[PATCH v2 1/2] perf arm-spe: Use SPE data source for neoverse cores

German Gomez german.gomez at arm.com
Wed Mar 2 03:59:05 PST 2022


Hi Ali,

On 21/02/2022 22:47, Ali Saidi wrote:
> When synthesizing data from SPE, augment the type with source information
> for Arm Neoverse cores. The field is IMPLDEF but the Neoverse cores all use
> the same encoding. I can't find encoding information for any other SPE
> implementations to unify their choices with Arm's thus that is left for
> future work.
>
> This change populates the mem_lvl_num for Neoverse cores instead of the
> deprecated mem_lvl namespace.
>
> Signed-off-by: Ali Saidi <alisaidi at amazon.com>
> ---
>  .../util/arm-spe-decoder/arm-spe-decoder.c    |   1 +
>  .../util/arm-spe-decoder/arm-spe-decoder.h    |  12 ++
>  tools/perf/util/arm-spe.c                     | 106 +++++++++++++++---
>  3 files changed, 104 insertions(+), 15 deletions(-)
>
> diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
> index 5e390a1a79ab..091987dd3966 100644
> --- a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
> +++ b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
> @@ -220,6 +220,7 @@ static int arm_spe_read_record(struct arm_spe_decoder *decoder)
>  
>  			break;
>  		case ARM_SPE_DATA_SOURCE:
> +			decoder->record.source = payload;
>  			break;
>  		case ARM_SPE_BAD:
>  			break;
> diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h
> index 69b31084d6be..c81bf90c0996 100644
> --- a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h
> +++ b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h
> @@ -29,6 +29,17 @@ enum arm_spe_op_type {
>  	ARM_SPE_ST		= 1 << 1,
>  };
>  
> +enum arm_spe_neoverse_data_source {
> +	ARM_SPE_NV_L1D        = 0x0,
> +	ARM_SPE_NV_L2         = 0x8,
> +	ARM_SPE_NV_PEER_CORE  = 0x9,
> +	ARM_SPE_NV_LCL_CLSTR  = 0xa,
> +	ARM_SPE_NV_SYS_CACHE  = 0xb,
> +	ARM_SPE_NV_PEER_CLSTR = 0xc,
> +	ARM_SPE_NV_REMOTE     = 0xd,
> +	ARM_SPE_NV_DRAM       = 0xe,
> +};
> +
>  struct arm_spe_record {
>  	enum arm_spe_sample_type type;
>  	int err;
> @@ -40,6 +51,7 @@ struct arm_spe_record {
>  	u64 virt_addr;
>  	u64 phys_addr;
>  	u64 context_id;
> +	u16 source;
>  };
>  
>  struct arm_spe_insn;
> diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c
> index d2b64e3f588b..e0243c2fed5f 100644
> --- a/tools/perf/util/arm-spe.c
> +++ b/tools/perf/util/arm-spe.c
> @@ -34,6 +34,7 @@
>  #include "arm-spe-decoder/arm-spe-decoder.h"
>  #include "arm-spe-decoder/arm-spe-pkt-decoder.h"
>  
> +#include <../../../arch/arm64/include/asm/cputype.h>
>  #define MAX_TIMESTAMP (~0ULL)
>  
>  struct arm_spe {
> @@ -45,6 +46,7 @@ struct arm_spe {
>  	struct perf_session		*session;
>  	struct machine			*machine;
>  	u32				pmu_type;
> +	u64				midr;
>  
>  	struct perf_tsc_conversion	tc;
>  
> @@ -399,33 +401,103 @@ static bool arm_spe__is_memory_event(enum arm_spe_sample_type type)
>  	return false;
>  }
>  
> -static u64 arm_spe__synth_data_source(const struct arm_spe_record *record)
> -{
> -	union perf_mem_data_src	data_src = { 0 };
> +static const struct midr_range neoverse_spe[] = {
> +	MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N1),
> +	MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2),
> +	{},
> +};
>  
> -	if (record->op == ARM_SPE_LD)
> -		data_src.mem_op = PERF_MEM_OP_LOAD;
> -	else
> -		data_src.mem_op = PERF_MEM_OP_STORE;
>  
> +static void arm_spe__synth_data_source_neoverse(const struct arm_spe_record *record,
> +						union perf_mem_data_src *data_src)
> +{
> +	switch (record->source) {
> +	case ARM_SPE_NV_L1D:
> +		data_src->mem_lvl = PERF_MEM_LVL_HIT;

I understand mem_lvl is deprecated but shouldn't we add the level bits here as well for backwards compat?

> +		data_src->mem_lvl_num = PERF_MEM_LVLNUM_L1;
> +		break;
> +	case ARM_SPE_NV_L2:
> +		data_src->mem_lvl = PERF_MEM_LVL_HIT;
> +		data_src->mem_lvl_num = PERF_MEM_LVLNUM_L2;
> +		break;
> +	case ARM_SPE_NV_PEER_CORE:
> +		data_src->mem_lvl = PERF_MEM_LVL_HIT;
> +		data_src->mem_snoop = PERF_MEM_SNOOP_HITM;
> +		data_src->mem_lvl_num = PERF_MEM_LVLNUM_ANY_CACHE;
> +		break;
> +	/*
> +	 * We don't know if this is L1, L2, or even L3 (for the cases the system
> +	 * has an L3, but we do know it was a cache-2-cache transfer, so set
> +	 * SNOOP_HITM
> +	 */
> +	case ARM_SPE_NV_LCL_CLSTR:
> +	case ARM_SPE_NV_PEER_CLSTR:
> +		data_src->mem_lvl = PERF_MEM_LVL_HIT;
> +		data_src->mem_snoop = PERF_MEM_SNOOP_HITM;
> +		data_src->mem_lvl_num = PERF_MEM_LVLNUM_ANY_CACHE;
> +		break;
> +	/*
> +	 * System cache is assumed to be L4, as cluster cache (if it exists)
> +	 * would be L3 cache on Neoverse platforms
> +	 */
> +	case ARM_SPE_NV_SYS_CACHE:
> +		data_src->mem_lvl = PERF_MEM_LVL_HIT;
> +		data_src->mem_lvl_num = PERF_MEM_LVLNUM_L4;
> +		break;
> +	/*
> +	 * We don't know what level it hit in, except it came from the other
> +	 * socket
> +	 */
> +	case ARM_SPE_NV_REMOTE:
> +		data_src->mem_snoop = PERF_MEM_SNOOP_HITM;
> +		data_src->mem_remote = PERF_MEM_REMOTE_REMOTE;
> +		break;
> +	case ARM_SPE_NV_DRAM:
> +		data_src->mem_lvl = PERF_MEM_LVL_HIT;
> +		data_src->mem_lvl_num = PERF_MEM_LVLNUM_RAM;
> +		break;
> +	default:
> +		break;
> +	}
> +}
> +
> +static void arm_spe__synth_data_source_generic(const struct arm_spe_record *record,
> +						union perf_mem_data_src *data_src)
> +{
>  	if (record->type & (ARM_SPE_LLC_ACCESS | ARM_SPE_LLC_MISS)) {
> -		data_src.mem_lvl = PERF_MEM_LVL_L3;
> +		data_src->mem_lvl = PERF_MEM_LVL_L3;
>  
>  		if (record->type & ARM_SPE_LLC_MISS)
> -			data_src.mem_lvl |= PERF_MEM_LVL_MISS;
> +			data_src->mem_lvl |= PERF_MEM_LVL_MISS;
>  		else
> -			data_src.mem_lvl |= PERF_MEM_LVL_HIT;
> +			data_src->mem_lvl |= PERF_MEM_LVL_HIT;
>  	} else if (record->type & (ARM_SPE_L1D_ACCESS | ARM_SPE_L1D_MISS)) {
> -		data_src.mem_lvl = PERF_MEM_LVL_L1;
> +		data_src->mem_lvl = PERF_MEM_LVL_L1;
>  
>  		if (record->type & ARM_SPE_L1D_MISS)
> -			data_src.mem_lvl |= PERF_MEM_LVL_MISS;
> +			data_src->mem_lvl |= PERF_MEM_LVL_MISS;
>  		else
> -			data_src.mem_lvl |= PERF_MEM_LVL_HIT;
> +			data_src->mem_lvl |= PERF_MEM_LVL_HIT;
>  	}
>  
>  	if (record->type & ARM_SPE_REMOTE_ACCESS)
> -		data_src.mem_lvl |= PERF_MEM_LVL_REM_CCE1;
> +		data_src->mem_lvl |= PERF_MEM_LVL_REM_CCE1;
> +}
> +
> +static u64 arm_spe__synth_data_source(const struct arm_spe_record *record, u64 midr)
> +{
> +	union perf_mem_data_src	data_src = { 0 };
> +	bool is_neoverse = is_midr_in_range(midr, neoverse_spe);
> +
> +	if (record->op & ARM_SPE_LD)
> +		data_src.mem_op = PERF_MEM_OP_LOAD;
> +	else
> +		data_src.mem_op = PERF_MEM_OP_STORE;
> +
> +	if (is_neoverse)
> +		arm_spe__synth_data_source_neoverse(record, &data_src);
> +	else
> +		arm_spe__synth_data_source_generic(record, &data_src);
>  
>  	if (record->type & (ARM_SPE_TLB_ACCESS | ARM_SPE_TLB_MISS)) {
>  		data_src.mem_dtlb = PERF_MEM_TLB_WK;
> @@ -446,7 +518,7 @@ static int arm_spe_sample(struct arm_spe_queue *speq)
>  	u64 data_src;
>  	int err;
>  
> -	data_src = arm_spe__synth_data_source(record);
> +	data_src = arm_spe__synth_data_source(record, spe->midr);
>  
>  	if (spe->sample_flc) {
>  		if (record->type & ARM_SPE_L1D_MISS) {
> @@ -796,6 +868,10 @@ static int arm_spe_process_event(struct perf_session *session,
>  	u64 timestamp;
>  	struct arm_spe *spe = container_of(session->auxtrace,
>  			struct arm_spe, auxtrace);
> +	const char *cpuid = perf_env__cpuid(session->evlist->env);
> +	u64 midr = strtol(cpuid, NULL, 16);
> +
> +	spe->midr = midr;

I think this midr setup belongs in the arm_spe_process_auxtrace_info callback instead.

Thanks,
German

>  
>  	if (dump_trace)
>  		return 0;



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