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

From: Peter Zijlstra
Date: Tue Feb 15 2022 - 10:51:55 EST


On Tue, Feb 15, 2022 at 05:40:45PM +0200, Adrian Hunter wrote:
> 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.

Thanks, updated that Changelog.