From: Jules Irenge <jbi.octave@gmail.com>
To: mark.rutland@arm.com
Cc: alexander.shishkin@linux.intel.com, jolsa@kernel.org,
irogers@google.com, adrian.hunter@intel.com, bp@alien8.de,
dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] perf/x86/amd/power: Use div64_u64 onstead of do_div()
Date: Sun, 28 Apr 2024 17:40:25 +0100 [thread overview]
Message-ID: <Zi57-TMgU19puaQM@octinomon.home> (raw)
do_div() truncates a u64 divisor to 32 bit.
This can lead to non-zero being truncated to zero for division.
Fix coccinelle warning
WARNING: do_div() does a 64-by-32 division, please consider using div64_u64 instead
Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
---
arch/x86/events/amd/power.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/events/amd/power.c b/arch/x86/events/amd/power.c
index 37d5b380516e..ff003c1a645b 100644
--- a/arch/x86/events/amd/power.c
+++ b/arch/x86/events/amd/power.c
@@ -64,7 +64,7 @@ static void event_update(struct perf_event *event)
delta *= cpu_pwr_sample_ratio * 1000;
tdelta = new_ptsc - prev_ptsc;
- do_div(delta, tdelta);
+ div64_u64(delta, tdelta);
local64_add(delta, &event->count);
}
--
2.43.2
next reply other threads:[~2024-04-28 16:40 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-28 16:40 Jules Irenge [this message]
2024-05-02 16:25 ` [PATCH] perf/x86/amd/power: Use div64_u64 onstead of do_div() David Laight
2024-05-02 16:34 ` Jules Bashizi Irenge
2024-05-02 22:18 ` David Laight
2024-05-02 22:59 ` Linus Torvalds
2024-05-04 22:53 ` David Laight
2024-05-05 19:38 ` Linus Torvalds
2024-05-06 16:39 ` David Laight
2024-05-06 16:45 ` Linus Torvalds
2024-05-06 17:26 ` Linus Torvalds
2024-05-06 20:25 ` David Laight
2024-05-06 17:43 ` David Laight
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