Re: [PATCH v4 03/10] perf parse-events: Add parse_uid_filter helper

[Namhyung Kim]

Hi Ian,

On Wed, Jun 04, 2025 at 10:45:37AM -0700, Ian Rogers wrote:
> Add parse_uid_filter filter as a helper to parse_filter, that
> constructs a uid filter string. As uid filters don't work with
> tracepoint filters, add a is_possible_tp_filter function so the
> tracepoint filter isn't attempted for tracepoint evsels.
> 
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> ---
>  tools/perf/util/parse-events.c | 33 ++++++++++++++++++++++++++++++++-
>  tools/perf/util/parse-events.h |  1 +
>  2 files changed, 33 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index d96adf23dc94..7f34e602fc08 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -25,6 +25,7 @@
>  #include "pmu.h"
>  #include "pmus.h"
>  #include "asm/bug.h"
> +#include "ui/ui.h"
>  #include "util/parse-branch-options.h"
>  #include "util/evsel_config.h"
>  #include "util/event.h"
> @@ -2561,6 +2562,12 @@ foreach_evsel_in_last_glob(struct evlist *evlist,
>  	return 0;
>  }
>  
> +/* Will a tracepoint filter work for str or should a BPF filter be used? */
> +static bool is_possible_tp_filter(const char *str)
> +{
> +	return strstr(str, "uid") == NULL;
> +}
> +
>  static int set_filter(struct evsel *evsel, const void *arg)
>  {
>  	const char *str = arg;
> @@ -2573,7 +2580,7 @@ static int set_filter(struct evsel *evsel, const void *arg)
>  		return -1;
>  	}
>  
> -	if (evsel->core.attr.type == PERF_TYPE_TRACEPOINT) {
> +	if (evsel->core.attr.type == PERF_TYPE_TRACEPOINT && is_possible_tp_filter(str)) {
>  		if (evsel__append_tp_filter(evsel, str) < 0) {
>  			fprintf(stderr,
>  				"not enough memory to hold filter string\n");
> @@ -2609,6 +2616,30 @@ int parse_filter(const struct option *opt, const char *str,
>  					  (const void *)str);
>  }
>  
> +int parse_uid_filter(struct evlist *evlist, uid_t uid)

It failed to build on alpine 3.18.

util/parse-events.h:48:45: error: unknown type name 'uid_t'                     
   48 | int parse_uid_filter(struct evlist *evlist, uid_t uid);                 
      |                                             ^~~~~

I'll add this.

Thanks,
Namhyung


---8<---
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index ab242f6710313993..931780911e071ec6 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -11,6 +11,7 @@
 #include <linux/perf_event.h>
 #include <stdio.h>
 #include <string.h>
+#include <sys/types.h>
 
 struct evsel;
 struct evlist;



> +{
> +	struct option opt = {
> +		.value = &evlist,
> +	};
> +	char buf[128];
> +	int ret;
> +
> +	snprintf(buf, sizeof(buf), "uid == %d", uid);
> +	ret = parse_filter(&opt, buf, /*unset=*/0);
> +	if (ret) {
> +		if (use_browser >= 1) {
> +			/*
> +			 * Use ui__warning so a pop up appears above the
> +			 * underlying BPF error message.
> +			 */
> +			ui__warning("Failed to add UID filtering that uses BPF filtering.\n");
> +		} else {
> +			fprintf(stderr, "Failed to add UID filtering that uses BPF filtering.\n");
> +		}
> +	}
> +	return ret;
> +}
> +
>  static int add_exclude_perf_filter(struct evsel *evsel,
>  				   const void *arg __maybe_unused)
>  {
> diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
> index ab242f671031..46e5a01be61c 100644
> --- a/tools/perf/util/parse-events.h
> +++ b/tools/perf/util/parse-events.h
> @@ -45,6 +45,7 @@ static inline int parse_events(struct evlist *evlist, const char *str,
>  int parse_event(struct evlist *evlist, const char *str);
>  
>  int parse_filter(const struct option *opt, const char *str, int unset);
> +int parse_uid_filter(struct evlist *evlist, uid_t uid);
>  int exclude_perf(const struct option *opt, const char *arg, int unset);
>  
>  enum parse_events__term_val_type {
> -- 
> 2.50.0.rc0.604.gd4ff7b7c86-goog
>