In __decay_sum(), the 64-bit to 32-bit variable conversion makes no performance nor correctness use.
Minor cleanup and no functionality change. Signed-off-by: Yuyang Du <[email protected]> --- kernel/sched/fair.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 283e2c2..eea3349 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2616,16 +2616,11 @@ static const u32 __accumulated_sum_N32[] = { */ static __always_inline u64 __decay_sum(u64 val, u64 n) { - unsigned int local_n; - if (!n) return val; else if (unlikely(n > SCHED_AVG_HALFLIFE * 63)) return 0; - /* after bounds checking we can collapse to 32-bit */ - local_n = n; - /* * As y^HALFLIFE = 1/2, we can combine * y^n = 1/2^(n/HALFLIFE) * y^(n%HALFLIFE) @@ -2633,12 +2628,12 @@ static __always_inline u64 __decay_sum(u64 val, u64 n) * * To achieve constant time __decay_load. */ - if (unlikely(local_n >= SCHED_AVG_HALFLIFE)) { - val >>= local_n / SCHED_AVG_HALFLIFE; - local_n %= SCHED_AVG_HALFLIFE; + if (unlikely(n >= SCHED_AVG_HALFLIFE)) { + val >>= n / SCHED_AVG_HALFLIFE; + n %= SCHED_AVG_HALFLIFE; } - val = mul_u64_u32_shr(val, __decay_inv_multiply_N[local_n], 32); + val = mul_u64_u32_shr(val, __decay_inv_multiply_N[n], 32); return val; } -- 1.7.9.5
