Re: [REGRESSION][BISECT] perf/core: Remove pmu linear searching code

[Ravi Bangoria]

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