@@ -1008,7 +1008,8 @@ static void update_curr_dl(struct rq *rq)
{
struct task_struct *curr = rq->curr;
struct sched_dl_entity *dl_se = &curr->dl;
- u64 delta_exec;
+ u64 delta_exec, scaled_delta_exec;
+ int cpu = cpu_of(rq);
if (!dl_task(curr) || !on_dl_rq(dl_se))
return;
@@ -1042,9 +1043,26 @@ static void update_curr_dl(struct rq *rq)
if (unlikely(dl_entity_is_special(dl_se)))
return;
- if (unlikely(dl_se->flags & SCHED_FLAG_RECLAIM))
- delta_exec = grub_reclaim(delta_exec, rq, &curr->dl);
- dl_se->runtime -= delta_exec;
+ /*
+ * For tasks that participate in GRUB, we implement GRUB-PA: the
+ * spare reclaimed bandwidth is used to clock down frequency.
+ *
+ * For the others, we still need to scale reservation parameters
+ * according to current frequency and CPU maximum capacity.
+ */
+ if (unlikely(dl_se->flags & SCHED_FLAG_RECLAIM)) {
+ scaled_delta_exec = grub_reclaim(delta_exec,
+ rq,
+ &curr->dl);
+ } else {
+ unsigned long scale_freq = arch_scale_freq_capacity(cpu);
+ unsigned long scale_cpu = arch_scale_cpu_capacity(NULL, cpu);
+
+ scaled_delta_exec = cap_scale(delta_exec, scale_freq);
+ scaled_delta_exec = cap_scale(scaled_delta_exec, scale_cpu);
+ }
+
+ dl_se->runtime -= scaled_delta_exec;
throttle:
if (dl_runtime_exceeded(dl_se) || dl_se->dl_yielded) {
@@ -2781,8 +2781,6 @@ static u32 __accumulate_pelt_segments(u64 periods, u32 d1, u32 d3)
return c1 + c2 + c3;
}
-#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT)
-
/*
* Accumulate the three separate parts of the sum; d1 the remainder
* of the last (incomplete) period, d2 the span of full periods and d3
@@ -155,6 +155,8 @@ static inline int task_has_dl_policy(struct task_struct *p)
return dl_policy(p->policy);
}
+#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT)
+
static inline int dl_entity_is_special(struct sched_dl_entity *dl_se)
{
return dl_se->flags & SCHED_FLAG_SPECIAL;
Apply frequency and cpu scale-invariance correction factor to bandwidth enforcement (similar to what we already do to fair utilization tracking). Each delta_exec gets scaled considering current frequency and maximum cpu capacity; which means that the reservation runtime parameter (that need to be specified profiling the task execution at max frequency on biggest capacity core) gets thus scaled accordingly. Signed-off-by: Juri Lelli <juri.lelli@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Claudio Scordino <claudio@evidence.eu.com> --- Changes from RFD - either apply grub_reclaim or perform freq/cpu scaling; what's the correct thing to do it's actually very much up for discussion --- kernel/sched/deadline.c | 26 ++++++++++++++++++++++---- kernel/sched/fair.c | 2 -- kernel/sched/sched.h | 2 ++ 3 files changed, 24 insertions(+), 6 deletions(-) -- 2.11.0