistically-significant changes, while system time > > > >> increased by less than 5%. > > > >> > > > >> This email contains the results for benchmarking the performance of > > the > > > >> PTI patch on FreeBSD 12-current. As a microbenchmark, timing of > > > >> getppid(2) system call was used, and as a macrobenchmark, a number of > > > >> buildworld tasks were timed. > > > >> > > > > > > > > Can you also run pre-patched kernel? > > > > > > It's not easy to do an apples-to-apples comparison as there were a few > > > followup changes to the PTI work, interspersed with unrelated changes. > > > That said, I think Arshan has some benchmarks obtained during the > > > development of the PTI changes that may be illustrative. > > > > > > The best approach is probably to compare stable/11 at r329450 (last > > > stable/11 revision before the merge) with r329462 with PTI and IBRS > > > disabled. > > > > Stable/11 more interesting to me, nice to see. > > > >