[REGRESSION][BISECT] perf/core: Remove pmu linear searching code
Ravi Bangoria
ravi.bangoria at amd.com
Mon Jun 5 02:43:24 PDT 2023
On 05-Jun-23 3:04 PM, Peter Zijlstra wrote:
> On Mon, Jun 05, 2023 at 11:27:31AM +0200, Peter Zijlstra wrote:
>> On Mon, Jun 05, 2023 at 08:10:15AM +0100, Mark Rutland wrote:
>>
>>> How does this work on x86? Do you have pseudo-PMUs for PERF_TYPE_HARDWARE and
>>> PERF_TYPE_RAW ?
>>
>> Generic code maps TYPE_HARDWARE and TYPE_HW_CACHE to TYPE_RAW for a
>> first go, only if that fails it will try the actual type.
>>
>> And x86 has the (first) CPU PMU has TYPE_RAW, on hybrid, it will
>> transparently pick the right actual PMU.
>
> Oh, I might've misread that last bit.. TYPE_RAW is always the big core,
> it will not magic the thing. If you want little events you gotta
> manually find the little pmu.
"manually find the little pmu" ... which was being done by linear searching?
Thanks,
Ravi
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