linux-kernel - [PATCH v1 2/5] perf stat: Remove print_mixed_hw_group

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250318041442.321230-3-irogers@google.com>
Date: Mon, 17 Mar 2025 21:14:39 -0700
From: Ian Rogers <irogers@...gle.com>
To: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>, 
	Arnaldo Carvalho de Melo <acme@...nel.org>, Namhyung Kim <namhyung@...nel.org>, 
	Mark Rutland <mark.rutland@....com>, 
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>, Jiri Olsa <jolsa@...nel.org>, 
	Ian Rogers <irogers@...gle.com>, Adrian Hunter <adrian.hunter@...el.com>, 
	Kan Liang <kan.liang@...ux.intel.com>, Howard Chu <howardchu95@...il.com>, 
	Weilin Wang <weilin.wang@...el.com>, Levi Yun <yeoreum.yun@....com>, 
	"Dr. David Alan Gilbert" <linux@...blig.org>, Andi Kleen <ak@...ux.intel.com>, 
	James Clark <james.clark@...aro.org>, Dominique Martinet <asmadeus@...ewreck.org>, 
	linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v1 2/5] perf stat: Remove print_mixed_hw_group_error

print_mixed_hw_group_error will print a warning when a group of events
uses different PMUs. This isn't possible to happen as
parse_events__sort_events_and_fix_groups will break groups when this
happens, adding the warning at the start of perf of:

  WARNING: events were regrouped to match PMUs

As the previous mixed group warning can never happen, remove the
associated code.

Signed-off-by: Ian Rogers <irogers@...gle.com>
---
 tools/perf/util/stat-display.c | 31 -------------------------------
 tools/perf/util/stat.h         |  1 -
 2 files changed, 32 deletions(-)

diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c
index f311f1960e29..1751a450f449 100644
--- a/tools/perf/util/stat-display.c
+++ b/tools/perf/util/stat-display.c
@@ -798,30 +798,6 @@ static void abs_printout(struct perf_stat_config *config,
 	print_cgroup(config, os, evsel->cgrp);
 }
 
-static bool is_mixed_hw_group(struct evsel *counter)
-{
-	struct evlist *evlist = counter->evlist;
-	u32 pmu_type = counter->core.attr.type;
-	struct evsel *pos;
-
-	if (counter->core.nr_members < 2)
-		return false;
-
-	evlist__for_each_entry(evlist, pos) {
-		/* software events can be part of any hardware group */
-		if (pos->core.attr.type == PERF_TYPE_SOFTWARE)
-			continue;
-		if (pmu_type == PERF_TYPE_SOFTWARE) {
-			pmu_type = pos->core.attr.type;
-			continue;
-		}
-		if (pmu_type != pos->core.attr.type)
-			return true;
-	}
-
-	return false;
-}
-
 static bool evlist__has_hybrid(struct evlist *evlist)
 {
 	struct evsel *evsel;
@@ -886,8 +862,6 @@ static void printout(struct perf_stat_config *config, struct outstate *os,
 		if (counter->supported) {
 			if (!evlist__has_hybrid(counter->evlist)) {
 				config->print_free_counters_hint = 1;
-				if (is_mixed_hw_group(counter))
-					config->print_mixed_hw_group_error = 1;
 			}
 		}
 	}
@@ -1587,11 +1561,6 @@ static void print_footer(struct perf_stat_config *config)
 "	echo 0 > /proc/sys/kernel/nmi_watchdog\n"
 "	perf stat ...\n"
 "	echo 1 > /proc/sys/kernel/nmi_watchdog\n");
-
-	if (config->print_mixed_hw_group_error)
-		fprintf(output,
-			"The events in group usually have to be from "
-			"the same PMU. Try reorganizing the group.\n");
 }
 
 static void print_percore(struct perf_stat_config *config,
diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
index 2fda9acd7374..1bcd7634bf47 100644
--- a/tools/perf/util/stat.h
+++ b/tools/perf/util/stat.h
@@ -100,7 +100,6 @@ struct perf_stat_config {
 	int			 times;
 	int			 run_count;
 	int			 print_free_counters_hint;
-	int			 print_mixed_hw_group_error;
 	const char		*csv_sep;
 	struct stats		*walltime_nsecs_stats;
 	struct rusage		 ru_data;
-- 
2.49.0.rc1.451.g8f38331e32-goog