From mboxrd@z Thu Jan 1 00:00:00 1970 From: Manuel Selva Subject: Re: About using PEBS from the user space Date: Thu, 25 Jun 2015 21:06:17 +0200 Message-ID: <558C5129.70207@gmail.com> References: <55469B90.1090903@bsc.es> <558C25AE.9040601@bsc.es> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wi0-f169.google.com ([209.85.212.169]:34329 "EHLO mail-wi0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751535AbbFYTGV (ORCPT ); Thu, 25 Jun 2015 15:06:21 -0400 Received: by wicnd19 with SMTP id nd19so26517191wic.1 for ; Thu, 25 Jun 2015 12:06:20 -0700 (PDT) In-Reply-To: <558C25AE.9040601@bsc.es> Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: Harald Servat , Vince Weaver Cc: "linux-perf-users@vger.kernel.org" Hello Harald, Setting the config1 field of the perf_event_attr field (as done by the perf mem record tool) to X will instruct the PMU to only sample loads with latency higher than X. Is it what you are looking for ? ---- Manu On 06/25/2015 06:00 PM, Harald Servat wrote: > On 04/05/15 00:19, Vince Weaver wrote: >> On Mon, 4 May 2015, Harald Servat wrote: >> >>> Dear list, >>> >>> I'd like to use the perf library to access PEBS so as to collect >>> referenced >>> memory addresses from the user space. I think I've successfully setup >>> the perf >>> structures (struct perf_event_attr) to configure the performance >>> counters, but >>> I don't see what should I do to access to the captured memory >>> addresses. I've >>> seen that within arch/x86/kernel/cpu/perf_event_intel_ds.c there are the >>> routines alloc_pebs_buffer, alloc_ds_buffer which seems to allocate >>> and setup >>> the necessary buffers using kmalloc_node calls. Question is, how can >>> replicate >>> this from the user space? And how we should connect these buffers to >>> the PEBS >>> infrastructure using perf calls? >> >> You can try looking at the example code in my perf_event_tests code. >> https://github.com/deater/perf_event_tests >> >> The stuff you are looking for is probably covered in the >> test/record_sample/samples_data_src >> test/record_sample/sample_weight >> and especially the >> test/record_sample/sample_regs_intr >> tests, although that last one requires a fairly recent kernel to work. >> >> Vince > > Hello, > > is there a way to setup PEBS to collect information from loads that > take at least X cycles to complete using MSR_PEBS_LD_LAT_THRESHOLD > through this approach? > > Thank you! > > WARNING / LEGAL TEXT: This message is intended only for the use of the > individual or entity to which it is addressed and may contain > information which is privileged, confidential, proprietary, or exempt > from disclosure under applicable law. If you are not the intended > recipient or the person responsible for delivering the message to the > intended recipient, you are strictly prohibited from disclosing, > distributing, copying, or in any way using this message. If you have > received this communication in error, please notify the sender and > destroy and delete any copies you may have received. > > http://www.bsc.es/disclaimer > -- > 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 > >