Commit 9d5da30e authored by James Clark's avatar James Clark Committed by Arnaldo Carvalho de Melo
Browse files

perf jevents: Add a new expression builtin strcmp_cpuid_str() 



This will allow writing formulas that are conditional on a specific
CPU type or CPU version. It calls through to the existing
strcmp_cpuid_str() function in Perf which has a default weak version,
and an arch specific version for x86 and arm64.

The function takes an 'ID' type value, which is a string. But in this
case Arm CPU IDs are hex numbers prefixed with '0x'. metric.py
assumes strings are only used by event names, and that they can't start
with a number ('0'), so an additional change has to be made to the
regex to convert hex numbers back to 'ID' types.

Signed-off-by: default avatarJames Clark <james.clark@arm.com>
Reviewed-by: default avatarJohn Garry <john.g.garry@oracle.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Haixin Yu <yuhaixin.yhx@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nick Forrington <nick.forrington@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Sohom Datta <sohomdatta1@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230816114841.1679234-5-james.clark@arm.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 81f7da54

tools/perf/arch/arm64/util/pmu.c

+1 −17
Original line number Diff line number Diff line
@@ -2,28 +2,12 @@ 


#include <internal/cpumap.h>

#include "../../../util/cpumap.h"

#include "../../../util/header.h"

#include "../../../util/pmu.h"

#include "../../../util/pmus.h"

#include <api/fs/fs.h>

#include <math.h>



static struct perf_pmu *pmu__find_core_pmu(void)

{

	struct perf_pmu *pmu = NULL;



	while ((pmu = perf_pmus__scan_core(pmu))) {

		/*

		 * The cpumap should cover all CPUs. Otherwise, some CPUs may

		 * not support some events or have different event IDs.

		 */

		if (RC_CHK_ACCESS(pmu->cpus)->nr != cpu__max_cpu().cpu)

			return NULL;



		return pmu;

	}

	return NULL;

}



const struct pmu_metrics_table *pmu_metrics_table__find(void)

{

	struct perf_pmu *pmu = pmu__find_core_pmu();

tools/perf/pmu-events/metric.py

+15 −2
Original line number Diff line number Diff line
@@ -413,6 +413,10 @@ def has_event(event: Event) -> Function: 
  # pylint: disable=invalid-name

  return Function('has_event', event)



def strcmp_cpuid_str(event: str) -> Function:

  # pylint: disable=redefined-builtin

  # pylint: disable=invalid-name

  return Function('strcmp_cpuid_str', event)



class Metric:

  """An individual metric that will specifiable on the perf command line."""
@@ -541,14 +545,23 @@ def ParsePerfJson(orig: str) -> Expression: 
  """

  # pylint: disable=eval-used

  py = orig.strip()

  # First try to convert everything that looks like a string (event name) into Event(r"EVENT_NAME").

  # This isn't very selective so is followed up by converting some unwanted conversions back again

  py = re.sub(r'([a-zA-Z][^-+/\* \\\(\),]*(?:\\.[^-+/\* \\\(\),]*)*)',

              r'Event(r"\1")', py)

  # If it started with a # it should have been a literal, rather than an event name

  py = re.sub(r'#Event\(r"([^"]*)"\)', r'Literal("#\1")', py)

  # Convert accidentally converted hex constants ("0Event(r"xDEADBEEF)"") back to a constant,

  # but keep it wrapped in Event(), otherwise Python drops the 0x prefix and it gets interpreted as

  # a double by the Bison parser

  py = re.sub(r'0Event\(r"[xX]([0-9a-fA-F]*)"\)', r'Event("0x\1")', py)

  # Convert accidentally converted scientific notation constants back

  py = re.sub(r'([0-9]+)Event\(r"(e[0-9]+)"\)', r'\1\2', py)

  keywords = ['if', 'else', 'min', 'max', 'd_ratio', 'source_count', 'has_event']

  # Convert all the known keywords back from events to just the keyword

  keywords = ['if', 'else', 'min', 'max', 'd_ratio', 'source_count', 'has_event', 'strcmp_cpuid_str',

              'cpuid_not_more_than']

  for kw in keywords:

    py = re.sub(rf'Event\(r"{kw}"\)', kw, py)



  try:

    parsed = ast.parse(py, mode='eval')

  except SyntaxError as e:

tools/perf/util/expr.c

+18 −0
Original line number Diff line number Diff line
@@ -13,6 +13,8 @@ 
#include <util/expr-bison.h>

#include <util/expr-flex.h>

#include "util/hashmap.h"

#include "util/header.h"

#include "util/pmu.h"

#include "smt.h"

#include "tsc.h"

#include <api/fs/fs.h>
@@ -495,3 +497,19 @@ double expr__has_event(const struct expr_parse_ctx *ctx, bool compute_ids, const 
	evlist__delete(tmp);

	return ret;

}



double expr__strcmp_cpuid_str(const struct expr_parse_ctx *ctx __maybe_unused,

		       bool compute_ids __maybe_unused, const char *test_id)

{

	double ret;

	struct perf_pmu *pmu = pmu__find_core_pmu();

	char *cpuid = perf_pmu__getcpuid(pmu);



	if (!cpuid)

		return NAN;



	ret = !strcmp_cpuid_str(test_id, cpuid);



	free(cpuid);

	return ret;

}

tools/perf/util/expr.h

+1 −0
Original line number Diff line number Diff line
@@ -55,5 +55,6 @@ double expr_id_data__value(const struct expr_id_data *data); 
double expr_id_data__source_count(const struct expr_id_data *data);

double expr__get_literal(const char *literal, const struct expr_scanner_ctx *ctx);

double expr__has_event(const struct expr_parse_ctx *ctx, bool compute_ids, const char *id);

double expr__strcmp_cpuid_str(const struct expr_parse_ctx *ctx, bool compute_ids, const char *id);



#endif

tools/perf/util/expr.l

+1 −0
Original line number Diff line number Diff line
@@ -114,6 +114,7 @@ if { return IF; } 
else		{ return ELSE; }

source_count	{ return SOURCE_COUNT; }

has_event	{ return HAS_EVENT; }

strcmp_cpuid_str	{ return STRCMP_CPUID_STR; }

{literal}	{ return literal(yyscanner, sctx); }

{number}	{ return value(yyscanner); }

{symbol}	{ return str(yyscanner, ID, sctx->runtime); }