lkml.org 
[lkml]   [2015]   [Jul]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] sched,fair: Remove > u32 weight handling for delta
Date
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


\
 
 \ /
  Last update: 2015-07-06 05:01    [W:1.666 / U:0.316 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site