In current code, decay_load() will consider to set load value to zero
after passing 32*64 ms. So this means max_load * (0.5^64) ~= 0.
Kernel can support maximum number of processes and threads to 2^29 and
set task with highest priority with nice=-20 (weight = 88761). So in
worst case, one CPU may have maximum load value is:
max_load = 2^29 * 88761 < 2^46
In theory after pass 46 periods we can ensure load value will be decayed
to zero. So this patch is to change maximum periods from 64 to 48.
Signed-off-by: Leo Yan <leo....@linaro.org>
---
kernel/sched/fair.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e342159..55cb134 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2622,7 +2622,7 @@ static __always_inline u64 decay_load(u64 val, u64 n)
if (!n)
return val;
- else if (unlikely(n > LOAD_AVG_PERIOD * 63))
+ else if (unlikely(n > LOAD_AVG_PERIOD * 47))
return 0;
/* after bounds checking we can collapse to 32-bit */
--
1.9.1
