diff options
Diffstat (limited to 'kernel/sched/deadline.c')
| -rw-r--r-- | kernel/sched/deadline.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 0bee537554f6..6a0614b9c8d7 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -268,6 +268,7 @@ void init_dl_rq(struct dl_rq *dl_rq) #endif dl_rq->running_bw = 0; + init_dl_rq_bw_ratio(dl_rq); } #ifdef CONFIG_SMP @@ -924,11 +925,20 @@ extern bool sched_rt_bandwidth_account(struct rt_rq *rt_rq); * Uact is the (per-runqueue) active utilization. * Since rq->dl.running_bw contains Uact * 2^BW_SHIFT, the result * has to be shifted right by BW_SHIFT. + * To reclaim only a fraction Umax of the CPU time, the + * runtime accounting rule is modified as + * "dq = -Uact / Umax dt"; since rq->dl.bw_ratio contains + * 2^RATIO_SHIFT / Umax, delta is multiplied by bw_ratio and shifted + * right by RATIO_SHIFT. + * Since delta is a 64 bit variable, to have an overflow its value + * should be larger than 2^(64 - 20 - 8), which is more than 64 seconds. + * So, overflow is not an issue here. */ u64 grub_reclaim(u64 delta, struct rq *rq) { delta *= rq->dl.running_bw; - delta >>= BW_SHIFT; + delta *= rq->dl.bw_ratio; + delta >>= BW_SHIFT + RATIO_SHIFT; return delta; } |