From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Neugebauer Subject: RE: Haswell EP some uncore imc counter are missing Date: Wed, 28 Sep 2016 00:20:08 +0200 Message-ID: <1475014808.6854.0@smtp.gmail.com> References: <20160917180155.Horde.5aCQxGa9_V0-tbqDKZDTDx2@horde.inf.h-brs.de> <37D7C6CF3E00A74B8858931C1DB2F07750C6289A@SHSMSX103.ccr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Return-path: Received: from mail-wm0-f44.google.com ([74.125.82.44]:35805 "EHLO mail-wm0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752151AbcI0WUN (ORCPT ); Tue, 27 Sep 2016 18:20:13 -0400 Received: by mail-wm0-f44.google.com with SMTP id l132so202328837wmf.0 for ; Tue, 27 Sep 2016 15:20:11 -0700 (PDT) In-Reply-To: <37D7C6CF3E00A74B8858931C1DB2F07750C6289A@SHSMSX103.ccr.corp.intel.com> Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: "Liang, Kan" Cc: Michael Petlan , Christian Neugebauer , "linux-perf-users@vger.kernel.org" Sorry for my late reply, I was gone. @Kan: perfect, thanks a lot for the clarification! That was actually the point where I got confused, because I saw that there were 8 imc counter registered in the source code for Haswell-EP. Now, I don't have to worry to miss any information regarding the imc counter. @Michael: thank you for your reply as well! On Mi, Sep 21, 2016 at 10:16 , Liang, Kan wrote: > > Haswell EP can only support at most 4 channels for each processor. > That's correct that you only observe 4 IMCs. > > However, there are 8 possible device location for IMC channels on > Haswell. > Where are those channels located depends on the memory configuration, > which is different among machines. > > In uncore driver, we have all 8 possible device coded. It's from > imc_0 to imc_7. > But there will be only 4 IMCs observed at runtime. The unused ones > are hidden. > > Thanks, > Kan > > >> On Sat, 17 Sep 2016, Christian Neugebauer wrote: >> > >> > Hi, >> > >> > We encountered the following problem with perf. We want to >> measure the >> > total memory bandwidth by using the uncore imc counter >> uncore_imc_0, >> > uncore_imc_1, ..., uncore_imc_7. In our system the counter >> > uncore_imc_2, uncore_imc_3, uncore_imc_6, uncore_imc_7 are NOT >> listed >> > under /sys/devices. Only uncore_imc_0, uncore_imc_1, uncore_imc_4, >> > uncore_imc_5 are available (linked under /sys/device and >> accessible via >> perf). >> > >> >> Hi, >> >> When I tested uncore with perf on (probably) the same (or very >> similar) >> Haswell EP CPU as the one of yours, I also have seen only imcs 0, >> 1, 4, 5. Are >> you sure the 2, 3, 6, 7 should really be there (are supported by >> the CPU itself)? >> >> My guess would be that the 2, 3, 6, 7 slots are reserved/unused. >> >> Could you attach more info about your CPU topology (cpuid, lstopo, >> ...)? >> >> This was the CPU I used: >> >> Intel(R) Xeon(R) CPU E5-2697 v3 @ 2.60GHz >> Family: 6 >> Model: 63 >> Stepping: 2 >> RAM: 31976 MB >> 56 processors on 28 cores organized into 2 numa nodes >> >> Unfortunatelly, I didn't stored my topology logs, however I think >> it is as I said >> above. >> >> Cheers, >> Michael >> >> >> > Our setup: >> > >> > - 2 x Intel Xeon E5-2697 v3 (Haswell EP) >> > - uname -a >> > Linux wr5 2.6.32-642.4.2.el6.x86_64 #1 SMP Tue Aug 23 11:15:56 CDT >> > 2016 >> > x86_64 x86_64 x86_64 GNU/Linux >> > - perf --version >> > perf version 2.6.32-642.4.2.el6.x86_64.debug >> > >> > From my understanding 8 imc counter in total should be available >> for >> > Haswell EP. The kernel is a fresh build which seems to have all >> latest >> > perf changes in it. I also checked the perf source code briefly. I >> > could do more debugging and try to find out the problem but before >> > that I want to know if this is either a known problem, an unknown >> > problem or no problem at all because there are restrictions that >> I'm not >> aware of. >> > >> > I also double checked other machines (same kernel though). E.g >> Intel >> > Xeon >> > E5-2697 v2 (Ivy Bridge EP) shows me 8 counters as expected, and >> if I >> > remember correctly Intel Xeon EP E5-2670 (Sandy Bridge EP) had 4 >> > counter, could double check that if necessary. >> > >> > Chris >> > -- >> > Christian Neugebauer >> > >> > -- >> > To unsubscribe from this list: send the line "unsubscribe >> linux-perf-users" >> > in >> > the body of a message to majordomo@vger.kernel.org More majordomo >> info >> > at http://vger.kernel.org/majordomo-info.html >> > >> -- >> To unsubscribe from this list: send the line "unsubscribe >> linux-perf-users" in >> the body of a message to majordomo@vger.kernel.org More majordomo >> info at http://vger.kernel.org/majordomo-info.html >