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Subject: Re: [PATCH 2/2] perf arm-spe: Parse more SPE fields and store source
To:     Ali Saidi <alisaidi@amazon.com>, leo.yan@linaro.org
Cc:     acme@kernel.org, alexander.shishkin@linux.intel.com,
        andrew.kilroy@arm.com, benh@kernel.crashing.org,
        james.clark@arm.com, john.garry@huawei.com, jolsa@redhat.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-perf-users@vger.kernel.org, mark.rutland@arm.com,
        mathieu.poirier@linaro.org, mingo@redhat.com, namhyung@kernel.org,
        peterz@infradead.org, will@kernel.org
References: <b1b3697d-4a0a-d041-5cbd-e08fec9e658c@arm.com>
 <20220128210245.4628-1-alisaidi@amazon.com>
From:   German Gomez <german.gomez@arm.com>
Message-ID: <7eca7a1d-a5a2-2aab-b3cf-5d83cb8ccf4f@arm.com>
Date:   Fri, 11 Feb 2022 16:31:40 +0000
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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.