Commit d73bad06 authored by Andi Kleen's avatar Andi Kleen Committed by Arnaldo Carvalho de Melo
Browse files

perf tools: Expression parser enhancements for metrics 



Enhance the expression parser for more complex metric formulas.

- Support python style IF ELSE operators
- Add an #SMT_On magic variable for formulas that depend on the SMT
status.

Example: 4 *( CPU_CLK_UNHALTED.THREAD_ANY / 2 ) if #SMT_on else cycles

- Support MIN/MAX operations

Example: min(1 , IDQ.MITE_UOPS / ( UPI * 16 * ( ICACHE.HIT + ICACHE.MISSES ) / 4.0 ) )

This is useful to fix up problems caused by multiplexing.

- Support | & ^ operators
- Minor cleanups and fixes
- Support an \ escape for operators. This allows to specify event names
like c2-residency
- Support @ as an alternative for / to be able to specify pmus without
conflicts with operators (like msr/tsc/ as msr@tsc@)

Example: (cstate_core@c3\\-residency@ / msr@tsc@) * 100

Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20170811232634.30465-8-andi@firstfloor.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent de5077c4

tools/perf/tests/expr.c

+5 −0
Original line number Diff line number Diff line
@@ -31,6 +31,11 @@ int test__expr(struct test *t __maybe_unused, int subtest __maybe_unused) 
	ret |= test(&ctx, "(BAR/2)%2", 1);

	ret |= test(&ctx, "1 - -4",  5);

	ret |= test(&ctx, "(FOO-1)*2 + (BAR/2)%2 - -4",  5);

	ret |= test(&ctx, "1-1 | 1", 1);

	ret |= test(&ctx, "1-1 & 1", 0);

	ret |= test(&ctx, "min(1,2) + 1", 2);

	ret |= test(&ctx, "max(1,2) + 1", 3);

	ret |= test(&ctx, "1+1 if 3*4 else 0", 2);



	if (ret)

		return ret;

tools/perf/util/expr.y

+55 −6
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
#include "util/debug.h"

#define IN_EXPR_Y 1

#include "expr.h"

#include "smt.h"

#include <string.h>



#define MAXIDLEN 256
@@ -22,13 +23,15 @@ 


%token <num> NUMBER

%token <id> ID

%token MIN MAX IF ELSE SMT_ON

%left MIN MAX IF

%left '|'

%left '^'

%left '&'

%left '-' '+'

%left '*' '/' '%'

%left NEG NOT

%type <num> expr

%type <num> expr if_expr



%{

static int expr__lex(YYSTYPE *res, const char **pp);
@@ -57,7 +60,12 @@ static int lookup_id(struct parse_ctx *ctx, char *id, double *val) 
%}

%%



all_expr: expr			{ *final_val = $1; }

all_expr: if_expr			{ *final_val = $1; }

	;



if_expr:

	expr IF expr ELSE expr { $$ = $3 ? $1 : $5; }

	| expr

	;



expr:	  NUMBER
@@ -66,13 +74,19 @@ expr: NUMBER 
					YYABORT;

				  }

				}

	| expr '|' expr		{ $$ = (long)$1 | (long)$3; }

	| expr '&' expr		{ $$ = (long)$1 & (long)$3; }

	| expr '^' expr		{ $$ = (long)$1 ^ (long)$3; }

	| expr '+' expr		{ $$ = $1 + $3; }

	| expr '-' expr		{ $$ = $1 - $3; }

	| expr '*' expr		{ $$ = $1 * $3; }

	| expr '/' expr		{ if ($3 == 0) YYABORT; $$ = $1 / $3; }

	| expr '%' expr		{ if ((long)$3 == 0) YYABORT; $$ = (long)$1 % (long)$3; }

	| '-' expr %prec NEG	{ $$ = -$2; }

	| '(' expr ')'		{ $$ = $2; }

	| '(' if_expr ')'	{ $$ = $2; }

	| MIN '(' expr ',' expr ')' { $$ = $3 < $5 ? $3 : $5; }

	| MAX '(' expr ',' expr ')' { $$ = $3 > $5 ? $3 : $5; }

	| SMT_ON		 { $$ = smt_on() > 0; }

	;



%%
@@ -82,13 +96,47 @@ static int expr__symbol(YYSTYPE *res, const char *p, const char **pp) 
	char *dst = res->id;

	const char *s = p;



	while (isalnum(*p) || *p == '_' || *p == '.') {

	if (*p == '#')

		*dst++ = *p++;



	while (isalnum(*p) || *p == '_' || *p == '.' || *p == ':' || *p == '@' || *p == '\\') {

		if (p - s >= MAXIDLEN)

			return -1;

		*dst++ = *p++;

		/*

		 * Allow @ instead of / to be able to specify pmu/event/ without

		 * conflicts with normal division.

		 */

		if (*p == '@')

			*dst++ = '/';

		else if (*p == '\\')

			*dst++ = *++p;

		else

			*dst++ = *p;

		p++;

	}

	*dst = 0;

	*pp = p;

	dst = res->id;

	switch (dst[0]) {

	case 'm':

		if (!strcmp(dst, "min"))

			return MIN;

		if (!strcmp(dst, "max"))

			return MAX;

		break;

	case 'i':

		if (!strcmp(dst, "if"))

			return IF;

		break;

	case 'e':

		if (!strcmp(dst, "else"))

			return ELSE;

		break;

	case '#':

		if (!strcasecmp(dst, "#smt_on"))

			return SMT_ON;

		break;

	}

	return ID;

}
@@ -102,6 +150,7 @@ static int expr__lex(YYSTYPE *res, const char **pp) 
		p++;

	s = p;

	switch (*p++) {

	case '#':

	case 'a' ... 'z':

	case 'A' ... 'Z':

		return expr__symbol(res, p - 1, pp);
@@ -151,7 +200,7 @@ int expr__find_other(const char *p, const char *one, const char ***other, 
			err = 0;

			break;

		}

		if (tok == ID && strcasecmp(one, val.id)) {

		if (tok == ID && (!one || strcasecmp(one, val.id))) {

			if (num_other >= EXPR_MAX_OTHER - 1) {

				pr_debug("Too many extra events in %s\n", orig);

				break;

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