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

From: Leo Yan <leo.yan@linaro.org>
To: Andre Przywara <andre.przywara@arm.com>
Cc: Will Deacon <will@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Tan Xiaojun <tanxiaojun@huawei.com>,
	James Clark <james.clark@arm.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/5] perf: arm_spe: Decode SVE events
Date: Sun, 27 Sep 2020 11:30:35 +0800	[thread overview]
Message-ID: <20200927033035.GE9677@leoy-ThinkPad-X240s> (raw)
In-Reply-To: <20200922101225.183554-6-andre.przywara@arm.com>

Hi Andre,

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@arm.com>
> ---
>  .../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".

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?

Thanks,
Leo

[1] https://lore.kernel.org/patchwork/patch/1288413/

>  			} else if (payload & 0x4) {
>  				ret = snprintf(buf, buf_len, " SIMD-FP");
>  				buf += ret;
> -- 
> 2.17.1
> 