Re: [PATCH 2/2] perf arm-spe: Parse more SPE fields and store source

From: German Gomez
Date: Fri Feb 11 2022 - 11:32:33 EST


Hi Ali,

On 28/01/2022 21:02, Ali Saidi wrote:
> Hi German,
>
> On 28/01/2022 19:20, German Gomez wrote:
>> Hi Ali,
>>
>> [...]
>>> };
>>>
>>> enum arm_spe_op_type {
>>> ARM_SPE_LD = 1 << 0,
>>> ARM_SPE_ST = 1 << 1,
>>> + ARM_SPE_LDST_EXCL = 1 << 2,
>>> + ARM_SPE_LDST_ATOMIC = 1 << 3,
>>> + ARM_SPE_LDST_ACQREL = 1 << 4,

Wondering if we can store this in perf_sample->flags. The values are
defined in "util/event.h" (PERF_IP_*). Maybe we can extend it to allow
doing "sample->flags = PERF_LDST_FLAG_LD | PERF_LDST_FLAG_ATOMIC" and
such.

@Leo do you think that could work?

>>> + ARM_SPE_BR = 1 << 5,
>>> + ARM_SPE_BR_COND = 1 << 6,
>>> + ARM_SPE_BR_IND = 1 << 7,

Seems like we can store BR_COND in the existing "branch-miss" event
(--itrace=b) with:

  sample->flags = PERF_IP_FLAG_BRANCH;
  sample->flags |= PERF_IP_FLAG_CONDITIONAL;
and/or
  sample->flags |= PERF_IP_FLAG_INDIRECT;

PERF_IP_FLAG_INDIRECT doesn't exist yet but we can probably add it.