Messages in this thread Patch in this message | | | From | Thomas Gleixner <> | Subject | timers: Simplify calc_index() | Date | Mon, 04 Apr 2022 16:47:55 +0200 |
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The level granularity round up of calc_index() does:
(x + (1 << n)) >> n
which is obviously equivalent to
(x >> n) + 1
but compilers can't figure that out despite the fact that the input range is known to not cause an overflow. It's neither intuitive to read.
Just write out the obvious.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- kernel/time/timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -502,7 +502,7 @@ static inline unsigned calc_index(unsign * * Round up with level granularity to prevent this. */ - expires = (expires + LVL_GRAN(lvl)) >> LVL_SHIFT(lvl); + expires = (expires >> LVL_SHIFT(lvl)) + 1; *bucket_expiry = expires << LVL_SHIFT(lvl); return LVL_OFFS(lvl) + (expires & LVL_MASK); }
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