linux-kernel - [PATCH 06/49] nds32: perf: replace bitmap_weight with bitmap

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Date:   Thu, 10 Feb 2022 14:48:50 -0800
From:   Yury Norov <yury.norov@...il.com>
To:     Yury Norov <yury.norov@...il.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Rasmus Villemoes <linux@...musvillemoes.dk>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Michał Mirosław <mirq-linux@...e.qmqm.pl>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Peter Zijlstra <peterz@...radead.org>,
        David Laight <David.Laight@...lab.com>,
        Joe Perches <joe@...ches.com>, Dennis Zhou <dennis@...nel.org>,
        Emil Renner Berthing <kernel@...il.dk>,
        Nicholas Piggin <npiggin@...il.com>,
        Matti Vaittinen <matti.vaittinen@...rohmeurope.com>,
        Alexey Klimov <aklimov@...hat.com>,
        linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...hat.com>,
        Namhyung Kim <namhyung@...nel.org>,
        Nick Hu <nickhu@...estech.com>,
        Greentime Hu <green.hu@...il.com>,
        Vincent Chen <deanbo422@...il.com>,
        linux-perf-users@...r.kernel.org
Subject: [PATCH 06/49] nds32: perf: replace bitmap_weight with bitmap_empty where appropriate

nds32_pmu_enable calls bitmap_weight() to check if any bit of a given
bitmap is set. It's better to use bitmap_empty() in that case because
bitmap_empty() stops traversing the bitmap as soon as it finds first
set bit, while bitmap_weight() counts all bits unconditionally.

Signed-off-by: Yury Norov <yury.norov@...il.com>
---
 arch/nds32/kernel/perf_event_cpu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/nds32/kernel/perf_event_cpu.c b/arch/nds32/kernel/perf_event_cpu.c
index a78a879e7ef1..ea44e9ecb5c7 100644
--- a/arch/nds32/kernel/perf_event_cpu.c
+++ b/arch/nds32/kernel/perf_event_cpu.c
@@ -695,7 +695,7 @@ static void nds32_pmu_enable(struct pmu *pmu)
 {
 	struct nds32_pmu *nds32_pmu = to_nds32_pmu(pmu);
 	struct pmu_hw_events *hw_events = nds32_pmu->get_hw_events();
-	int enabled = bitmap_weight(hw_events->used_mask,
+	bool enabled = !bitmap_empty(hw_events->used_mask,
 				    nds32_pmu->num_events);
 
 	if (enabled)
-- 
2.32.0