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authorLinus Torvalds <torvalds@linux-foundation.org>2020-06-03 13:06:42 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-03 13:06:42 -0700
commitd479c5a1919b4e569dcd3ae9c84ed74a675d0b94 (patch)
tree99d0ad6f712b152991a5846034a184ba857beed7 /kernel/sched/rt.c
parentf6aee505c71bbb035dde146caf5a6abbf3ccbe47 (diff)
parent25de110d148666752dc0e0da7a0b69de31cd7098 (diff)
Merge tag 'sched-core-2020-06-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar: "The changes in this cycle are: - Optimize the task wakeup CPU selection logic, to improve scalability and reduce wakeup latency spikes - PELT enhancements - CFS bandwidth handling fixes - Optimize the wakeup path by remove rq->wake_list and replacing it with ->ttwu_pending - Optimize IPI cross-calls by making flush_smp_call_function_queue() process sync callbacks first. - Misc fixes and enhancements" * tag 'sched-core-2020-06-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) irq_work: Define irq_work_single() on !CONFIG_IRQ_WORK too sched/headers: Split out open-coded prototypes into kernel/sched/smp.h sched: Replace rq::wake_list sched: Add rq::ttwu_pending irq_work, smp: Allow irq_work on call_single_queue smp: Optimize send_call_function_single_ipi() smp: Move irq_work_run() out of flush_smp_call_function_queue() smp: Optimize flush_smp_call_function_queue() sched: Fix smp_call_function_single_async() usage for ILB sched/core: Offload wakee task activation if it the wakee is descheduling sched/core: Optimize ttwu() spinning on p->on_cpu sched: Defend cfs and rt bandwidth quota against overflow sched/cpuacct: Fix charge cpuacct.usage_sys sched/fair: Replace zero-length array with flexible-array sched/pelt: Sync util/runnable_sum with PELT window when propagating sched/cpuacct: Use __this_cpu_add() instead of this_cpu_ptr() sched/fair: Optimize enqueue_task_fair() sched: Make scheduler_ipi inline sched: Clean up scheduler_ipi() sched/core: Simplify sched_init() ...
Diffstat (limited to 'kernel/sched/rt.c')
-rw-r--r--kernel/sched/rt.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index df11d88c9895..6d60ba21ed29 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -9,6 +9,8 @@
int sched_rr_timeslice = RR_TIMESLICE;
int sysctl_sched_rr_timeslice = (MSEC_PER_SEC / HZ) * RR_TIMESLICE;
+/* More than 4 hours if BW_SHIFT equals 20. */
+static const u64 max_rt_runtime = MAX_BW;
static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun);
@@ -2585,6 +2587,12 @@ static int tg_set_rt_bandwidth(struct task_group *tg,
if (rt_period == 0)
return -EINVAL;
+ /*
+ * Bound quota to defend quota against overflow during bandwidth shift.
+ */
+ if (rt_runtime != RUNTIME_INF && rt_runtime > max_rt_runtime)
+ return -EINVAL;
+
mutex_lock(&rt_constraints_mutex);
err = __rt_schedulable(tg, rt_period, rt_runtime);
if (err)
@@ -2702,7 +2710,9 @@ static int sched_rt_global_validate(void)
return -EINVAL;
if ((sysctl_sched_rt_runtime != RUNTIME_INF) &&
- (sysctl_sched_rt_runtime > sysctl_sched_rt_period))
+ ((sysctl_sched_rt_runtime > sysctl_sched_rt_period) ||
+ ((u64)sysctl_sched_rt_runtime *
+ NSEC_PER_USEC > max_rt_runtime)))
return -EINVAL;
return 0;