Re: [PATCH V2 0/2] perf/x86/intel/pt: Add support for event tracing and TNT disabling

[Adrian Hunter]

On 15/02/2022 17:35, Peter Zijlstra wrote:
> On Wed, Jan 26, 2022 at 12:48:13PM +0200, Adrian Hunter wrote:
>> Hi
>>
>> As of Intel SDM (https://www.intel.com/sdm) version 076, there are 2 new
>> Intel PT features called Event Trace and TNT-Disable.
>>
>> Event Trace exposes details about asynchronous events such as interrupts
>> and VM-Entry/Exit.
>>
>> TNT-Disable disables TNT packets to reduce the tracing overhead, but with
>> the result that exact control flow information is lost.
> 
> What's a TNT?

The TNT packet indicates whether conditional branches were taken
or not taken.