Messages in this thread Patch in this message | | | From | Afzal Mohammed <> | Subject | [PATCH] sched,fair: Remove > u32 weight handling for delta | Date | Mon, 6 Jul 2015 08:14:37 +0530 |
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scaled down weight 'fact' would not be > u32 rather than unlikely as the values being passed for delta is either NICE_O_LOAD or the weight of the 'se' which would be a value that can be accomodated in a u32. Remove the initial > u32 handling on 'fact'.
9dbdb15553239 ("sched/fair: Rework sched_fair time accounting") in addition to fixing the original issue of time moving backwards elsewhere in the code, handled delta > u32 case (due to NO_HZ_FULL) which brought in as it's part the change changed here. The hunk being removed here would not make a difference to it as this is on scaled weight > u32. And pre-"9dbdb15553239" doesn't seem to have logical equivalent of hunk removed here either.
Signed-off-by: Afzal Mohammed <afzal.mohd.ma@gmail.com> --- System here (that mainly does kernel build) has been running with this change for last couple of weeks without any issue observed. kernel/sched/fair.c | 7 ------- 1 file changed, 7 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 3d57cc0ca0a6..0cc58a7bdd16 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -218,13 +218,6 @@ static u64 __calc_delta(u64 delta_exec, unsigned long weight, struct load_weight __update_inv_weight(lw); - if (unlikely(fact >> 32)) { - while (fact >> 32) { - fact >>= 1; - shift--; - } - } - /* hint to use a 32x32->64 mul */ fact = (u64)(u32)fact * lw->inv_weight; -- 2.1.4
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