lkml.org 
[lkml]   [2020]   [Jan]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] timekeeping: improve arithmetic divisions
Date
do_div() does a 64-by-32 division. Use div64_u64()
instead of do_div() if the divisor is u64,
to avoid truncation to 32-bit.

Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-kernel@vger.kernel.org
---
kernel/time/timekeeping.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index ca69290..bad76c1 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1007,7 +1007,7 @@ static int scale64_check_overflow(u64 mult, u64 div, u64 *base)
tmp *= mult;
rem *= mult;

- do_div(rem, div);
+ rem = div64_u64(rem, div);
*base = tmp + rem;
return 0;
}
--
1.8.3.1
\
 
 \ /
  Last update: 2020-01-03 16:56    [W:0.032 / U:14.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site