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

Adrian Hunter posted 2 patches 4 years, 5 months ago
arch/x86/events/intel/pt.c       | 16 ++++++++++++++++
arch/x86/include/asm/intel_pt.h  |  2 ++
arch/x86/include/asm/msr-index.h |  2 ++
3 files changed, 20 insertions(+)
[PATCH V2 0/2] perf/x86/intel/pt: Add support for event tracing and TNT disabling
Posted by Adrian Hunter 4 years, 5 months ago
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.

Tools patches are being sent in a separate patch set, but can be found
here:

	https://github.com/ahunter6/linux/tree/event-trace


Changes in V2:

	Add my SOB


Alexander Shishkin (2):
      perf/x86/intel/pt: Add a capability and config bit for event tracing
      perf/x86/intel/pt: Add a capability and config bit for disabling TNTs

 arch/x86/events/intel/pt.c       | 16 ++++++++++++++++
 arch/x86/include/asm/intel_pt.h  |  2 ++
 arch/x86/include/asm/msr-index.h |  2 ++
 3 files changed, 20 insertions(+)


Regards
Adrian 
Re: [PATCH V2 0/2] perf/x86/intel/pt: Add support for event tracing and TNT disabling
Posted by Adrian Hunter 4 years, 4 months ago
On 26/01/2022 12:48, 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.
> 
> Tools patches are being sent in a separate patch set, but can be found
> here:
> 
> 	https://github.com/ahunter6/linux/tree/event-trace
> 
> 
> Changes in V2:
> 
> 	Add my SOB

Ping


> 
> 
> Alexander Shishkin (2):
>       perf/x86/intel/pt: Add a capability and config bit for event tracing
>       perf/x86/intel/pt: Add a capability and config bit for disabling TNTs
> 
>  arch/x86/events/intel/pt.c       | 16 ++++++++++++++++
>  arch/x86/include/asm/intel_pt.h  |  2 ++
>  arch/x86/include/asm/msr-index.h |  2 ++
>  3 files changed, 20 insertions(+)
> 
> 
> Regards
> Adrian 
> 

Re: [PATCH V2 0/2] perf/x86/intel/pt: Add support for event tracing and TNT disabling
Posted by Adrian Hunter 4 years, 4 months ago
On 08/02/2022 08:28, Adrian Hunter wrote:
> On 26/01/2022 12:48, 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.
>>
>> Tools patches are being sent in a separate patch set, but can be found
>> here:
>>
>> 	https://github.com/ahunter6/linux/tree/event-trace
>>
>>
>> Changes in V2:
>>
>> 	Add my SOB
> 
> Ping

Any comments on these patches?

> 
> 
>>
>>
>> Alexander Shishkin (2):
>>       perf/x86/intel/pt: Add a capability and config bit for event tracing
>>       perf/x86/intel/pt: Add a capability and config bit for disabling TNTs
>>
>>  arch/x86/events/intel/pt.c       | 16 ++++++++++++++++
>>  arch/x86/include/asm/intel_pt.h  |  2 ++
>>  arch/x86/include/asm/msr-index.h |  2 ++
>>  3 files changed, 20 insertions(+)
>>
>>
>> Regards
>> Adrian 
>>
> 

Re: [PATCH V2 0/2] perf/x86/intel/pt: Add support for event tracing and TNT disabling
Posted by Peter Zijlstra 4 years, 4 months ago
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?
Re: [PATCH V2 0/2] perf/x86/intel/pt: Add support for event tracing and TNT disabling
Posted by Adrian Hunter 4 years, 4 months ago
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.
Re: [PATCH V2 0/2] perf/x86/intel/pt: Add support for event tracing and TNT disabling
Posted by Peter Zijlstra 4 years, 4 months ago
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.
Re: [PATCH V2 0/2] perf/x86/intel/pt: Add support for event tracing and TNT disabling
Posted by Peter Zijlstra 4 years, 4 months ago
On Wed, Jan 26, 2022 at 12:48:13PM +0200, Adrian Hunter wrote:
> Alexander Shishkin (2):
>       perf/x86/intel/pt: Add a capability and config bit for event tracing
>       perf/x86/intel/pt: Add a capability and config bit for disabling TNTs
> 
>  arch/x86/events/intel/pt.c       | 16 ++++++++++++++++
>  arch/x86/include/asm/intel_pt.h  |  2 ++
>  arch/x86/include/asm/msr-index.h |  2 ++
>  3 files changed, 20 insertions(+)

patches look Ok otherwise, I'll queue then in perf/core