Re: [PATCH v1] perf jevents: Drop or simplify small integer values

["Liang, Kan" <kan.liang@linux.intel.com>]

On 2024-01-31 3:14 p.m., Ian Rogers wrote:
> Prior to this patch '0' would be dropped as the config values default
> to 0. Some json values are hex and the string '0' wouldn't match '0x0'
> as zero. Add a more robust is_zero test to drop these event terms.
> 
> When encoding numbers as hex, if the number is between 0 and 9
> inclusive then don't add a 0x prefix.
> 
> Update test expectations for these changes.
> 
> On x86 this reduces the event/metric C string by 58,411 bytes.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>

Reviewed-by: Kan Liang <kan.liang@linux.intel.com>

Thanks,
Kan
> ---
>  tools/perf/pmu-events/jevents.py | 23 ++++++++++++++++++++---
>  tools/perf/tests/pmu-events.c    | 22 +++++++++++-----------
>  2 files changed, 31 insertions(+), 14 deletions(-)
> 
> diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
> index 53ab050c8fa4..2c7e5d61ce92 100755
> --- a/tools/perf/pmu-events/jevents.py
> +++ b/tools/perf/pmu-events/jevents.py
> @@ -203,7 +203,7 @@ class JsonEvent:
>  
>      def llx(x: int) -> str:
>        """Convert an int to a string similar to a printf modifier of %#llx."""
> -      return '0' if x == 0 else hex(x)
> +      return str(x) if x >= 0 and x < 10 else hex(x)
>  
>      def fixdesc(s: str) -> str:
>        """Fix formatting issue for the desc string."""
> @@ -294,6 +294,23 @@ class JsonEvent:
>        }
>        return table[unit] if unit in table else f'uncore_{unit.lower()}'
>  
> +    def is_zero(val: str) -> bool:
> +        try:
> +            if val.startswith('0x'):
> +                return int(val, 16) == 0
> +            else:
> +                return int(val) == 0
> +        except e:
> +            return False
> +
> +    def canonicalize_value(val: str) -> str:
> +        try:
> +            if val.startswith('0x'):
> +                return llx(int(val, 16))
> +            return str(int(val))
> +        except e:
> +            return val
> +
>      eventcode = 0
>      if 'EventCode' in jd:
>        eventcode = int(jd['EventCode'].split(',', 1)[0], 0)
> @@ -358,8 +375,8 @@ class JsonEvent:
>          ('RdWrMask', 'rdwrmask='),
>      ]
>      for key, value in event_fields:
> -      if key in jd and jd[key] != '0':
> -        event += ',' + value + jd[key]
> +      if key in jd and not is_zero(jd[key]):
> +        event += f',{value}{canonicalize_value(jd[key])}'
>      if filter:
>        event += f',{filter}'
>      if msr:
> diff --git a/tools/perf/tests/pmu-events.c b/tools/perf/tests/pmu-events.c
> index a56d32905743..47a7c3277540 100644
> --- a/tools/perf/tests/pmu-events.c
> +++ b/tools/perf/tests/pmu-events.c
> @@ -70,7 +70,7 @@ static const struct perf_pmu_test_event segment_reg_loads_any = {
>  	.event = {
>  		.pmu = "default_core",
>  		.name = "segment_reg_loads.any",
> -		.event = "event=0x6,period=200000,umask=0x80",
> +		.event = "event=6,period=200000,umask=0x80",
>  		.desc = "Number of segment register loads",
>  		.topic = "other",
>  	},
> @@ -82,7 +82,7 @@ static const struct perf_pmu_test_event dispatch_blocked_any = {
>  	.event = {
>  		.pmu = "default_core",
>  		.name = "dispatch_blocked.any",
> -		.event = "event=0x9,period=200000,umask=0x20",
> +		.event = "event=9,period=200000,umask=0x20",
>  		.desc = "Memory cluster signals to block micro-op dispatch for any reason",
>  		.topic = "other",
>  	},
> @@ -94,11 +94,11 @@ static const struct perf_pmu_test_event eist_trans = {
>  	.event = {
>  		.pmu = "default_core",
>  		.name = "eist_trans",
> -		.event = "event=0x3a,period=200000,umask=0x0",
> +		.event = "event=0x3a,period=200000",
>  		.desc = "Number of Enhanced Intel SpeedStep(R) Technology (EIST) transitions",
>  		.topic = "other",
>  	},
> -	.alias_str = "event=0x3a,period=0x30d40,umask=0",
> +	.alias_str = "event=0x3a,period=0x30d40",
>  	.alias_long_desc = "Number of Enhanced Intel SpeedStep(R) Technology (EIST) transitions",
>  };
>  
> @@ -128,7 +128,7 @@ static const struct perf_pmu_test_event *core_events[] = {
>  static const struct perf_pmu_test_event uncore_hisi_ddrc_flux_wcmd = {
>  	.event = {
>  		.name = "uncore_hisi_ddrc.flux_wcmd",
> -		.event = "event=0x2",
> +		.event = "event=2",
>  		.desc = "DDRC write commands",
>  		.topic = "uncore",
>  		.long_desc = "DDRC write commands",
> @@ -156,13 +156,13 @@ static const struct perf_pmu_test_event unc_cbo_xsnp_response_miss_eviction = {
>  static const struct perf_pmu_test_event uncore_hyphen = {
>  	.event = {
>  		.name = "event-hyphen",
> -		.event = "event=0xe0,umask=0x00",
> +		.event = "event=0xe0",
>  		.desc = "UNC_CBO_HYPHEN",
>  		.topic = "uncore",
>  		.long_desc = "UNC_CBO_HYPHEN",
>  		.pmu = "uncore_cbox",
>  	},
> -	.alias_str = "event=0xe0,umask=0",
> +	.alias_str = "event=0xe0",
>  	.alias_long_desc = "UNC_CBO_HYPHEN",
>  	.matching_pmu = "uncore_cbox_0",
>  };
> @@ -170,13 +170,13 @@ static const struct perf_pmu_test_event uncore_hyphen = {
>  static const struct perf_pmu_test_event uncore_two_hyph = {
>  	.event = {
>  		.name = "event-two-hyph",
> -		.event = "event=0xc0,umask=0x00",
> +		.event = "event=0xc0",
>  		.desc = "UNC_CBO_TWO_HYPH",
>  		.topic = "uncore",
>  		.long_desc = "UNC_CBO_TWO_HYPH",
>  		.pmu = "uncore_cbox",
>  	},
> -	.alias_str = "event=0xc0,umask=0",
> +	.alias_str = "event=0xc0",
>  	.alias_long_desc = "UNC_CBO_TWO_HYPH",
>  	.matching_pmu = "uncore_cbox_0",
>  };
> @@ -184,7 +184,7 @@ static const struct perf_pmu_test_event uncore_two_hyph = {
>  static const struct perf_pmu_test_event uncore_hisi_l3c_rd_hit_cpipe = {
>  	.event = {
>  		.name = "uncore_hisi_l3c.rd_hit_cpipe",
> -		.event = "event=0x7",
> +		.event = "event=7",
>  		.desc = "Total read hits",
>  		.topic = "uncore",
>  		.long_desc = "Total read hits",
> @@ -265,7 +265,7 @@ static const struct perf_pmu_test_event sys_ccn_pmu_read_cycles = {
>  static const struct perf_pmu_test_event sys_cmn_pmu_hnf_cache_miss = {
>  	.event = {
>  		.name = "sys_cmn_pmu.hnf_cache_miss",
> -		.event = "eventid=0x1,type=0x5",
> +		.event = "eventid=1,type=5",
>  		.desc = "Counts total cache misses in first lookup result (high priority)",
>  		.topic = "uncore",
>  		.pmu = "uncore_sys_cmn_pmu",