linux-kernel - [RFC PATCH v4 12/15] perf stat: Handle NMI in hardware-grouping

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Message-ID: <20240209031441.943012-13-weilin.wang@intel.com>
Date: Thu,  8 Feb 2024 19:14:38 -0800
From: weilin.wang@...el.com
To: weilin.wang@...el.com,
	Ian Rogers <irogers@...gle.com>,
	Kan Liang <kan.liang@...ux.intel.com>,
	Namhyung Kim <namhyung@...nel.org>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...hat.com>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Jiri Olsa <jolsa@...nel.org>,
	Adrian Hunter <adrian.hunter@...el.com>
Cc: linux-perf-users@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Perry Taylor <perry.taylor@...el.com>,
	Samantha Alt <samantha.alt@...el.com>,
	Caleb Biggers <caleb.biggers@...el.com>,
	Mark Rutland <mark.rutland@....com>
Subject: [RFC PATCH v4 12/15] perf stat: Handle NMI in hardware-grouping

From: Weilin Wang <weilin.wang@...el.com>

Add an easy nmi watchdog support in grouping. When nmi watchdog is enabled,
we reduce the total num of events could be assigned to one group by 1. A
more efficient solution will be added in later.

Signed-off-by: Weilin Wang <weilin.wang@...el.com>
---
 tools/perf/util/metricgroup.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index 95d3868819e3..f1eb73957765 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -1947,6 +1947,10 @@ static int insert_new_group(struct list_head *head,
 			   size_t num_fixed_counters)
 {
 	INIT_LIST_HEAD(&new_group->event_head);
+	if (sysctl__nmi_watchdog_enabled()) {
+		pr_debug("NMI watchdog is enabled. Reduce num of counters by 1\n");
+		num_counters -= 1;
+	}
 	fill_counter_bitmap(new_group->gp_counters, 0, num_counters);
 	fill_counter_bitmap(new_group->fixed_counters, 0, num_fixed_counters);
 	new_group->taken_alone = false;
-- 
2.42.0