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From:   Alexey Budankov <alexey.budankov@linux.intel.com>
Subject: Re: [RFC 0/5] perf: Per PMU access controls (paranoid setting)
To:     Jann Horn <jannh@google.com>
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Date:   Mon, 1 Oct 2018 09:25:42 +0300
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Hello Jann,

> On Fri, Sep 28, 2018 at 11:22:37PM +0200, Jann Horn wrote:
<SNIP>
>>
>> <blasphemy>
>> Is that true? IIRC if you want to use the perf tools after a kernel
>> update, you have to install a new version of perf anyway, no?

There are usages in production where perf_event_open() syscall 
accompanied with read(), mmap() etc. is embedded into application 
on per-thread basis and is used for self monitoring and dynamic 
execution tuning.

There are also other Perf tools around that, for example, are 
statically linked and then used as on Linux as on Android.

Backward compatibility does matter in these cases.

Thanks,
Alexey