Messages in this thread | | | Date | Mon, 7 Oct 2013 18:19:29 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v1 0/2] perf,x86: add Intel RAPL PMU support |
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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. --
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