diff options
author | Dietmar Eggemann <dietmar.eggemann@arm.com> | 2022-07-29 13:13:05 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2022-08-02 12:32:46 +0200 |
commit | b3f53daacc74c0ca0922e14a8cb793cb2db4c6d1 (patch) | |
tree | 558a374df2d3b76746ee6a6cd6ec0e8ff14723e6 /kernel/sched/sched.h | |
parent | sched/deadline: Make dl_cpuset_cpumask_can_shrink() capacity-aware (diff) | |
download | linux-dev-b3f53daacc74c0ca0922e14a8cb793cb2db4c6d1.tar.xz linux-dev-b3f53daacc74c0ca0922e14a8cb793cb2db4c6d1.zip |
sched/deadline: Use sched_dl_entity's dl_density in dl_task_fits_capacity()
Save a multiplication in dl_task_fits_capacity() by using already
maintained per-sched_dl_entity (i.e. per-task) `dl_runtime/dl_deadline`
(dl_density).
cap_scale(dl_deadline, cap) >= dl_runtime
dl_deadline * cap >> SCHED_CAPACITY_SHIFT >= dl_runtime
cap >= dl_runtime << SCHED_CAPACITY_SHIFT / dl_deadline
cap >= (dl_runtime << BW_SHIFT / dl_deadline) >>
BW_SHIFT - SCHED_CAPACITY_SHIFT
cap >= dl_density >> BW_SHIFT - SCHED_CAPACITY_SHIFT
__sched_setscheduler()->__checkparam_dl() ensures that the 2 corner
cases (if conditions) `runtime == RUNTIME_INF (-1)` and `period == 0`
of to_ratio(deadline, runtime) are not met when setting dl_density in
__sched_setscheduler()-> __setscheduler_params()->__setparam_dl().
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20220729111305.1275158-4-dietmar.eggemann@arm.com
Diffstat (limited to 'kernel/sched/sched.h')
-rw-r--r-- | kernel/sched/sched.h | 30 |
1 files changed, 15 insertions, 15 deletions
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 86fc36069f38..3ccd35c22f0f 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -320,21 +320,6 @@ struct dl_bw { u64 total_bw; }; -/* - * Verify the fitness of task @p to run on @cpu taking into account the - * CPU original capacity and the runtime/deadline ratio of the task. - * - * The function will return true if the CPU original capacity of the - * @cpu scaled by SCHED_CAPACITY_SCALE >= runtime/deadline ratio of the - * task and false otherwise. - */ -static inline bool dl_task_fits_capacity(struct task_struct *p, int cpu) -{ - unsigned long cap = arch_scale_cpu_capacity(cpu); - - return cap_scale(p->dl.dl_deadline, cap) >= p->dl.dl_runtime; -} - extern void init_dl_bw(struct dl_bw *dl_b); extern int sched_dl_global_validate(void); extern void sched_dl_do_global(void); @@ -2899,6 +2884,21 @@ unsigned long effective_cpu_util(int cpu, unsigned long util_cfs, enum cpu_util_type type, struct task_struct *p); +/* + * Verify the fitness of task @p to run on @cpu taking into account the + * CPU original capacity and the runtime/deadline ratio of the task. + * + * The function will return true if the original capacity of @cpu is + * greater than or equal to task's deadline density right shifted by + * (BW_SHIFT - SCHED_CAPACITY_SHIFT) and false otherwise. + */ +static inline bool dl_task_fits_capacity(struct task_struct *p, int cpu) +{ + unsigned long cap = arch_scale_cpu_capacity(cpu); + + return cap >= p->dl.dl_density >> (BW_SHIFT - SCHED_CAPACITY_SHIFT); +} + static inline unsigned long cpu_bw_dl(struct rq *rq) { return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT; |