Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756092Ab3JGQTe (ORCPT ); Mon, 7 Oct 2013 12:19:34 -0400 Received: from mail.skyhub.de ([78.46.96.112]:59776 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753218Ab3JGQTc (ORCPT ); Mon, 7 Oct 2013 12:19:32 -0400 Date: Mon, 7 Oct 2013 18:19:29 +0200 From: Borislav Petkov To: Stephane Eranian Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@elte.hu, ak@linux.intel.com, acme@redhat.com, jolsa@redhat.com, zheng.z.yan@intel.com Subject: Re: [PATCH v1 0/2] perf,x86: add Intel RAPL PMU support Message-ID: <20131007161928.GC5517@pd.tnic> References: <1381162158-24329-1-git-send-email-eranian@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1381162158-24329-1-git-send-email-eranian@google.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1599 Lines: 39 On Mon, Oct 07, 2013 at 06:09:15PM +0200, Stephane Eranian wrote: > The counters all count in the same unit. The perf_events API > exposes all RAPL counters as 64-bit integers counting in unit > of 1/2^32 Joules (or 0.23 nJ). User level tools must convert > the counts by multiplying them by 0.23 and divide 10^9 to > obtain Joules. The reason for this is that the kernel avoids > doing floating point math whenever possible because it is > expensive (user floating-point state must be saved). The method > used avoids kernel floating-point and minimizes the loss of > precision (bits). Thanks to PeterZ for suggesting this approach. > > To convert the raw count in Watt: W = C * 0.23 / (1e9 * time) ... > $ perf stat -a -e rapl/rapl-energy-cores/,rapl/rapl-energy-pkg/ -I 1000 sleep 10 > time counts events > 1.000345931 772 278 493 rapl/rapl-energy-cores/ > 1.000345931 55 539 138 560 rapl/rapl-energy-pkg/ > 2.000836387 771 751 936 rapl/rapl-energy-cores/ > 2.000836387 55 326 015 488 rapl/rapl-energy-pkg/ So can we do the Watt conversion in perf tool and make that "counts" output more human-friendly like what those numbers are, to which core/LLC they belong, etc, etc? Thanks. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/