Re: [PATCH v2 7/7] perf expr: Migrate expr ids table to a hashmap

[Jiri Olsa]

On Fri, May 15, 2020 at 09:50:07AM -0700, Ian Rogers wrote:

SNIP

> diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
> index 8b4ce704a68d..f64ab91c432b 100644
> --- a/tools/perf/util/expr.c
> +++ b/tools/perf/util/expr.c
> @@ -4,25 +4,76 @@
>  #include "expr.h"
>  #include "expr-bison.h"
>  #include "expr-flex.h"
> +#include <linux/kernel.h>
>  
>  #ifdef PARSER_DEBUG
>  extern int expr_debug;
>  #endif
>  
> +static size_t key_hash(const void *key, void *ctx __maybe_unused)
> +{
> +	const char *str = (const char *)key;
> +	size_t hash = 0;
> +
> +	while (*str != '\0') {
> +		hash *= 31;
> +		hash += *str;
> +		str++;
> +	}
> +	return hash;
> +}
> +
> +static bool key_equal(const void *key1, const void *key2,
> +		    void *ctx __maybe_unused)
> +{
> +	return !strcmp((const char *)key1, (const char *)key2);

should that be strcasecmp ? would it affect the key_hash as well?

jirka