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From: Ian Rogers <irogers@google.com>
To: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
	James Clark <james.clark@arm.com>,
	Kees Cook <keescook@chromium.org>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Riccardo Mancini <rickyman7@gmail.com>,
	German Gomez <german.gomez@arm.com>,
	Colin Ian King <colin.king@intel.com>,
	Song Liu <songliubraving@fb.com>,
	Dave Marchevsky <davemarchevsky@fb.com>,
	Athira Rajeev <atrajeev@linux.vnet.ibm.com>,
	Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>,
	Leo Yan <leo.yan@linaro.org>,
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Stephane Eranian <eranian@google.com>, Ian Rogers <irogers@google.com>
Subject: [PATCH v2 3/6] perf cpumap: Compute mask size in constant time
Date: Tue, 14 Jun 2022 07:33:50 -0700	[thread overview]
Message-ID: <20220614143353.1559597-4-irogers@google.com> (raw)
In-Reply-To: <20220614143353.1559597-1-irogers@google.com>

perf_cpu_map__max computes the cpumap's maximum value, no need to
iterate over all values.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/synthetic-events.c | 13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
index b8a42a096502..0d87df20ec44 100644
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c
@@ -1213,18 +1213,7 @@ static size_t cpus_size(const struct perf_cpu_map *map)
 
 static size_t mask_size(const struct perf_cpu_map *map, int *max)
 {
-	int i;
-
-	*max = 0;
-
-	for (i = 0; i < perf_cpu_map__nr(map); i++) {
-		/* bit position of the cpu is + 1 */
-		int bit = perf_cpu_map__cpu(map, i).cpu + 1;
-
-		if (bit > *max)
-			*max = bit;
-	}
-
+	*max = perf_cpu_map__max(map).cpu;
 	return sizeof(struct perf_record_record_cpu_map) + BITS_TO_LONGS(*max) * sizeof(long);
 }
 
-- 
2.36.1.476.g0c4daa206d-goog


  parent reply	other threads:[~2022-06-14 14:35 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-14 14:33 [PATCH v2 0/6] Corrections to cpu map event encoding Ian Rogers
2022-06-14 14:33 ` [PATCH v2 1/6] perf cpumap: Const map for max Ian Rogers
2022-06-14 14:33 ` [PATCH v2 2/6] perf cpumap: Synthetic events and const/static Ian Rogers
2022-06-14 14:33 ` Ian Rogers [this message]
2022-06-14 14:33 ` [PATCH v2 4/6] perf cpumap: Fix alignment for masks in event encoding Ian Rogers
2022-06-14 22:44   ` Namhyung Kim
2022-06-14 23:51     ` Ian Rogers
2022-06-29  9:18   ` Jiri Olsa
2022-06-29 16:05     ` Ian Rogers
2022-08-18 21:50   ` Arnaldo Carvalho de Melo
2022-08-18 22:49     ` Ian Rogers
2022-08-19 15:58     ` Arnaldo Carvalho de Melo
2022-08-19 17:09       ` Ian Rogers
2022-08-19 17:28         ` Arnaldo Carvalho de Melo
2022-08-26 12:57   ` Alexander Gordeev
2022-08-26 16:20     ` Ian Rogers
2022-06-14 14:33 ` [PATCH v2 5/6] perf events: Prefer union over variable length array Ian Rogers
2022-06-14 14:33 ` [PATCH v2 6/6] perf cpumap: Add range data encoding Ian Rogers
2022-06-29  9:31   ` Jiri Olsa
2022-06-29 16:19     ` Ian Rogers
2022-07-31 12:39   ` Jiri Olsa
2022-08-04 19:30     ` Ian Rogers
2022-09-07 22:41       ` Ian Rogers
2022-09-07 23:47         ` Arnaldo Carvalho de Melo
2022-09-08 18:52         ` Arnaldo Carvalho de Melo
2022-07-15 17:01 ` [PATCH v2 0/6] Corrections to cpu map event encoding Ian Rogers
2022-07-29  2:01   ` Ian Rogers
2022-07-29 11:35     ` Jiri Olsa
2022-07-29 14:28       ` Ian Rogers
2022-07-31 12:37         ` Jiri Olsa
2022-08-04 20:23 ` Jiri Olsa
     [not found]   ` <CAP-5=fX-Ex1uv0hxCwDkkAyFV6VQNPRB5uSPpCDNgqu5ZV=bCA@mail.gmail.com>
2022-08-16 19:51     ` Arnaldo Carvalho de Melo

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