Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751212AbdFBS1x (ORCPT ); Fri, 2 Jun 2017 14:27:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:49756 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750971AbdFBS1w (ORCPT ); Fri, 2 Jun 2017 14:27:52 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 11CB523A20 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=acme@kernel.org Date: Fri, 2 Jun 2017 15:27:48 -0300 From: Arnaldo Carvalho de Melo To: "Liang, Kan" Cc: Jiri Olsa , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, Stephane Eranian , Jiri Olsa , elliott@hpe.com, Andi Kleen Subject: Re: [PATCH V2 0/2] measure SMI cost (user) Message-ID: <20170602182748.GA31764@kernel.org> References: <1495825538-5230-1-git-send-email-kan.liang@intel.com> <20170529124637.GA1957@krava> <20170529125239.sxd7dp4gyjjtws5z@hirez.programming.kicks-ass.net> <20170529131642.GA3570@krava> <37D7C6CF3E00A74B8858931C1DB2F0775370293D@SHSMSX103.ccr.corp.intel.com> <37D7C6CF3E00A74B8858931C1DB2F077537053C9@SHSMSX103.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <37D7C6CF3E00A74B8858931C1DB2F077537053C9@SHSMSX103.ccr.corp.intel.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.8.0 (2017-02-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2650 Lines: 59 Em Fri, Jun 02, 2017 at 03:45:11PM +0000, Liang, Kan escreveu: > > > On Mon, May 29, 2017 at 02:52:39PM +0200, Peter Zijlstra wrote: > > > > On Mon, May 29, 2017 at 02:46:37PM +0200, Jiri Olsa wrote: > > > > > for some reason I can't get single SMI count generated, is there a > > > > > setup/bench that would provoke that? > > > > Not having SMIs is a good thing ;-) > > > > Not sure we can tickle them in a reliable way. > > > yea I saw some counts last time, now just zero so I was wondering > > > if it's working > > We have internal test case which can generate SMI, but I cannot publish the > > test case. Sorry about that. > APM_CNT (0xB2) could be used to trigger SMI#. Here if I run the following 'perf stat' command and press the mute button (the one sharing F1 in a thinkpad t450s it triggers SMIs, toggle it in quick sucession and it generates more, etc: [root@jouet ~]# perf stat -I 1000 -e msr/smi/ # time counts unit events 1.000103173 0 msr/smi/ 2.000278816 4 msr/smi/ 3.000472630 4 msr/smi/ 4.000743916 0 msr/smi/ 5.001369358 4 msr/smi/ 6.001668033 0 msr/smi/ 7.001852603 4 msr/smi/ 8.002108269 12 msr/smi/ 9.002367312 0 msr/smi/ ^C 9.961897866 0 msr/smi/ [root@jouet ~]# - Arnaldo > It's documented in PCH datasheet. > https://www.intel.com/content/dam/www/public/us/en/ > documents/datasheets/9-series-chipset-pch-datasheet.pdf > > APM_CNT-Advanced Power Management Control Port Register > I/O Address: B2h > Attribute: R/W > Default Value: 00h > Size: 8 bits > Lockable: No > Usage: Legacy Only > Power Well: Core > Bit Description > 7:0 Used to pass an APM command between the OS and the SMI handler. > Writes to this port not only store data in the APMC register, > but also generates an SMI# when the APMC_EN bit is set. > > You can write a byte to port 0xB2 to trigger an SMI# > > Thanks, > Kan