Re: [PATCH 5/5] perf: arm_spe: Decode SVE events

[André Przywara]

On 27/09/2020 04:30, Leo Yan wrote:

Hi Leo,

> On Tue, Sep 22, 2020 at 11:12:25AM +0100, Andre Przywara wrote:
>> The Scalable Vector Extension (SVE) is an ARMv8 architecture extension
>> that introduces very long vector operations (up to 2048 bits).
>> The SPE profiling feature can tag SVE instructions with additional
>> properties like predication or the effective vector length.
>>
>> Decode the new operation type bits in the SPE decoder to allow the perf
>> tool to correctly report about SVE instructions.
>>
>> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
>> ---
>>  .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 48 ++++++++++++++++++-
>>  1 file changed, 47 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
>> index a033f34846a6..f0c369259554 100644
>> --- a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
>> +++ b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
>> @@ -372,8 +372,35 @@ int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
>>  	}
>>  	case ARM_SPE_OP_TYPE:
>>  		switch (idx) {
>> -		case 0:	return snprintf(buf, buf_len, "%s", payload & 0x1 ?
>> +		case 0: {
>> +			size_t blen = buf_len;
>> +
>> +			if ((payload & 0x89) == 0x08) {
>> +				ret = snprintf(buf, buf_len, "SVE");
>> +				buf += ret;
>> +				blen -= ret;
>> +				if (payload & 0x2)
>> +					ret = snprintf(buf, buf_len, " FP");
>> +				else
>> +					ret = snprintf(buf, buf_len, " INT");
>> +				buf += ret;
>> +				blen -= ret;
>> +				if (payload & 0x4) {
>> +					ret = snprintf(buf, buf_len, " PRED");
>> +					buf += ret;
>> +					blen -= ret;
>> +				}
>> +				/* Bits [7..4] encode the vector length */
>> +				ret = snprintf(buf, buf_len, " EVLEN%d",
>> +					       32 << ((payload >> 4) & 0x7));
>> +				buf += ret;
>> +				blen -= ret;
>> +				return buf_len - blen;
>> +			}
>> +
>> +			return snprintf(buf, buf_len, "%s", payload & 0x1 ?
>>  					"COND-SELECT" : "INSN-OTHER");
>> +			}
>>  		case 1:	{
>>  			size_t blen = buf_len;
>>  
>> @@ -403,6 +430,25 @@ int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
>>  				ret = snprintf(buf, buf_len, " NV-SYSREG");
>>  				buf += ret;
>>  				blen -= ret;
>> +			} else if ((payload & 0x0a) == 0x08) {
>> +				ret = snprintf(buf, buf_len, " SVE");
>> +				buf += ret;
>> +				blen -= ret;
>> +				if (payload & 0x4) {
>> +					ret = snprintf(buf, buf_len, " PRED");
>> +					buf += ret;
>> +					blen -= ret;
>> +				}
>> +				if (payload & 0x80) {
>> +					ret = snprintf(buf, buf_len, " SG");
>> +					buf += ret;
>> +					blen -= ret;
>> +				}
>> +				/* Bits [7..4] encode the vector length */
>> +				ret = snprintf(buf, buf_len, " EVLEN%d",
>> +					       32 << ((payload >> 4) & 0x7));
>> +				buf += ret;
>> +				blen -= ret;
> 
> The changes in this patch has been included in the patch [1].
> 
> So my summary for patches 02 ~ 05, except patch 04, other changes has
> been included in the patch set "perf arm-spe: Refactor decoding &
> dumping flow".

Ah, my sincere apologies, I totally missed Wei's and your series on this
(although I did some research on "prior art").

> I'd like to add your patch 04 into the patch set "perf arm-spe:
> Refactor decoding & dumping flow" and I will respin the patch set v2 on
> the latest perf/core branch and send out to review.
> 
> For patch 01, you could continue to try to land it in the kernel.
> (Maybe consolidate a bit with Wei?).
> 
> Do you think this is okay for you?

Yes, sounds like a plan. So Wei's original series is now fully
integrated into your 13-patch rework, right?

Is "[RESEND,v1,xx/13] ..." the latest revision of your series?
Do you plan on sending a v2 anytime soon? Or shall I do review on the
existing one?

Cheers,
Andre

> 
> [1] https://lore.kernel.org/patchwork/patch/1288413/
> 
>>  			} else if (payload & 0x4) {
>>  				ret = snprintf(buf, buf_len, " SIMD-FP");
>>  				buf += ret;
>> -- 
>> 2.17.1
>>