sched_fair: vruntime and min_vruntime will be overflow?

sched_fair: vruntime and min_vruntime will be overflow?

[figo zhang]

hi,

when enqueue or dequeue the task, the se->vruntime and cfs_rq->min_vruntime will
increased, i want to know it is will be overflow in future time?

Best,
Figo.zhang

Re: sched_fair: vruntime and min_vruntime will be overflow?

[KOSAKI Motohiro]

> hi,
> 
> when enqueue or dequeue the task, the se->vruntime and cfs_rq->min_vruntime will
> increased, i want to know it is will be overflow in future time?

Let's quick calculation.

type of vruntime is u64.
 
1 year =   365 x 24 x 60 x 60 x 1000 x 1000 x 1000 nanosec
           ~= 3 x 10^16
           ~= 2^55
2^64 / 2^55 = 2^9 ~= 500 year.

then, 500 years after you can see overflow if you still live. :)