Messages in this thread | | | Date | Fri, 21 May 2010 00:46:25 +0200 | From | Robert Richter <> | Subject | Re: [PATCH 1/7] perf: introduce raw_type attribute to specify the type of a raw sample |
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On 19.05.10 18:02:40, Corey Ashford wrote:
> > perf record -e r186A:IBS_FETCH ... > > perf record -e r0:IBS_FETCH -c 100000 ... > > Should this raw value have been 186A0 instead of 186A?
This is the 20 bit value of the cycle count, but only bits 19:4 are encoded in bits 15:0 of the raw ibs register. Lower 4 bits of the cycle count must be null and thus not pushed to the register. The raw register setup is correct.
> Where is the named type translation coming from? Is this something > that needs to be hard-coded into perf?
I was thinking of an enum or macro definition for the values in the kernel. A name mapping table could be implemented at least in the userspace, if needed maybe also in the kernel.
> Have you looked at Lin Ming's patch series? I think it offers > another way to support IBS and other arch-specific and off-chip PMUs > in a more general way, though it's not quite fully-baked yet.
Yes, this could be an option too. The proposal was some days ago and a little hidden in its subject, so I missed it first. But the concept of registering a pmu feature looks good and could be an alternative to the raw_value approach.
-Robert
-- Advanced Micro Devices, Inc. Operating System Research Center email: robert.richter@amd.com
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