Re: [PATCH v5 5/6] perf vendor events arm64: Update stall_slot workaround for N2 r0p3

[John Garry <john.g.garry@oracle.com>]

>     try:
>       parsed = ast.parse(py, mode='eval')
>     except SyntaxError as e:
> diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
> index 7410a165f68b..0985a3cbc6f9 100644
> --- a/tools/perf/util/expr.c
> +++ b/tools/perf/util/expr.c
> @@ -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);

It seems that strcmp_cpuid_str() is only added in arm64 arch code - 
should there be a weak version for other archs?

> +
> +	free(cpuid);
> +	return ret;
> +}
> diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h
> index 3c1e49b3e35d..c0cec29ddc29 100644
> --- a/tools/perf/util/expr.h
> +++ b/tools/perf/util/expr.h
> @@ -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
> diff --git a/tools/perf/util/expr.l b/tools/perf/util/expr.l
> index dbb117414710..0feef0726c48 100644
> --- a/tools/perf/util/expr.l
> +++ b/tools/perf/util/expr.l
> @@ -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); }
> diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
> index 65d54a6f29ad..6c93b358cc2d 100644
> --- a/tools/perf/util/expr.y
> +++ b/tools/perf/util/expr.y
> @@ -39,7 +39,7 @@ int expr_lex(YYSTYPE * yylval_param , void *yyscanner);
>   	} ids;
>   }
>   
> -%token ID NUMBER MIN MAX IF ELSE LITERAL D_RATIO SOURCE_COUNT HAS_EVENT EXPR_ERROR
> +%token ID NUMBER MIN MAX IF ELSE LITERAL D_RATIO SOURCE_COUNT HAS_EVENT STRCMP_CPUID_STR EXPR_ERROR
>   %left MIN MAX IF
>   %left '|'
>   %left '^'
> @@ -207,6 +207,12 @@ expr: NUMBER
>   	$$.ids = NULL;
>   	free($3);
>   }
> +| STRCMP_CPUID_STR '(' ID ')'
> +{
> +	$$.val = expr__strcmp_cpuid_str(ctx, compute_ids, $3);
> +	$$.ids = NULL;
> +	free($3);
> +}
>   | expr '|' expr
>   {
>   	if (is_const($1.val) && is_const($3.val)) {
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index b6654b9f55d2..b6948021fe29 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -1779,3 +1779,20 @@ void perf_pmu__delete(struct perf_pmu *pmu)
>   	zfree(&pmu->alias_name);
>   	free(pmu);
>   }
> +
> +struct perf_pmu *pmu__find_core_pmu(void)

Why was this relocated? I don't see anywhere changed which referenced 
pmu__find_core_pmu() in this patch

> +{
> +	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;
> +}
> diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
> index 203b92860e3c..580b8d65bd65 100644
> --- a/tools/perf/util/pmu.h
> +++ b/tools/perf/util/pmu.h
> @@ -288,5 +288,6 @@ int perf_pmu__pathname_fd(int dirfd, const char *pmu_name, const char *filename,
>   struct perf_pmu *perf_pmu__lookup(struct list_head *pmus, int dirfd, const char *lookup_name);
>   struct perf_pmu *perf_pmu__create_placeholder_core_pmu(struct list_head *core_pmus);
>   void perf_pmu__delete(struct perf_pmu *pmu);
> +struct perf_pmu *pmu__find_core_pmu(void);
>   
>   #endif /* __PMU_H */