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authorLinus Torvalds <torvalds@linux-foundation.org>2021-02-21 12:35:04 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-02-21 12:35:04 -0800
commit657bd90c93146a929c69cd43addf2804eb70c926 (patch)
treee643825c87070f83df58d37d4daf0417eb17e8c2 /kernel
parent7b15c27e2f7b6d114770c2922b2c49d2e8f3867c (diff)
parentc5e6fc08feb2b88dc5dac2f3c817e1c2a4cafda4 (diff)
downloadlinux-657bd90c93146a929c69cd43addf2804eb70c926.tar.gz
Merge tag 'sched-core-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar: "Core scheduler updates: - Add CONFIG_PREEMPT_DYNAMIC: this in its current form adds the preempt=none/voluntary/full boot options (default: full), to allow distros to build a PREEMPT kernel but fall back to close to PREEMPT_VOLUNTARY (or PREEMPT_NONE) runtime scheduling behavior via a boot time selection. There's also the /debug/sched_debug switch to do this runtime. This feature is implemented via runtime patching (a new variant of static calls). The scope of the runtime patching can be best reviewed by looking at the sched_dynamic_update() function in kernel/sched/core.c. ( Note that the dynamic none/voluntary mode isn't 100% identical, for example preempt-RCU is available in all cases, plus the preempt count is maintained in all models, which has runtime overhead even with the code patching. ) The PREEMPT_VOLUNTARY/PREEMPT_NONE models, used by the vast majority of distributions, are supposed to be unaffected. - Fix ignored rescheduling after rcu_eqs_enter(). This is a bug that was found via rcutorture triggering a hang. The bug is that rcu_idle_enter() may wake up a NOCB kthread, but this happens after the last generic need_resched() check. Some cpuidle drivers fix it by chance but many others don't. In true 2020 fashion the original bug fix has grown into a 5-patch scheduler/RCU fix series plus another 16 RCU patches to address the underlying issue of missed preemption events. These are the initial fixes that should fix current incarnations of the bug. - Clean up rbtree usage in the scheduler, by providing & using the following consistent set of rbtree APIs: partial-order; less() based: - rb_add(): add a new entry to the rbtree - rb_add_cached(): like rb_add(), but for a rb_root_cached total-order; cmp() based: - rb_find(): find an entry in an rbtree - rb_find_add(): find an entry, and add if not found - rb_find_first(): find the first (leftmost) matching entry - rb_next_match(): continue from rb_find_first() - rb_for_each(): iterate a sub-tree using the previous two - Improve the SMP/NUMA load-balancer: scan for an idle sibling in a single pass. This is a 4-commit series where each commit improves one aspect of the idle sibling scan logic. - Improve the cpufreq cooling driver by getting the effective CPU utilization metrics from the scheduler - Improve the fair scheduler's active load-balancing logic by reducing the number of active LB attempts & lengthen the load-balancing interval. This improves stress-ng mmapfork performance. - Fix CFS's estimated utilization (util_est) calculation bug that can result in too high utilization values Misc updates & fixes: - Fix the HRTICK reprogramming & optimization feature - Fix SCHED_SOFTIRQ raising race & warning in the CPU offlining code - Reduce dl_add_task_root_domain() overhead - Fix uprobes refcount bug - Process pending softirqs in flush_smp_call_function_from_idle() - Clean up task priority related defines, remove *USER_*PRIO and USER_PRIO() - Simplify the sched_init_numa() deduplication sort - Documentation updates - Fix EAS bug in update_misfit_status(), which degraded the quality of energy-balancing - Smaller cleanups" * tag 'sched-core-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits) sched,x86: Allow !PREEMPT_DYNAMIC entry/kvm: Explicitly flush pending rcuog wakeup before last rescheduling point entry: Explicitly flush pending rcuog wakeup before last rescheduling point rcu/nocb: Trigger self-IPI on late deferred wake up before user resume rcu/nocb: Perform deferred wake up before last idle's need_resched() check rcu: Pull deferred rcuog wake up to rcu_eqs_enter() callers sched/features: Distinguish between NORMAL and DEADLINE hrtick sched/features: Fix hrtick reprogramming sched/deadline: Reduce rq lock contention in dl_add_task_root_domain() uprobes: (Re)add missing get_uprobe() in __find_uprobe() smp: Process pending softirqs in flush_smp_call_function_from_idle() sched: Harden PREEMPT_DYNAMIC static_call: Allow module use without exposing static_call_key sched: Add /debug/sched_preempt preempt/dynamic: Support dynamic preempt with preempt= boot option preempt/dynamic: Provide irqentry_exit_cond_resched() static call preempt/dynamic: Provide preempt_schedule[_notrace]() static calls preempt/dynamic: Provide cond_resched() and might_resched() static calls preempt: Introduce CONFIG_PREEMPT_DYNAMIC static_call: Provide DEFINE_STATIC_CALL_RET0() ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/Kconfig.preempt19
-rw-r--r--kernel/entry/common.c17
-rw-r--r--kernel/events/core.c195
-rw-r--r--kernel/events/uprobes.c80
-rw-r--r--kernel/locking/rtmutex.c54
-rw-r--r--kernel/rcu/tree.c53
-rw-r--r--kernel/rcu/tree.h2
-rw-r--r--kernel/rcu/tree_plugin.h31
-rw-r--r--kernel/sched/core.c357
-rw-r--r--kernel/sched/cpufreq_schedutil.c108
-rw-r--r--kernel/sched/deadline.c94
-rw-r--r--kernel/sched/debug.c2
-rw-r--r--kernel/sched/fair.c322
-rw-r--r--kernel/sched/features.h2
-rw-r--r--kernel/sched/idle.c1
-rw-r--r--kernel/sched/rt.c2
-rw-r--r--kernel/sched/sched.h51
-rw-r--r--kernel/sched/topology.c99
-rw-r--r--kernel/smp.c4
-rw-r--r--kernel/static_call.c60
20 files changed, 941 insertions, 612 deletions
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index bf82259cff96..416017301660 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -40,6 +40,7 @@ config PREEMPT
depends on !ARCH_NO_PREEMPT
select PREEMPTION
select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK
+ select PREEMPT_DYNAMIC if HAVE_PREEMPT_DYNAMIC
help
This option reduces the latency of the kernel by making
all kernel code (that is not executing in a critical section)
@@ -80,3 +81,21 @@ config PREEMPT_COUNT
config PREEMPTION
bool
select PREEMPT_COUNT
+
+config PREEMPT_DYNAMIC
+ bool
+ help
+ This option allows to define the preemption model on the kernel
+ command line parameter and thus override the default preemption
+ model defined during compile time.
+
+ The feature is primarily interesting for Linux distributions which
+ provide a pre-built kernel binary to reduce the number of kernel
+ flavors they offer while still offering different usecases.
+
+ The runtime overhead is negligible with HAVE_STATIC_CALL_INLINE enabled
+ but if runtime patching is not available for the specific architecture
+ then the potential overhead should be considered.
+
+ Interesting if you want the same pre-built kernel should be used for
+ both Server and Desktop workloads.
diff --git a/kernel/entry/common.c b/kernel/entry/common.c
index f9d491b17b78..8442e5c9cfa2 100644
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -184,6 +184,10 @@ static unsigned long exit_to_user_mode_loop(struct pt_regs *regs,
* enabled above.
*/
local_irq_disable_exit_to_user();
+
+ /* Check if any of the above work has queued a deferred wakeup */
+ rcu_nocb_flush_deferred_wakeup();
+
ti_work = READ_ONCE(current_thread_info()->flags);
}
@@ -197,6 +201,9 @@ static void exit_to_user_mode_prepare(struct pt_regs *regs)
lockdep_assert_irqs_disabled();
+ /* Flush pending rcuog wakeup before the last need_resched() check */
+ rcu_nocb_flush_deferred_wakeup();
+
if (unlikely(ti_work & EXIT_TO_USER_MODE_WORK))
ti_work = exit_to_user_mode_loop(regs, ti_work);
@@ -385,6 +392,9 @@ void irqentry_exit_cond_resched(void)
preempt_schedule_irq();
}
}
+#ifdef CONFIG_PREEMPT_DYNAMIC
+DEFINE_STATIC_CALL(irqentry_exit_cond_resched, irqentry_exit_cond_resched);
+#endif
noinstr void irqentry_exit(struct pt_regs *regs, irqentry_state_t state)
{
@@ -411,8 +421,13 @@ noinstr void irqentry_exit(struct pt_regs *regs, irqentry_state_t state)
}
instrumentation_begin();
- if (IS_ENABLED(CONFIG_PREEMPTION))
+ if (IS_ENABLED(CONFIG_PREEMPTION)) {
+#ifdef CONFIG_PREEMT_DYNAMIC
+ static_call(irqentry_exit_cond_resched)();
+#else
irqentry_exit_cond_resched();
+#endif
+ }
/* Covers both tracing and lockdep */
trace_hardirqs_on();
instrumentation_end();
diff --git a/kernel/events/core.c b/kernel/events/core.c
index c37401e3e5f7..5fe7d6346762 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1597,50 +1597,91 @@ static void perf_event_groups_init(struct perf_event_groups *groups)
groups->index = 0;
}
+static inline struct cgroup *event_cgroup(const struct perf_event *event)
+{
+ struct cgroup *cgroup = NULL;
+
+#ifdef CONFIG_CGROUP_PERF
+ if (event->cgrp)
+ cgroup = event->cgrp->css.cgroup;
+#endif
+
+ return cgroup;
+}
+
/*
* Compare function for event groups;
*
* Implements complex key that first sorts by CPU and then by virtual index
* which provides ordering when rotating groups for the same CPU.
*/
-static bool
-perf_event_groups_less(struct perf_event *left, struct perf_event *right)
+static __always_inline int
+perf_event_groups_cmp(const int left_cpu, const struct cgroup *left_cgroup,
+ const u64 left_group_index, const struct perf_event *right)
{
- if (left->cpu < right->cpu)
- return true;
- if (left->cpu > right->cpu)
- return false;
+ if (left_cpu < right->cpu)
+ return -1;
+ if (left_cpu > right->cpu)
+ return 1;
#ifdef CONFIG_CGROUP_PERF
- if (left->cgrp != right->cgrp) {
- if (!left->cgrp || !left->cgrp->css.cgroup) {
- /*
- * Left has no cgroup but right does, no cgroups come
- * first.
- */
- return true;
- }
- if (!right->cgrp || !right->cgrp->css.cgroup) {
- /*
- * Right has no cgroup but left does, no cgroups come
- * first.
- */
- return false;
- }
- /* Two dissimilar cgroups, order by id. */
- if (left->cgrp->css.cgroup->kn->id < right->cgrp->css.cgroup->kn->id)
- return true;
+ {
+ const struct cgroup *right_cgroup = event_cgroup(right);
- return false;
+ if (left_cgroup != right_cgroup) {
+ if (!left_cgroup) {
+ /*
+ * Left has no cgroup but right does, no
+ * cgroups come first.
+ */
+ return -1;
+ }
+ if (!right_cgroup) {
+ /*
+ * Right has no cgroup but left does, no
+ * cgroups come first.
+ */
+ return 1;
+ }
+ /* Two dissimilar cgroups, order by id. */
+ if (cgroup_id(left_cgroup) < cgroup_id(right_cgroup))
+ return -1;
+
+ return 1;
+ }
}
#endif
- if (left->group_index < right->group_index)
- return true;
- if (left->group_index > right->group_index)
- return false;
+ if (left_group_index < right->group_index)
+ return -1;
+ if (left_group_index > right->group_index)
+ return 1;
- return false;
+ return 0;
+}
+
+#define __node_2_pe(node) \
+ rb_entry((node), struct perf_event, group_node)
+
+static inline bool __group_less(struct rb_node *a, const struct rb_node *b)
+{
+ struct perf_event *e = __node_2_pe(a);
+ return perf_event_groups_cmp(e->cpu, event_cgroup(e), e->group_index,
+ __node_2_pe(b)) < 0;
+}
+
+struct __group_key {
+ int cpu;
+ struct cgroup *cgroup;
+};
+
+static inline int __group_cmp(const void *key, const struct rb_node *node)
+{
+ const struct __group_key *a = key;
+ const struct perf_event *b = __node_2_pe(node);
+
+ /* partial/subtree match: @cpu, @cgroup; ignore: @group_index */
+ return perf_event_groups_cmp(a->cpu, a->cgroup, b->group_index, b);
}
/*
@@ -1652,27 +1693,9 @@ static void
perf_event_groups_insert(struct perf_event_groups *groups,
struct perf_event *event)
{
- struct perf_event *node_event;
- struct rb_node *parent;
- struct rb_node **node;
-
event->group_index = ++groups->index;
- node = &groups->tree.rb_node;
- parent = *node;
-
- while (*node) {
- parent = *node;
- node_event = container_of(*node, struct perf_event, group_node);
-
- if (perf_event_groups_less(event, node_event))
- node = &parent->rb_left;
- else
- node = &parent->rb_right;
- }
-
- rb_link_node(&event->group_node, parent, node);
- rb_insert_color(&event->group_node, &groups->tree);
+ rb_add(&event->group_node, &groups->tree, __group_less);
}
/*
@@ -1720,45 +1743,17 @@ static struct perf_event *
perf_event_groups_first(struct perf_event_groups *groups, int cpu,
struct cgroup *cgrp)
{
- struct perf_event *node_event = NULL, *match = NULL;
- struct rb_node *node = groups->tree.rb_node;
-#ifdef CONFIG_CGROUP_PERF
- u64 node_cgrp_id, cgrp_id = 0;
-
- if (cgrp)
- cgrp_id = cgrp->kn->id;
-#endif
-
- while (node) {
- node_event = container_of(node, struct perf_event, group_node);
-
- if (cpu < node_event->cpu) {
- node = node->rb_left;
- continue;
- }
- if (cpu > node_event->cpu) {
- node = node->rb_right;
- continue;
- }
-#ifdef CONFIG_CGROUP_PERF
- node_cgrp_id = 0;
- if (node_event->cgrp && node_event->cgrp->css.cgroup)
- node_cgrp_id = node_event->cgrp->css.cgroup->kn->id;
+ struct __group_key key = {
+ .cpu = cpu,
+ .cgroup = cgrp,
+ };
+ struct rb_node *node;
- if (cgrp_id < node_cgrp_id) {
- node = node->rb_left;
- continue;
- }
- if (cgrp_id > node_cgrp_id) {
- node = node->rb_right;
- continue;
- }
-#endif
- match = node_event;
- node = node->rb_left;
- }
+ node = rb_find_first(&key, &groups->tree, __group_cmp);
+ if (node)
+ return __node_2_pe(node);
- return match;
+ return NULL;
}
/*
@@ -1767,27 +1762,17 @@ perf_event_groups_first(struct perf_event_groups *groups, int cpu,
static struct perf_event *
perf_event_groups_next(struct perf_event *event)
{
- struct perf_event *next;
-#ifdef CONFIG_CGROUP_PERF
- u64 curr_cgrp_id = 0;
- u64 next_cgrp_id = 0;
-#endif
-
- next = rb_entry_safe(rb_next(&event->group_node), typeof(*event), group_node);
- if (next == NULL || next->cpu != event->cpu)
- return NULL;
-
-#ifdef CONFIG_CGROUP_PERF
- if (event->cgrp && event->cgrp->css.cgroup)
- curr_cgrp_id = event->cgrp->css.cgroup->kn->id;
+ struct __group_key key = {
+ .cpu = event->cpu,
+ .cgroup = event_cgroup(event),
+ };
+ struct rb_node *next;
- if (next->cgrp && next->cgrp->css.cgroup)
- next_cgrp_id = next->cgrp->css.cgroup->kn->id;
+ next = rb_next_match(&key, &event->group_node, __group_cmp);
+ if (next)
+ return __node_2_pe(next);
- if (curr_cgrp_id != next_cgrp_id)
- return NULL;
-#endif
- return next;
+ return NULL;
}
/*
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index bf9edd8d75be..3ea7f8f92f1d 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -613,41 +613,56 @@ static void put_uprobe(struct uprobe *uprobe)
}
}
-static int match_uprobe(struct uprobe *l, struct uprobe *r)
+static __always_inline
+int uprobe_cmp(const struct inode *l_inode, const loff_t l_offset,
+ const struct uprobe *r)
{
- if (l->inode < r->inode)
+ if (l_inode < r->inode)
return -1;
- if (l->inode > r->inode)
+ if (l_inode > r->inode)
return 1;
- if (l->offset < r->offset)
+ if (l_offset < r->offset)
return -1;
- if (l->offset > r->offset)
+ if (l_offset > r->offset)
return 1;
return 0;
}
+#define __node_2_uprobe(node) \
+ rb_entry((node), struct uprobe, rb_node)
+
+struct __uprobe_key {
+ struct inode *inode;
+ loff_t offset;
+};
+
+static inline int __uprobe_cmp_key(const void *key, const struct rb_node *b)
+{
+ const struct __uprobe_key *a = key;
+ return uprobe_cmp(a->inode, a->offset, __node_2_uprobe(b));
+}
+
+static inline int __uprobe_cmp(struct rb_node *a, const struct rb_node *b)
+{
+ struct uprobe *u = __node_2_uprobe(a);
+ return uprobe_cmp(u->inode, u->offset, __node_2_uprobe(b));
+}
+
static struct uprobe *__find_uprobe(struct inode *inode, loff_t offset)
{
- struct uprobe u = { .inode = inode, .offset = offset };
- struct rb_node *n = uprobes_tree.rb_node;
- struct uprobe *uprobe;
- int match;
+ struct __uprobe_key key = {
+ .inode = inode,
+ .offset = offset,
+ };
+ struct rb_node *node = rb_find(&key, &uprobes_tree, __uprobe_cmp_key);
- while (n) {
- uprobe = rb_entry(n, struct uprobe, rb_node);
- match = match_uprobe(&u, uprobe);
- if (!match)
- return get_uprobe(uprobe);
+ if (node)
+ return get_uprobe(__node_2_uprobe(node));
- if (match < 0)
- n = n->rb_left;
- else
- n = n->rb_right;
- }
return NULL;
}
@@ -668,32 +683,15 @@ static struct uprobe *find_uprobe(struct inode *inode, loff_t offset)
static struct uprobe *__insert_uprobe(struct uprobe *uprobe)
{
- struct rb_node **p = &uprobes_tree.rb_node;
- struct rb_node *parent = NULL;
- struct uprobe *u;
- int match;
+ struct rb_node *node;
- while (*p) {
- parent = *p;
- u = rb_entry(parent, struct uprobe, rb_node);
- match = match_uprobe(uprobe, u);
- if (!match)
- return get_uprobe(u);
+ node = rb_find_add(&uprobe->rb_node, &uprobes_tree, __uprobe_cmp);
+ if (node)
+ return get_uprobe(__node_2_uprobe(node));
- if (match < 0)
- p = &parent->rb_left;
- else
- p = &parent->rb_right;
-
- }
-
- u = NULL;
- rb_link_node(&uprobe->rb_node, parent, p);
- rb_insert_color(&uprobe->rb_node, &uprobes_tree);
/* get access + creation ref */
refcount_set(&uprobe->ref, 2);
-
- return u;
+ return NULL;
}
/*
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 47a6e0b8073d..03b21135313c 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -267,27 +267,18 @@ rt_mutex_waiter_equal(struct rt_mutex_waiter *left,
return 1;
}
+#define __node_2_waiter(node) \
+ rb_entry((node), struct rt_mutex_waiter, tree_entry)
+
+static inline bool __waiter_less(struct rb_node *a, const struct rb_node *b)
+{
+ return rt_mutex_waiter_less(__node_2_waiter(a), __node_2_waiter(b));
+}
+
static void
rt_mutex_enqueue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter)
{
- struct rb_node **link = &lock->waiters.rb_root.rb_node;
- struct rb_node *parent = NULL;
- struct rt_mutex_waiter *entry;
- bool leftmost = true;
-
- while (*link) {
- parent = *link;
- entry = rb_entry(parent, struct rt_mutex_waiter, tree_entry);
- if (rt_mutex_waiter_less(waiter, entry)) {
- link = &parent->rb_left;
- } else {
- link = &parent->rb_right;
- leftmost = false;
- }
- }
-
- rb_link_node(&waiter->tree_entry, parent, link);
- rb_insert_color_cached(&waiter->tree_entry, &lock->waiters, leftmost);
+ rb_add_cached(&waiter->tree_entry, &lock->waiters, __waiter_less);
}
static void
@@ -300,27 +291,18 @@ rt_mutex_dequeue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter)
RB_CLEAR_NODE(&waiter->tree_entry);
}
+#define __node_2_pi_waiter(node) \
+ rb_entry((node), struct rt_mutex_waiter, pi_tree_entry)
+
+static inline bool __pi_waiter_less(struct rb_node *a, const struct rb_node *b)
+{
+ return rt_mutex_waiter_less(__node_2_pi_waiter(a), __node_2_pi_waiter(b));
+}
+
static void
rt_mutex_enqueue_pi(struct task_struct *task, struct rt_mutex_waiter *waiter)
{
- struct rb_node **link = &task->pi_waiters.rb_root.rb_node;
- struct rb_node *parent = NULL;
- struct rt_mutex_waiter *entry;
- bool leftmost = true;
-
- while (*link) {
- parent = *link;
- entry = rb_entry(parent, struct rt_mutex_waiter, pi_tree_entry);
- if (rt_mutex_waiter_less(waiter, entry)) {
- link = &parent->rb_left;
- } else {
- link = &parent->rb_right;
- leftmost = false;
- }
- }
-
- rb_link_node(&waiter->pi_tree_entry, parent, link);
- rb_insert_color_cached(&waiter->pi_tree_entry, &task->pi_waiters, leftmost);
+ rb_add_cached(&waiter->pi_tree_entry, &task->pi_waiters, __pi_waiter_less);
}
static void
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 0f4a6a3c057b..da6f5213fb74 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -649,7 +649,6 @@ static noinstr void rcu_eqs_enter(bool user)
trace_rcu_dyntick(TPS("Start"), rdp->dynticks_nesting, 0, atomic_read(&rdp->dynticks));
WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !user && !is_idle_task(current));
rdp = this_cpu_ptr(&rcu_data);
- do_nocb_deferred_wakeup(rdp);
rcu_prepare_for_idle();
rcu_preempt_deferred_qs(current);
@@ -683,6 +682,50 @@ void rcu_idle_enter(void)
EXPORT_SYMBOL_GPL(rcu_idle_enter);
#ifdef CONFIG_NO_HZ_FULL
+
+#if !defined(CONFIG_GENERIC_ENTRY) || !defined(CONFIG_KVM_XFER_TO_GUEST_WORK)
+/*
+ * An empty function that will trigger a reschedule on
+ * IRQ tail once IRQs get re-enabled on userspace/guest resume.
+ */
+static void late_wakeup_func(struct irq_work *work)
+{
+}
+
+static DEFINE_PER_CPU(struct irq_work, late_wakeup_work) =
+ IRQ_WORK_INIT(late_wakeup_func);
+
+/*
+ * If either:
+ *
+ * 1) the task is about to enter in guest mode and $ARCH doesn't support KVM generic work
+ * 2) the task is about to enter in user mode and $ARCH doesn't support generic entry.
+ *
+ * In these cases the late RCU wake ups aren't supported in the resched loops and our
+ * last resort is to fire a local irq_work that will trigger a reschedule once IRQs
+ * get re-enabled again.
+ */
+noinstr static void rcu_irq_work_resched(void)
+{
+ struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
+
+ if (IS_ENABLED(CONFIG_GENERIC_ENTRY) && !(current->flags & PF_VCPU))
+ return;
+
+ if (IS_ENABLED(CONFIG_KVM_XFER_TO_GUEST_WORK) && (current->flags & PF_VCPU))
+ return;
+
+ instrumentation_begin();
+ if (do_nocb_deferred_wakeup(rdp) && need_resched()) {
+ irq_work_queue(this_cpu_ptr(&late_wakeup_work));
+ }
+ instrumentation_end();
+}
+
+#else
+static inline void rcu_irq_work_resched(void) { }
+#endif
+
/**
* rcu_user_enter - inform RCU that we are resuming userspace.
*
@@ -697,8 +740,16 @@ EXPORT_SYMBOL_GPL(rcu_idle_enter);
noinstr void rcu_user_enter(void)
{
lockdep_assert_irqs_disabled();
+
+ /*
+ * Other than generic entry implementation, we may be past the last
+ * rescheduling opportunity in the entry code. Trigger a self IPI
+ * that will fire and reschedule once we resume in user/guest mode.
+ */
+ rcu_irq_work_resched();
rcu_eqs_enter(true);
}
+
#endif /* CONFIG_NO_HZ_FULL */
/**
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 5d359b9f9fec..71821d59d95c 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -435,7 +435,7 @@ static bool rcu_nocb_try_bypass(struct rcu_data *rdp, struct rcu_head *rhp,
static void __call_rcu_nocb_wake(struct rcu_data *rdp, bool was_empty,
unsigned long flags);
static int rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp);
-static void do_nocb_deferred_wakeup(struct rcu_data *rdp);
+static bool do_nocb_deferred_wakeup(struct rcu_data *rdp);
static void rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp);
static void rcu_spawn_cpu_nocb_kthread(int cpu);
static void __init rcu_spawn_nocb_kthreads(void);
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 231a0c6cf03c..2d603771c7dc 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1632,8 +1632,8 @@ bool rcu_is_nocb_cpu(int cpu)
* Kick the GP kthread for this NOCB group. Caller holds ->nocb_lock
* and this function releases it.
*/
-static void wake_nocb_gp(struct rcu_data *rdp, bool force,
- unsigned long flags)
+static bool wake_nocb_gp(struct rcu_data *rdp, bool force,
+ unsigned long flags)
__releases(rdp->nocb_lock)
{
bool needwake = false;
@@ -1644,7 +1644,7 @@ static void wake_nocb_gp(struct rcu_data *rdp, bool force,
trace_rcu_nocb_wake(rcu_state.name, rdp->cpu,
TPS("AlreadyAwake"));
rcu_nocb_unlock_irqrestore(rdp, flags);
- return;
+ return false;
}
del_timer(&rdp->nocb_timer);
rcu_nocb_unlock_irqrestore(rdp, flags);
@@ -1657,6 +1657,8 @@ static void wake_nocb_gp(struct rcu_data *rdp, bool force,
raw_spin_unlock_irqrestore(&rdp_gp->nocb_gp_lock, flags);
if (needwake)
wake_up_process(rdp_gp->nocb_gp_kthread);
+
+ return needwake;
}
/*
@@ -2251,20 +2253,23 @@ static int rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp)
}
/* Do a deferred wakeup of rcu_nocb_kthread(). */
-static void do_nocb_deferred_wakeup_common(struct rcu_data *rdp)
+static bool do_nocb_deferred_wakeup_common(struct rcu_data *rdp)
{
unsigned long flags;
int ndw;
+ int ret;
rcu_nocb_lock_irqsave(rdp, flags);
if (!rcu_nocb_need_deferred_wakeup(rdp)) {
rcu_nocb_unlock_irqrestore(rdp, flags);
- return;
+ return false;
}
ndw = READ_ONCE(rdp->nocb_defer_wakeup);
WRITE_ONCE(rdp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT);
- wake_nocb_gp(rdp, ndw == RCU_NOCB_WAKE_FORCE, flags);
+ ret = wake_nocb_gp(rdp, ndw == RCU_NOCB_WAKE_FORCE, flags);
trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("DeferredWake"));
+
+ return ret;
}
/* Do a deferred wakeup of rcu_nocb_kthread() from a timer handler. */
@@ -2280,11 +2285,18 @@ static void do_nocb_deferred_wakeup_timer(struct timer_list *t)
* This means we do an inexact common-case check. Note that if
* we miss, ->nocb_timer will eventually clean things up.
*/
-static void do_nocb_deferred_wakeup(struct rcu_data *rdp)
+static bool do_nocb_deferred_wakeup(struct rcu_data *rdp)
{
if (rcu_nocb_need_deferred_wakeup(rdp))
- do_nocb_deferred_wakeup_common(rdp);
+ return do_nocb_deferred_wakeup_common(rdp);
+ return false;
+}
+
+void rcu_nocb_flush_deferred_wakeup(void)
+{
+ do_nocb_deferred_wakeup(this_cpu_ptr(&rcu_data));
}
+EXPORT_SYMBOL_GPL(rcu_nocb_flush_deferred_wakeup);
static int rdp_offload_toggle(struct rcu_data *rdp,
bool offload, unsigned long flags)
@@ -2835,8 +2847,9 @@ static int rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp)
return false;
}
-static void do_nocb_deferred_wakeup(struct rcu_data *rdp)
+static bool do_nocb_deferred_wakeup(struct rcu_data *rdp)
{
+ return false;
}
static void rcu_spawn_cpu_nocb_kthread(int cpu)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 22f6748c16f6..7f5ffc878411 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -355,8 +355,9 @@ static enum hrtimer_restart hrtick(struct hrtimer *timer)
static void __hrtick_restart(struct rq *rq)
{
struct hrtimer *timer = &rq->hrtick_timer;
+ ktime_t time = rq->hrtick_time;
- hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED_HARD);
+ hrtimer_start(timer, time, HRTIMER_MODE_ABS_PINNED_HARD);
}
/*
@@ -380,7 +381,6 @@ static void __hrtick_start(void *arg)
void hrtick_start(struct rq *rq, u64 delay)
{
struct hrtimer *timer = &rq->hrtick_timer;
- ktime_t time;
s64 delta;
/*
@@ -388,9 +388,7 @@ void hrtick_start(struct rq *rq, u64 delay)
* doesn't make sense and can cause timer DoS.
*/
delta = max_t(s64, delay, 10000LL);
- time = ktime_add_ns(timer->base->get_time(), delta);
-
- hrtimer_set_expires(timer, time);
+ rq->hrtick_time = ktime_add_ns(timer->base->get_time(), delta);
if (rq == this_rq())
__hrtick_restart(rq);
@@ -4970,7 +4968,7 @@ static void __sched notrace __schedule(bool preempt)
schedule_debug(prev, preempt);
- if (sched_feat(HRTICK))
+ if (sched_feat(HRTICK) || sched_feat(HRTICK_DL))
hrtick_clear(rq);
local_irq_disable();
@@ -5264,6 +5262,12 @@ asmlinkage __visible void __sched notrace preempt_schedule(void)
NOKPROBE_SYMBOL(preempt_schedule);
EXPORT_SYMBOL(preempt_schedule);
+#ifdef CONFIG_PREEMPT_DYNAMIC
+DEFINE_STATIC_CALL(preempt_schedule, __preempt_schedule_func);
+EXPORT_STATIC_CALL_TRAMP(preempt_schedule);
+#endif
+
+
/**
* preempt_schedule_notrace - preempt_schedule called by tracing
*
@@ -5316,8 +5320,197 @@ asmlinkage __visible void __sched notrace preempt_schedule_notrace(void)
}
EXPORT_SYMBOL_GPL(preempt_schedule_notrace);
+#ifdef CONFIG_PREEMPT_DYNAMIC
+DEFINE_STATIC_CALL(preempt_schedule_notrace, __preempt_schedule_notrace_func);
+EXPORT_STATIC_CALL_TRAMP(preempt_schedule_notrace);
+#endif
+
#endif /* CONFIG_PREEMPTION */
+#ifdef CONFIG_PREEMPT_DYNAMIC
+
+#include <linux/entry-common.h>
+
+/*
+ * SC:cond_resched
+ * SC:might_resched
+ * SC:preempt_schedule
+ * SC:preempt_schedule_notrace
+ * SC:irqentry_exit_cond_resched
+ *
+ *
+ * NONE:
+ * cond_resched <- __cond_resched
+ * might_resched <- RET0
+ * preempt_schedule <- NOP
+ * preempt_schedule_notrace <- NOP
+ * irqentry_exit_cond_resched <- NOP
+ *
+ * VOLUNTARY:
+ * cond_resched <- __cond_resched
+ * might_resched <- __cond_resched
+ * preempt_schedule <- NOP
+ * preempt_schedule_notrace <- NOP
+ * irqentry_exit_cond_resched <- NOP
+ *
+ * FULL:
+ * cond_resched <- RET0
+ * might_resched <- RET0
+ * preempt_schedule <- preempt_schedule
+ * preempt_schedule_notrace <- preempt_schedule_notrace
+ * irqentry_exit_cond_resched <- irqentry_exit_cond_resched
+ */
+
+enum {
+ preempt_dynamic_none = 0,
+ preempt_dynamic_voluntary,
+ preempt_dynamic_full,
+};
+
+static int preempt_dynamic_mode = preempt_dynamic_full;
+
+static int sched_dynamic_mode(const char *str)
+{
+ if (!strcmp(str, "none"))
+ return 0;
+
+ if (!strcmp(str, "voluntary"))
+ return 1;
+
+ if (!strcmp(str, "full"))
+ return 2;
+
+ return -1;
+}
+
+static void sched_dynamic_update(int mode)
+{
+ /*
+ * Avoid {NONE,VOLUNTARY} -> FULL transitions from ever ending up in
+ * the ZERO state, which is invalid.
+ */
+ static_call_update(cond_resched, __cond_resched);
+ static_call_update(might_resched, __cond_resched);
+ static_call_update(preempt_schedule, __preempt_schedule_func);
+ static_call_update(preempt_schedule_notrace, __preempt_schedule_notrace_func);
+ static_call_update(irqentry_exit_cond_resched, irqentry_exit_cond_resched);
+
+ switch (mode) {
+ case preempt_dynamic_none:
+ static_call_update(cond_resched, __cond_resched);
+ static_call_update(might_resched, (typeof(&__cond_resched)) __static_call_return0);
+ static_call_update(preempt_schedule, (typeof(&preempt_schedule)) NULL);
+ static_call_update(preempt_schedule_notrace, (typeof(&preempt_schedule_notrace)) NULL);
+ static_call_update(irqentry_exit_cond_resched, (typeof(&irqentry_exit_cond_resched)) NULL);
+ pr_info("Dynamic Preempt: none\n");
+ break;
+
+ case preempt_dynamic_voluntary:
+ static_call_update(cond_resched, __cond_resched);
+ static_call_update(might_resched, __cond_resched);
+ static_call_update(preempt_schedule, (typeof(&preempt_schedule)) NULL);
+ static_call_update(preempt_schedule_notrace, (typeof(&preempt_schedule_notrace)) NULL);
+ static_call_update(irqentry_exit_cond_resched, (typeof(&irqentry_exit_cond_resched)) NULL);
+ pr_info("Dynamic Preempt: voluntary\n");
+ break;
+
+ case preempt_dynamic_full:
+ static_call_update(cond_resched, (typeof(&__cond_resched)) __static_call_return0);
+ static_call_update(might_resched, (typeof(&__cond_resched)) __static_call_return0);
+ static_call_update(preempt_schedule, __preempt_schedule_func);
+ static_call_update(preempt_schedule_notrace, __preempt_schedule_notrace_func);
+ static_call_update(irqentry_exit_cond_resched, irqentry_exit_cond_resched);
+ pr_info("Dynamic Preempt: full\n");
+ break;
+ }
+
+ preempt_dynamic_mode = mode;
+}
+
+static int __init setup_preempt_mode(char *str)
+{
+ int mode = sched_dynamic_mode(str);
+ if (mode < 0) {
+ pr_warn("Dynamic Preempt: unsupported mode: %s\n", str);
+ return 1;
+ }
+
+ sched_dynamic_update(mode);
+ return 0;
+}
+__setup("preempt=", setup_preempt_mode);
+
+#ifdef CONFIG_SCHED_DEBUG
+
+static ssize_t sched_dynamic_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[16];
+ int mode;
+
+ if (cnt > 15)
+ cnt = 15;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+ mode = sched_dynamic_mode(strstrip(buf));
+ if (mode < 0)
+ return mode;
+
+ sched_dynamic_update(mode);
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+static int sched_dynamic_show(struct seq_file *m, void *v)
+{
+ static const char * preempt_modes[] = {
+ "none", "voluntary", "full"
+ };
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(preempt_modes); i++) {
+ if (preempt_dynamic_mode == i)
+ seq_puts(m, "(");
+ seq_puts(m, preempt_modes[i]);
+ if (preempt_dynamic_mode == i)
+ seq_puts(m, ")");
+
+ seq_puts(m, " ");
+ }
+
+ seq_puts(m, "\n");
+ return 0;
+}
+
+static int sched_dynamic_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, sched_dynamic_show, NULL);
+}
+
+static const struct file_operations sched_dynamic_fops = {
+ .open = sched_dynamic_open,
+ .write = sched_dynamic_write,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static __init int sched_init_debug_dynamic(void)
+{
+ debugfs_create_file("sched_preempt", 0644, NULL, NULL, &sched_dynamic_fops);
+ return 0;
+}
+late_initcall(sched_init_debug_dynamic);
+
+#endif /* CONFIG_SCHED_DEBUG */
+#endif /* CONFIG_PREEMPT_DYNAMIC */
+
+
/*
* This is the entry point to schedule() from kernel preemption
* off of irq context.
@@ -5615,8 +5808,12 @@ SYSCALL_DEFINE1(nice, int, increment)
* @p: the task in question.
*
* Return: The priority value as seen by users in /proc.
- * RT tasks are offset by -200. Normal tasks are centered
- * around 0, value goes from -16 to +15.
+ *
+ * sched policy return value kernel prio user prio/nice
+ *
+ * normal, batch, idle [0 ... 39] [100 ... 139] 0/[-20 ... 19]
+ * fifo, rr [-2 ... -100] [98 ... 0] [1 ... 99]
+ * deadline -101 -1 0
*/
int task_prio(const struct task_struct *p)
{
@@ -5675,6 +5872,120 @@ struct task_struct *idle_task(int cpu)
return cpu_rq(cpu)->idle;
}
+#ifdef CONFIG_SMP
+/*
+ * This function computes an effective utilization for the given CPU, to be
+ * used for frequency selection given the linear relation: f = u * f_max.
+ *
+ * The scheduler tracks the following metrics:
+ *
+ * cpu_util_{cfs,rt,dl,irq}()
+ * cpu_bw_dl()
+ *
+ * Where the cfs,rt and dl util numbers are tracked with the same metric and
+ * synchronized windows and are thus directly comparable.
+ *
+ * The cfs,rt,dl utilization are the running times measured with rq->clock_task
+ * which excludes things like IRQ and steal-time. These latter are then accrued
+ * in the irq utilization.
+ *
+ * The DL bandwidth number otoh is not a measured metric but a value computed
+ * based on the task model parameters and gives the minimal utilization
+ * required to meet deadlines.
+ */
+unsigned long effective_cpu_util(int cpu, unsigned long util_cfs,
+ unsigned long max, enum cpu_util_type type,
+ struct task_struct *p)
+{
+ unsigned long dl_util, util, irq;
+ struct rq *rq = cpu_rq(cpu);
+
+ if (!uclamp_is_used() &&
+ type == FREQUENCY_UTIL && rt_rq_is_runnable(&rq->rt)) {
+ return max;
+ }
+
+ /*
+ * Early check to see if IRQ/steal time saturates the CPU, can be
+ * because of inaccuracies in how we track these -- see
+ * update_irq_load_avg().
+ */
+ irq = cpu_util_irq(rq);
+ if (unlikely(irq >= max))
+ return max;
+
+ /*
+ * Because the time spend on RT/DL tasks is visible as 'lost' time to
+ * CFS tasks and we use the same metric to track the effective
+ * utilization (PELT windows are synchronized) we can directly add them
+ * to obtain the CPU's actual utilization.
+ *
+ * CFS and RT utilization can be boosted or capped, depending on
+ * utilization clamp constraints requested by currently RUNNABLE
+ * tasks.
+ * When there are no CFS RUNNABLE tasks, clamps are released and
+ * frequency will be gracefully reduced with the utilization decay.
+ */
+ util = util_cfs + cpu_util_rt(rq);
+ if (type == FREQUENCY_UTIL)
+ util = uclamp_rq_util_with(rq, util, p);
+
+ dl_util = cpu_util_dl(rq);
+
+ /*
+ * For frequency selection we do not make cpu_util_dl() a permanent part
+ * of this sum because we want to use cpu_bw_dl() later on, but we need
+ * to check if the CFS+RT+DL sum is saturated (ie. no idle time) such
+ * that we select f_max when there is no idle time.
+ *
+ * NOTE: numerical errors or stop class might cause us to not quite hit
+ * saturation when we should -- something for later.
+ */
+ if (util + dl_util >= max)
+ return max;
+
+ /*
+ * OTOH, for energy computation we need the estimated running time, so
+ * include util_dl and ignore dl_bw.
+ */
+ if (type == ENERGY_UTIL)
+ util += dl_util;
+
+ /*
+ * There is still idle time; further improve the number by using the
+ * irq metric. Because IRQ/steal time is hidden from the task clock we
+ * need to scale the task numbers:
+ *
+ * max - irq
+ * U' = irq + --------- * U
+ * max
+ */
+ util = scale_irq_capacity(util, irq, max);
+ util += irq;
+
+ /*
+ * Bandwidth required by DEADLINE must always be granted while, for
+ * FAIR and RT, we use blocked utilization of IDLE CPUs as a mechanism
+ * to gracefully reduce the frequency when no tasks show up for longer
+ * periods of time.
+ *
+ * Ideally we would like to set bw_dl as min/guaranteed freq and util +
+ * bw_dl as requested freq. However, cpufreq is not yet ready for such
+ * an interface. So, we only do the latter for now.
+ */
+ if (type == FREQUENCY_UTIL)
+ util += cpu_bw_dl(rq);
+
+ return min(max, util);
+}
+
+unsigned long sched_cpu_util(int cpu, unsigned long max)
+{
+ return effective_cpu_util(cpu, cpu_util_cfs(cpu_rq(cpu)), max,
+ ENERGY_UTIL, NULL);
+}
+#endif /* CONFIG_SMP */
+
/**
* find_process_by_pid - find a process with a matching PID value.
* @pid: the pid in question.
@@ -5796,11 +6107,10 @@ recheck:
/*
* Valid priorities for SCHED_FIFO and SCHED_RR are
- * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL,
+ * 1..MAX_RT_PRIO-1, valid priority for SCHED_NORMAL,
* SCHED_BATCH and SCHED_IDLE is 0.
*/
- if ((p->mm && attr->sched_priority > MAX_USER_RT_PRIO-1) ||
- (!p->mm && attr->sched_priority > MAX_RT_PRIO-1))
+ if (attr->sched_priority > MAX_RT_PRIO-1)
return -EINVAL;
if ((dl_policy(policy) && !__checkparam_dl(attr)) ||
(rt_policy(policy) != (attr->sched_priority != 0)))
@@ -6667,17 +6977,27 @@ SYSCALL_DEFINE0(sched_yield)
return 0;
}
-#ifndef CONFIG_PREEMPTION
-int __sched _cond_resched(void)
+#if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
+int __sched __cond_resched(void)
{
if (should_resched(0)) {
preempt_schedule_common();
return 1;
}
+#ifndef CONFIG_PREEMPT_RCU
rcu_all_qs();
+#endif
return 0;
}
-EXPORT_SYMBOL(_cond_resched);
+EXPORT_SYMBOL(__cond_resched);
+#endif
+
+#ifdef CONFIG_PREEMPT_DYNAMIC
+DEFINE_STATIC_CALL_RET0(cond_resched, __cond_resched);
+EXPORT_STATIC_CALL_TRAMP(cond_resched);
+
+DEFINE_STATIC_CALL_RET0(might_resched, __cond_resched);
+EXPORT_STATIC_CALL_TRAMP(might_resched);
#endif
/*
@@ -6868,7 +7188,7 @@ SYSCALL_DEFINE1(sched_get_priority_max, int, policy)
switch (policy) {
case SCHED_FIFO:
case SCHED_RR:
- ret = MAX_USER_RT_PRIO-1;
+ ret = MAX_RT_PRIO-1;
break;
case SCHED_DEADLINE:
case SCHED_NORMAL:
@@ -7508,6 +7828,12 @@ int sched_cpu_deactivate(unsigned int cpu)
struct rq_flags rf;
int ret;
+ /*
+ * Remove CPU from nohz.idle_cpus_mask to prevent participating in
+ * load balancing when not active
+ */
+ nohz_balance_exit_idle(rq);
+
set_cpu_active(cpu, false);
/*
@@ -7652,7 +7978,6 @@ int sched_cpu_dying(unsigned int cpu)
calc_load_migrate(rq);
update_max_interval();
- nohz_balance_exit_idle(rq);
hrtick_clear(rq);
return 0;
}
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 6931f0cdeb80..41e498b0008a 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -171,112 +171,6 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy,
return cpufreq_driver_resolve_freq(policy, freq);
}
-/*
- * This function computes an effective utilization for the given CPU, to be
- * used for frequency selection given the linear relation: f = u * f_max.
- *
- * The scheduler tracks the following metrics:
- *
- * cpu_util_{cfs,rt,dl,irq}()
- * cpu_bw_dl()
- *
- * Where the cfs,rt and dl util numbers are tracked with the same metric and
- * synchronized windows and are thus directly comparable.
- *
- * The cfs,rt,dl utilization are the running times measured with rq->clock_task
- * which excludes things like IRQ and steal-time. These latter are then accrued
- * in the irq utilization.
- *
- * The DL bandwidth number otoh is not a measured metric but a value computed
- * based on the task model parameters and gives the minimal utilization
- * required to meet deadlines.
- */
-unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs,
- unsigned long max, enum schedutil_type type,
- struct task_struct *p)
-{
- unsigned long dl_util, util, irq;
- struct rq *rq = cpu_rq(cpu);
-
- if (!uclamp_is_used() &&
- type == FREQUENCY_UTIL && rt_rq_is_runnable(&rq->rt)) {
- return max;
- }
-
- /*
- * Early check to see if IRQ/steal time saturates the CPU, can be
- * because of inaccuracies in how we track these -- see
- * update_irq_load_avg().
- */
- irq = cpu_util_irq(rq);
- if (unlikely(irq >= max))
- return max;
-
- /*
- * Because the time spend on RT/DL tasks is visible as 'lost' time to
- * CFS tasks and we use the same metric to track the effective
- * utilization (PELT windows are synchronized) we can directly add them
- * to obtain the CPU's actual utilization.
- *
- * CFS and RT utilization can be boosted or capped, depending on
- * utilization clamp constraints requested by currently RUNNABLE
- * tasks.
- * When there are no CFS RUNNABLE tasks, clamps are released and
- * frequency will be gracefully reduced with the utilization decay.
- */
- util = util_cfs + cpu_util_rt(rq);
- if (type == FREQUENCY_UTIL)
- util = uclamp_rq_util_with(rq, util, p);
-
- dl_util = cpu_util_dl(rq);
-
- /*
- * For frequency selection we do not make cpu_util_dl() a permanent part
- * of this sum because we want to use cpu_bw_dl() later on, but we need
- * to check if the CFS+RT+DL sum is saturated (ie. no idle time) such
- * that we select f_max when there is no idle time.
- *
- * NOTE: numerical errors or stop class might cause us to not quite hit
- * saturation when we should -- something for later.
- */
- if (util + dl_util >= max)
- return max;
-
- /*
- * OTOH, for energy computation we need the estimated running time, so
- * include util_dl and ignore dl_bw.
- */
- if (type == ENERGY_UTIL)
- util += dl_util;
-
- /*
- * There is still idle time; further improve the number by using the
- * irq metric. Because IRQ/steal time is hidden from the task clock we
- * need to scale the task numbers:
- *
- * max - irq
- * U' = irq + --------- * U
- * max
- */
- util = scale_irq_capacity(util, irq, max);
- util += irq;
-
- /*
- * Bandwidth required by DEADLINE must always be granted while, for
- * FAIR and RT, we use blocked utilization of IDLE CPUs as a mechanism
- * to gracefully reduce the frequency when no tasks show up for longer
- * periods of time.
- *
- * Ideally we would like to set bw_dl as min/guaranteed freq and util +
- * bw_dl as requested freq. However, cpufreq is not yet ready for such
- * an interface. So, we only do the latter for now.
- */
- if (type == FREQUENCY_UTIL)
- util += cpu_bw_dl(rq);
-
- return min(max, util);
-}
-
static void sugov_get_util(struct sugov_cpu *sg_cpu)
{
struct rq *rq = cpu_rq(sg_cpu->cpu);
@@ -284,7 +178,7 @@ static void sugov_get_util(struct sugov_cpu *sg_cpu)
sg_cpu->max = max;
sg_cpu->bw_dl = cpu_bw_dl(rq);
- sg_cpu->util = schedutil_cpu_util(sg_cpu->cpu, cpu_util_cfs(rq), max,
+ sg_cpu->util = effective_cpu_util(sg_cpu->cpu, cpu_util_cfs(rq), max,
FREQUENCY_UTIL, NULL);
}
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 75686c6d4436..aac3539aa0fe 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -517,58 +517,44 @@ static void dec_dl_migration(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
update_dl_migration(dl_rq);
}
+#define __node_2_pdl(node) \
+ rb_entry((node), struct task_struct, pushable_dl_tasks)
+
+static inline bool __pushable_less(struct rb_node *a, const struct rb_node *b)
+{
+ return dl_entity_preempt(&__node_2_pdl(a)->dl, &__node_2_pdl(b)->dl);
+}
+
/*
* The list of pushable -deadline task is not a plist, like in
* sched_rt.c, it is an rb-tree with tasks ordered by deadline.
*/
static void enqueue_pushable_dl_task(struct rq *rq, struct task_struct *p)
{
- struct dl_rq *dl_rq = &rq->dl;
- struct rb_node **link = &dl_rq->pushable_dl_tasks_root.rb_root.rb_node;
- struct rb_node *parent = NULL;
- struct task_struct *entry;
- bool leftmost = true;
+ struct rb_node *leftmost;
BUG_ON(!RB_EMPTY_NODE(&p->pushable_dl_tasks));
- while (*link) {
- parent = *link;
- entry = rb_entry(parent, struct task_struct,
- pushable_dl_tasks);
- if (dl_entity_preempt(&p->dl, &entry->dl))
- link = &parent->rb_left;
- else {
- link = &parent->rb_right;
- leftmost = false;
- }
- }
-
+ leftmost = rb_add_cached(&p->pushable_dl_tasks,
+ &rq->dl.pushable_dl_tasks_root,
+ __pushable_less);
if (leftmost)
- dl_rq->earliest_dl.next = p->dl.deadline;
-
- rb_link_node(&p->pushable_dl_tasks, parent, link);
- rb_insert_color_cached(&p->pushable_dl_tasks,
- &dl_rq->pushable_dl_tasks_root, leftmost);
+ rq->dl.earliest_dl.next = p->dl.deadline;
}
static void dequeue_pushable_dl_task(struct rq *rq, struct task_struct *p)
{
struct dl_rq *dl_rq = &rq->dl;
+ struct rb_root_cached *root = &dl_rq->pushable_dl_tasks_root;
+ struct rb_node *leftmost;
if (RB_EMPTY_NODE(&p->pushable_dl_tasks))
return;
- if (dl_rq->pushable_dl_tasks_root.rb_leftmost == &p->pushable_dl_tasks) {
- struct rb_node *next_node;
-
- next_node = rb_next(&p->pushable_dl_tasks);
- if (next_node) {
- dl_rq->earliest_dl.next = rb_entry(next_node,
- struct task_struct, pushable_dl_tasks)->dl.deadline;
- }
- }
+ leftmost = rb_erase_cached(&p->pushable_dl_tasks, root);
+ if (leftmost)
+ dl_rq->earliest_dl.next = __node_2_pdl(leftmost)->dl.deadline;
- rb_erase_cached(&p->pushable_dl_tasks, &dl_rq->pushable_dl_tasks_root);
RB_CLEAR_NODE(&p->pushable_dl_tasks);
}
@@ -1478,29 +1464,21 @@ void dec_dl_tasks(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
dec_dl_migration(dl_se, dl_rq);
}
+#define __node_2_dle(node) \
+ rb_entry((node), struct sched_dl_entity, rb_node)
+
+static inline bool __dl_less(struct rb_node *a, const struct rb_node *b)
+{
+ return dl_time_before(__node_2_dle(a)->deadline, __node_2_dle(b)->deadline);
+}
+
static void __enqueue_dl_entity(struct sched_dl_entity *dl_se)
{
struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
- struct rb_node **link = &dl_rq->root.rb_root.rb_node;
- struct rb_node *parent = NULL;
- struct sched_dl_entity *entry;
- int leftmost = 1;
BUG_ON(!RB_EMPTY_NODE(&dl_se->rb_node));
- while (*link) {
- parent = *link;
- entry = rb_entry(parent, struct sched_dl_entity, rb_node);
- if (dl_time_before(dl_se->deadline, entry->deadline))
- link = &parent->rb_left;
- else {
- link = &parent->rb_right;
- leftmost = 0;
- }
- }
-
- rb_link_node(&dl_se->rb_node, parent, link);
- rb_insert_color_cached(&dl_se->rb_node, &dl_rq->root, leftmost);
+ rb_add_cached(&dl_se->rb_node, &dl_rq->root, __dl_less);
inc_dl_tasks(dl_se, dl_rq);
}
@@ -1513,6 +1491,7 @@ static void __dequeue_dl_entity(struct sched_dl_entity *dl_se)
return;
rb_erase_cached(&dl_se->rb_node, &dl_rq->root);
+
RB_CLEAR_NODE(&dl_se->rb_node);
dec_dl_tasks(dl_se, dl_rq);
@@ -1853,7 +1832,7 @@ static void set_next_task_dl(struct rq *rq, struct task_struct *p, bool first)
if (!first)
return;
- if (hrtick_enabled(rq))
+ if (hrtick_enabled_dl(rq))
start_hrtick_dl(rq, p);
if (rq->curr->sched_class != &dl_sched_class)
@@ -1916,7 +1895,7 @@ static void task_tick_dl(struct rq *rq, struct task_struct *p, int queued)
* not being the leftmost task anymore. In that case NEED_RESCHED will
* be set and schedule() will start a new hrtick for the next task.
*/
- if (hrtick_enabled(rq) && queued && p->dl.runtime > 0 &&
+ if (hrtick_enabled_dl(rq) && queued && p->dl.runtime > 0 &&
is_leftmost(p, &rq->dl))
start_hrtick_dl(rq, p);
}
@@ -2409,9 +2388,13 @@ void dl_add_task_root_domain(struct task_struct *p)
struct rq *rq;
struct dl_bw *dl_b;
- rq = task_rq_lock(p, &rf);
- if (!dl_task(p))
- goto unlock;
+ raw_spin_lock_irqsave(&p->pi_lock, rf.flags);
+ if (!dl_task(p)) {
+ raw_spin_unlock_irqrestore(&p->pi_lock, rf.flags);
+ return;
+ }
+
+ rq = __task_rq_lock(p, &rf);
dl_b = &rq->rd->dl_bw;
raw_spin_lock(&dl_b->lock);
@@ -2420,7 +2403,6 @@ void dl_add_task_root_domain(struct task_struct *p)
raw_spin_unlock(&dl_b->lock);
-unlock:
task_rq_unlock(rq, p, &rf);
}
@@ -2514,7 +2496,7 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p)
static void prio_changed_dl(struct rq *rq, struct task_struct *p,
int oldprio)
{
- if (task_on_rq_queued(p) || rq->curr == p) {
+ if (task_on_rq_queued(p) || task_current(rq, p)) {
#ifdef CONFIG_SMP
/*
* This might be too much, but unfortunately
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 2357921580f9..486f403a778b 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -486,7 +486,7 @@ static char *task_group_path(struct task_group *tg)
static void
print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
{
- if (rq->curr == p)
+ if (task_current(rq, p))
SEQ_printf(m, ">R");
else
SEQ_printf(m, " %c", task_state_to_char(p));
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 04a3ce20da67..8a8bd7b13634 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -531,12 +531,15 @@ static inline u64 min_vruntime(u64 min_vruntime, u64 vruntime)
return min_vruntime;
}
-static inline int entity_before(struct sched_entity *a,
+static inline bool entity_before(struct sched_entity *a,
struct sched_entity *b)
{
return (s64)(a->vruntime - b->vruntime) < 0;
}
+#define __node_2_se(node) \
+ rb_entry((node), struct sched_entity, run_node)
+
static void update_min_vruntime(struct cfs_rq *cfs_rq)
{
struct sched_entity *curr = cfs_rq->curr;
@@ -552,8 +555,7 @@ static void update_min_vruntime(struct cfs_rq *cfs_rq)
}
if (leftmost) { /* non-empty tree */
- struct sched_entity *se;
- se = rb_entry(leftmost, struct sched_entity, run_node);
+ struct sched_entity *se = __node_2_se(leftmost);
if (!curr)
vruntime = se->vruntime;
@@ -569,37 +571,17 @@ static void update_min_vruntime(struct cfs_rq *cfs_rq)
#endif
}
+static inline bool __entity_less(struct rb_node *a, const struct rb_node *b)
+{
+ return entity_before(__node_2_se(a), __node_2_se(b));
+}
+
/*
* Enqueue an entity into the rb-tree:
*/
static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- struct rb_node **link = &cfs_rq->tasks_timeline.rb_root.rb_node;
- struct rb_node *parent = NULL;
- struct sched_entity *entry;
- bool leftmost = true;
-
- /*
- * Find the right place in the rbtree:
- */
- while (*link) {
- parent = *link;
- entry = rb_entry(parent, struct sched_entity, run_node);
- /*
- * We dont care about collisions. Nodes with
- * the same key stay together.
- */
- if (entity_before(se, entry)) {
- link = &parent->rb_left;
- } else {
- link = &parent->rb_right;
- leftmost = false;
- }
- }
-
- rb_link_node(&se->run_node, parent, link);
- rb_insert_color_cached(&se->run_node,
- &cfs_rq->tasks_timeline, leftmost);
+ rb_add_cached(&se->run_node, &cfs_rq->tasks_timeline, __entity_less);
}
static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
@@ -614,7 +596,7 @@ struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq)
if (!left)
return NULL;
- return rb_entry(left, struct sched_entity, run_node);
+ return __node_2_se(left);
}
static struct sched_entity *__pick_next_entity(struct sched_entity *se)
@@ -624,7 +606,7 @@ static struct sched_entity *__pick_next_entity(struct sched_entity *se)
if (!next)
return NULL;
- return rb_entry(next, struct sched_entity, run_node);
+ return __node_2_se(next);
}
#ifdef CONFIG_SCHED_DEBUG
@@ -635,7 +617,7 @@ struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
if (!last)
return NULL;
- return rb_entry(last, struct sched_entity, run_node);
+ return __node_2_se(last);
}
/**************************************************************
@@ -3943,6 +3925,22 @@ static inline void util_est_enqueue(struct cfs_rq *cfs_rq,
trace_sched_util_est_cfs_tp(cfs_rq);
}
+static inline void util_est_dequeue(struct cfs_rq *cfs_rq,
+ struct task_struct *p)
+{
+ unsigned int enqueued;
+
+ if (!sched_feat(UTIL_EST))
+ return;
+
+ /* Update root cfs_rq's estimated utilization */
+ enqueued = cfs_rq->avg.util_est.enqueued;
+ enqueued -= min_t(unsigned int, enqueued, _task_util_est(p));
+ WRITE_ONCE(cfs_rq->avg.util_est.enqueued, enqueued);
+
+ trace_sched_util_est_cfs_tp(cfs_rq);
+}
+
/*
* Check if a (signed) value is within a specified (unsigned) margin,
* based on the observation that:
@@ -3956,23 +3954,16 @@ static inline bool within_margin(int value, int margin)
return ((unsigned int)(value + margin - 1) < (2 * margin - 1));
}
-static void
-util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p, bool task_sleep)
+static inline void util_est_update(struct cfs_rq *cfs_rq,
+ struct task_struct *p,
+ bool task_sleep)
{
long last_ewma_diff;
struct util_est ue;
- int cpu;
if (!sched_feat(UTIL_EST))
return;
- /* Update root cfs_rq's estimated utilization */
- ue.enqueued = cfs_rq->avg.util_est.enqueued;
- ue.enqueued -= min_t(unsigned int, ue.enqueued, _task_util_est(p));
- WRITE_ONCE(cfs_rq->avg.util_est.enqueued, ue.enqueued);
-
- trace_sched_util_est_cfs_tp(cfs_rq);
-
/*
* Skip update of task's estimated utilization when the task has not
* yet completed an activation, e.g. being migrated.
@@ -4012,8 +4003,7 @@ util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p, bool task_sleep)
* To avoid overestimation of actual task utilization, skip updates if
* we cannot grant there is idle time in this CPU.
*/
- cpu = cpu_of(rq_of(cfs_rq));
- if (task_util(p) > capacity_orig_of(cpu))
+ if (task_util(p) > capacity_orig_of(cpu_of(rq_of(cfs_rq))))
return;
/*
@@ -4052,7 +4042,7 @@ static inline void update_misfit_status(struct task_struct *p, struct rq *rq)
if (!static_branch_unlikely(&sched_asym_cpucapacity))
return;
- if (!p) {
+ if (!p || p->nr_cpus_allowed == 1) {
rq->misfit_task_load = 0;
return;
}
@@ -4096,8 +4086,11 @@ static inline void
util_est_enqueue(struct cfs_rq *cfs_rq, struct task_struct *p) {}
static inline void
-util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p,
- bool task_sleep) {}
+util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p) {}
+
+static inline void
+util_est_update(struct cfs_rq *cfs_rq, struct task_struct *p,
+ bool task_sleep) {}
static inline void update_misfit_status(struct task_struct *p, struct rq *rq) {}
#endif /* CONFIG_SMP */
@@ -5419,7 +5412,7 @@ static void hrtick_start_fair(struct rq *rq, struct task_struct *p)
s64 delta = slice - ran;
if (delta < 0) {
- if (rq->curr == p)
+ if (task_current(rq, p))
resched_curr(rq);
return;
}
@@ -5436,7 +5429,7 @@ static void hrtick_update(struct rq *rq)
{
struct task_struct *curr = rq->curr;
- if (!hrtick_enabled(rq) || curr->sched_class != &fair_sched_class)
+ if (!hrtick_enabled_fair(rq) || curr->sched_class != &fair_sched_class)
return;
if (cfs_rq_of(&curr->se)->nr_running < sched_nr_latency)
@@ -5609,6 +5602,8 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
int idle_h_nr_running = task_has_idle_policy(p);
bool was_sched_idle = sched_idle_rq(rq);
+ util_est_dequeue(&rq->cfs, p);
+
for_each_sched_entity(se) {
cfs_rq = cfs_rq_of(se);
dequeue_entity(cfs_rq, se, flags);
@@ -5659,7 +5654,7 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
rq->next_balance = jiffies;
dequeue_throttle:
- util_est_dequeue(&rq->cfs, p, task_sleep);
+ util_est_update(&rq->cfs, p, task_sleep);
hrtick_update(rq);
}
@@ -6006,6 +6001,14 @@ static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p
return new_cpu;
}
+static inline int __select_idle_cpu(int cpu)
+{
+ if (available_idle_cpu(cpu) || sched_idle_cpu(cpu))
+ return cpu;
+
+ return -1;
+}
+
#ifdef CONFIG_SCHED_SMT
DEFINE_STATIC_KEY_FALSE(sched_smt_present);
EXPORT_SYMBOL_GPL(sched_smt_present);
@@ -6064,74 +6067,51 @@ unlock:
* there are no idle cores left in the system; tracked through
* sd_llc->shared->has_idle_cores and enabled through update_idle_core() above.
*/
-static int select_idle_core(struct task_struct *p, struct sched_domain *sd, int target)
+static int select_idle_core(struct task_struct *p, int core, struct cpumask *cpus, int *idle_cpu)
{
- struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask);
- int core, cpu;
+ bool idle = true;
+ int cpu;
if (!static_branch_likely(&sched_smt_present))
- return -1;
+ return __select_idle_cpu(core);
- if (!test_idle_cores(target, false))
- return -1;
-
- cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);
-
- for_each_cpu_wrap(core, cpus, target) {
- bool idle = true;
-
- for_each_cpu(cpu, cpu_smt_mask(core)) {
- if (!available_idle_cpu(cpu)) {
- idle = false;
- break;
+ for_each_cpu(cpu, cpu_smt_mask(core)) {
+ if (!available_idle_cpu(cpu)) {
+ idle = false;
+ if (*idle_cpu == -1) {
+ if (sched_idle_cpu(cpu) && cpumask_test_cpu(cpu, p->cpus_ptr)) {
+ *idle_cpu = cpu;
+ break;
+ }
+ continue;
}
+ break;
}
-
- if (idle)
- return core;
-
- cpumask_andnot(cpus, cpus, cpu_smt_mask(core));
+ if (*idle_cpu == -1 && cpumask_test_cpu(cpu, p->cpus_ptr))
+ *idle_cpu = cpu;
}
- /*
- * Failed to find an idle core; stop looking for one.
- */
- set_idle_cores(target, 0);
+ if (idle)
+ return core;
+ cpumask_andnot(cpus, cpus, cpu_smt_mask(core));
return -1;
}
-/*
- * Scan the local SMT mask for idle CPUs.
- */
-static int select_idle_smt(struct task_struct *p, struct sched_domain *sd, int target)
-{
- int cpu;
-
- if (!static_branch_likely(&sched_smt_present))
- return -1;
-
- for_each_cpu(cpu, cpu_smt_mask(target)) {
- if (!cpumask_test_cpu(cpu, p->cpus_ptr) ||
- !cpumask_test_cpu(cpu, sched_domain_span(sd)))
- continue;
- if (available_idle_cpu(cpu) || sched_idle_cpu(cpu))
- return cpu;
- }
+#else /* CONFIG_SCHED_SMT */
- return -1;
+static inline void set_idle_cores(int cpu, int val)
+{
}
-#else /* CONFIG_SCHED_SMT */
-
-static inline int select_idle_core(struct task_struct *p, struct sched_domain *sd, int target)
+static inline bool test_idle_cores(int cpu, bool def)
{
- return -1;
+ return def;
}
-static inline int select_idle_smt(struct task_struct *p, struct sched_domain *sd, int target)
+static inline int select_idle_core(struct task_struct *p, int core, struct cpumask *cpus, int *idle_cpu)
{
- return -1;
+ return __select_idle_cpu(core);
}
#endif /* CONFIG_SCHED_SMT */
@@ -6144,49 +6124,61 @@ static inline int select_idle_smt(struct task_struct *p, struct sched_domain *sd
static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int target)
{
struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask);
+ int i, cpu, idle_cpu = -1, nr = INT_MAX;
+ bool smt = test_idle_cores(target, false);
+ int this = smp_processor_id();
struct sched_domain *this_sd;
- u64 avg_cost, avg_idle;
u64 time;
- int this = smp_processor_id();
- int cpu, nr = INT_MAX;
this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc));
if (!this_sd)
return -1;
- /*
- * Due to large variance we need a large fuzz factor; hackbench in
- * particularly is sensitive here.
- */
- avg_idle = this_rq()->avg_idle / 512;
- avg_cost = this_sd->avg_scan_cost + 1;
+ cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);
- if (sched_feat(SIS_AVG_CPU) && avg_idle < avg_cost)
- return -1;
+ if (sched_feat(SIS_PROP) && !smt) {
+ u64 avg_cost, avg_idle, span_avg;
+
+ /*
+ * Due to large variance we need a large fuzz factor;
+ * hackbench in particularly is sensitive here.
+ */
+ avg_idle = this_rq()->avg_idle / 512;
+ avg_cost = this_sd->avg_scan_cost + 1;
- if (sched_feat(SIS_PROP)) {
- u64 span_avg = sd->span_weight * avg_idle;
+ span_avg = sd->span_weight * avg_idle;
if (span_avg > 4*avg_cost)
nr = div_u64(span_avg, avg_cost);
else
nr = 4;
- }
-
- time = cpu_clock(this);
- cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);
+ time = cpu_clock(this);
+ }
for_each_cpu_wrap(cpu, cpus, target) {
- if (!--nr)
- return -1;
- if (available_idle_cpu(cpu) || sched_idle_cpu(cpu))
- break;
+ if (smt) {
+ i = select_idle_core(p, cpu, cpus, &idle_cpu);
+ if ((unsigned int)i < nr_cpumask_bits)
+ return i;
+
+ } else {
+ if (!--nr)
+ return -1;
+ idle_cpu = __select_idle_cpu(cpu);
+ if ((unsigned int)idle_cpu < nr_cpumask_bits)
+ break;
+ }
}
- time = cpu_clock(this) - time;
- update_avg(&this_sd->avg_scan_cost, time);
+ if (smt)
+ set_idle_cores(this, false);
- return cpu;
+ if (sched_feat(SIS_PROP) && !smt) {
+ time = cpu_clock(this) - time;
+ update_avg(&this_sd->avg_scan_cost, time);
+ }
+
+ return idle_cpu;
}
/*
@@ -6315,18 +6307,10 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
if (!sd)
return target;
- i = select_idle_core(p, sd, target);
- if ((unsigned)i < nr_cpumask_bits)
- return i;
-
i = select_idle_cpu(p, sd, target);
if ((unsigned)i < nr_cpumask_bits)
return i;
- i = select_idle_smt(p, sd, target);
- if ((unsigned)i < nr_cpumask_bits)
- return i;
-
return target;
}
@@ -6543,7 +6527,7 @@ compute_energy(struct task_struct *p, int dst_cpu, struct perf_domain *pd)
* is already enough to scale the EM reported power
* consumption at the (eventually clamped) cpu_capacity.
*/
- sum_util += schedutil_cpu_util(cpu, util_cfs, cpu_cap,
+ sum_util += effective_cpu_util(cpu, util_cfs, cpu_cap,
ENERGY_UTIL, NULL);
/*
@@ -6553,7 +6537,7 @@ compute_energy(struct task_struct *p, int dst_cpu, struct perf_domain *pd)
* NOTE: in case RT tasks are running, by default the
* FREQUENCY_UTIL's utilization can be max OPP.
*/
- cpu_util = schedutil_cpu_util(cpu, util_cfs, cpu_cap,
+ cpu_util = effective_cpu_util(cpu, util_cfs, cpu_cap,
FREQUENCY_UTIL, tsk);
max_util = max(max_util, cpu_util);
}
@@ -6651,7 +6635,7 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu)
* IOW, placing the task there would make the CPU
* overutilized. Take uclamp into account to see how
* much capacity we can get out of the CPU; this is
- * aligned with schedutil_cpu_util().
+ * aligned with sched_cpu_util().
*/
util = uclamp_rq_util_with(cpu_rq(cpu), util, p);
if (!fits_capacity(util, cpu_cap))
@@ -7132,7 +7116,7 @@ done: __maybe_unused;
list_move(&p->se.group_node, &rq->cfs_tasks);
#endif
- if (hrtick_enabled(rq))
+ if (hrtick_enabled_fair(rq))
hrtick_start_fair(rq, p);
update_misfit_status(p, rq);
@@ -9389,8 +9373,11 @@ static struct rq *find_busiest_queue(struct lb_env *env,
if (rt > env->fbq_type)
continue;
- capacity = capacity_of(i);
nr_running = rq->cfs.h_nr_running;
+ if (!nr_running)
+ continue;
+
+ capacity = capacity_of(i);
/*
* For ASYM_CPUCAPACITY domains, don't pick a CPU that could
@@ -9496,13 +9483,32 @@ asym_active_balance(struct lb_env *env)
}
static inline bool
-voluntary_active_balance(struct lb_env *env)
+imbalanced_active_balance(struct lb_env *env)
+{
+ struct sched_domain *sd = env->sd;
+
+ /*
+ * The imbalanced case includes the case of pinned tasks preventing a fair
+ * distribution of the load on the system but also the even distribution of the
+ * threads on a system with spare capacity
+ */
+ if ((env->migration_type == migrate_task) &&
+ (sd->nr_balance_failed > sd->cache_nice_tries+2))
+ return 1;
+
+ return 0;
+}
+
+static int need_active_balance(struct lb_env *env)
{
struct sched_domain *sd = env->sd;
if (asym_active_balance(env))
return 1;
+ if (imbalanced_active_balance(env))
+ return 1;
+
/*
* The dst_cpu is idle and the src_cpu CPU has only 1 CFS task.
* It's worth migrating the task if the src_cpu's capacity is reduced
@@ -9522,16 +9528,6 @@ voluntary_active_balance(struct lb_env *env)
return 0;
}
-static int need_active_balance(struct lb_env *env)
-{
- struct sched_domain *sd = env->sd;
-
- if (voluntary_active_balance(env))
- return 1;
-
- return unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2);
-}
-
static int active_load_balance_cpu_stop(void *data);
static int should_we_balance(struct lb_env *env)
@@ -9623,6 +9619,8 @@ redo:
env.src_rq = busiest;
ld_moved = 0;
+ /* Clear this flag as soon as we find a pullable task */
+ env.flags |= LBF_ALL_PINNED;
if (busiest->nr_running > 1) {
/*
* Attempt to move tasks. If find_busiest_group has found
@@ -9630,7 +9628,6 @@ redo:
* still unbalanced. ld_moved simply stays zero, so it is
* correctly treated as an imbalance.
*/
- env.flags |= LBF_ALL_PINNED;
env.loop_max = min(sysctl_sched_nr_migrate, busiest->nr_running);
more_balance:
@@ -9756,10 +9753,12 @@ more_balance:
if (!cpumask_test_cpu(this_cpu, busiest->curr->cpus_ptr)) {
raw_spin_unlock_irqrestore(&busiest->lock,
flags);
- env.flags |= LBF_ALL_PINNED;
goto out_one_pinned;
}
+ /* Record that we found at least one task that could run on this_cpu */
+ env.flags &= ~LBF_ALL_PINNED;
+
/*
* ->active_balance synchronizes accesses to
* ->active_balance_work. Once set, it's cleared
@@ -9781,21 +9780,13 @@ more_balance:
/* We've kicked active balancing, force task migration. */
sd->nr_balance_failed = sd->cache_nice_tries+1;
}
- } else
+ } else {
sd->nr_balance_failed = 0;
+ }
- if (likely(!active_balance) || voluntary_active_balance(&env)) {
+ if (likely(!active_balance) || need_active_balance(&env)) {
/* We were unbalanced, so reset the balancing interval */
sd->balance_interval = sd->min_interval;
- } else {
- /*
- * If we've begun active balancing, start to back off. This
- * case may not be covered by the all_pinned logic if there
- * is only 1 task on the busy runqueue (because we don't call
- * detach_tasks).
- */
- if (sd->balance_interval < sd->max_interval)
- sd->balance_interval *= 2;
}
goto out;
@@ -10700,8 +10691,11 @@ static __latent_entropy void run_rebalance_domains(struct softirq_action *h)
*/
void trigger_load_balance(struct rq *rq)
{
- /* Don't need to rebalance while attached to NULL domain */
- if (unlikely(on_null_domain(rq)))
+ /*
+ * Don't need to rebalance while attached to NULL domain or
+ * runqueue CPU is not active
+ */
+ if (unlikely(on_null_domain(rq) || !cpu_active(cpu_of(rq))))
return;
if (time_after_eq(jiffies, rq->next_balance))
@@ -10806,7 +10800,7 @@ prio_changed_fair(struct rq *rq, struct task_struct *p, int oldprio)
* our priority decreased, or if we are not currently running on
* this runqueue and our priority is higher than the current's
*/
- if (rq->curr == p) {
+ if (task_current(rq, p)) {
if (p->prio > oldprio)
resched_curr(rq);
} else
@@ -10939,7 +10933,7 @@ static void switched_to_fair(struct rq *rq, struct task_struct *p)
* kick off the schedule if running, otherwise just see
* if we can still preempt the current task.
*/
- if (rq->curr == p)
+ if (task_current(rq, p))
resched_curr(rq);
else
check_preempt_curr(rq, p, 0);
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 68d369cba9e4..1bc2b158fc51 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -38,6 +38,7 @@ SCHED_FEAT(CACHE_HOT_BUDDY, true)
SCHED_FEAT(WAKEUP_PREEMPTION, true)
SCHED_FEAT(HRTICK, false)
+SCHED_FEAT(HRTICK_DL, false)
SCHED_FEAT(DOUBLE_TICK, false)
/*
@@ -54,7 +55,6 @@ SCHED_FEAT(TTWU_QUEUE, true)
/*
* When doing wakeups, attempt to limit superfluous scans of the LLC domain.
*/
-SCHED_FEAT(SIS_AVG_CPU, false)
SCHED_FEAT(SIS_PROP, true)
/*
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index 305727ea0677..7199e6f23789 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -285,6 +285,7 @@ static void do_idle(void)
}
arch_cpu_idle_enter();
+ rcu_nocb_flush_deferred_wakeup();
/*
* In poll mode we reenable interrupts and spin. Also if we
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index dbe4629cf7ba..8f720b71d13d 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -2357,7 +2357,7 @@ prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
if (!task_on_rq_queued(p))
return;
- if (rq->curr == p) {
+ if (task_current(rq, p)) {
#ifdef CONFIG_SMP
/*
* If our priority decreases while running, we
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index bb09988451a0..10a1522b1e30 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -140,7 +140,7 @@ extern void call_trace_sched_update_nr_running(struct rq *rq, int count);
* scale_load() and scale_load_down(w) to convert between them. The
* following must be true:
*
- * scale_load(sched_prio_to_weight[USER_PRIO(NICE_TO_PRIO(0))]) == NICE_0_LOAD
+ * scale_load(sched_prio_to_weight[NICE_TO_PRIO(0)-MAX_RT_PRIO]) == NICE_0_LOAD
*
*/
#define NICE_0_LOAD (1L << NICE_0_LOAD_SHIFT)
@@ -1031,6 +1031,7 @@ struct rq {
call_single_data_t hrtick_csd;
#endif
struct hrtimer hrtick_timer;
+ ktime_t hrtick_time;
#endif
#ifdef CONFIG_SCHEDSTATS
@@ -2104,17 +2105,39 @@ extern const_debug unsigned int sysctl_sched_migration_cost;
*/
static inline int hrtick_enabled(struct rq *rq)
{
- if (!sched_feat(HRTICK))
- return 0;
if (!cpu_active(cpu_of(rq)))
return 0;
return hrtimer_is_hres_active(&rq->hrtick_timer);
}
+static inline int hrtick_enabled_fair(struct rq *rq)
+{
+ if (!sched_feat(HRTICK))
+ return 0;
+ return hrtick_enabled(rq);
+}
+
+static inline int hrtick_enabled_dl(struct rq *rq)
+{
+ if (!sched_feat(HRTICK_DL))
+ return 0;
+ return hrtick_enabled(rq);
+}
+
void hrtick_start(struct rq *rq, u64 delay);
#else
+static inline int hrtick_enabled_fair(struct rq *rq)
+{
+ return 0;
+}
+
+static inline int hrtick_enabled_dl(struct rq *rq)
+{
+ return 0;
+}
+
static inline int hrtick_enabled(struct rq *rq)
{
return 0;
@@ -2558,27 +2581,24 @@ static inline unsigned long capacity_orig_of(int cpu)
{
return cpu_rq(cpu)->cpu_capacity_orig;
}
-#endif
/**
- * enum schedutil_type - CPU utilization type
+ * enum cpu_util_type - CPU utilization type
* @FREQUENCY_UTIL: Utilization used to select frequency
* @ENERGY_UTIL: Utilization used during energy calculation
*
* The utilization signals of all scheduling classes (CFS/RT/DL) and IRQ time
* need to be aggregated differently depending on the usage made of them. This
- * enum is used within schedutil_freq_util() to differentiate the types of
+ * enum is used within effective_cpu_util() to differentiate the types of
* utilization expected by the callers, and adjust the aggregation accordingly.
*/
-enum schedutil_type {
+enum cpu_util_type {
FREQUENCY_UTIL,
ENERGY_UTIL,
};
-#ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL
-
-unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs,
- unsigned long max, enum schedutil_type type,
+unsigned long effective_cpu_util(int cpu, unsigned long util_cfs,
+ unsigned long max, enum cpu_util_type type,
struct task_struct *p);
static inline unsigned long cpu_bw_dl(struct rq *rq)
@@ -2607,14 +2627,7 @@ static inline unsigned long cpu_util_rt(struct rq *rq)
{
return READ_ONCE(rq->avg_rt.util_avg);
}
-#else /* CONFIG_CPU_FREQ_GOV_SCHEDUTIL */
-static inline unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs,
- unsigned long max, enum schedutil_type type,
- struct task_struct *p)
-{
- return 0;
-}
-#endif /* CONFIG_CPU_FREQ_GOV_SCHEDUTIL */
+#endif
#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
static inline unsigned long cpu_util_irq(struct rq *rq)
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 5d3675c7a76b..09d35044bd88 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1596,66 +1596,58 @@ static void init_numa_topology_type(void)
}
}
+
+#define NR_DISTANCE_VALUES (1 << DISTANCE_BITS)
+
void sched_init_numa(void)
{
- int next_distance, curr_distance = node_distance(0, 0);
struct sched_domain_topology_level *tl;
- int level = 0;
- int i, j, k;
-
- sched_domains_numa_distance = kzalloc(sizeof(int) * (nr_node_ids + 1), GFP_KERNEL);
- if (!sched_domains_numa_distance)
- return;
-
- /* Includes NUMA identity node at level 0. */
- sched_domains_numa_distance[level++] = curr_distance;
- sched_domains_numa_levels = level;
+ unsigned long *distance_map;
+ int nr_levels = 0;
+ int i, j;
/*
* O(nr_nodes^2) deduplicating selection sort -- in order to find the
* unique distances in the node_distance() table.
- *
- * Assumes node_distance(0,j) includes all distances in
- * node_distance(i,j) in order to avoid cubic time.
*/
- next_distance = curr_distance;
+ distance_map = bitmap_alloc(NR_DISTANCE_VALUES, GFP_KERNEL);
+ if (!distance_map)
+ return;
+
+ bitmap_zero(distance_map, NR_DISTANCE_VALUES);
for (i = 0; i < nr_node_ids; i++) {
for (j = 0; j < nr_node_ids; j++) {
- for (k = 0; k < nr_node_ids; k++) {
- int distance = node_distance(i, k);
-
- if (distance > curr_distance &&
- (distance < next_distance ||
- next_distance == curr_distance))
- next_distance = distance;
-
- /*
- * While not a strong assumption it would be nice to know
- * about cases where if node A is connected to B, B is not
- * equally connected to A.
- */
- if (sched_debug() && node_distance(k, i) != distance)
- sched_numa_warn("Node-distance not symmetric");
+ int distance = node_distance(i, j);
- if (sched_debug() && i && !find_numa_distance(distance))
- sched_numa_warn("Node-0 not representative");
+ if (distance < LOCAL_DISTANCE || distance >= NR_DISTANCE_VALUES) {
+ sched_numa_warn("Invalid distance value range");
+ return;
}
- if (next_distance != curr_distance) {
- sched_domains_numa_distance[level++] = next_distance;
- sched_domains_numa_levels = level;
- curr_distance = next_distance;
- } else break;
+
+ bitmap_set(distance_map, distance, 1);
}
+ }
+ /*
+ * We can now figure out how many unique distance values there are and
+ * allocate memory accordingly.
+ */
+ nr_levels = bitmap_weight(distance_map, NR_DISTANCE_VALUES);
- /*
- * In case of sched_debug() we verify the above assumption.
- */
- if (!sched_debug())
- break;
+ sched_domains_numa_distance = kcalloc(nr_levels, sizeof(int), GFP_KERNEL);
+ if (!sched_domains_numa_distance) {
+ bitmap_free(distance_map);
+ return;
+ }
+
+ for (i = 0, j = 0; i < nr_levels; i++, j++) {
+ j = find_next_bit(distance_map, NR_DISTANCE_VALUES, j);
+ sched_domains_numa_distance[i] = j;
}
+ bitmap_free(distance_map);
+
/*
- * 'level' contains the number of unique distances
+ * 'nr_levels' contains the number of unique distances
*
* The sched_domains_numa_distance[] array includes the actual distance
* numbers.
@@ -1664,15 +1656,15 @@ void sched_init_numa(void)
/*
* Here, we should temporarily reset sched_domains_numa_levels to 0.
* If it fails to allocate memory for array sched_domains_numa_masks[][],
- * the array will contain less then 'level' members. This could be
+ * the array will contain less then 'nr_levels' members. This could be
* dangerous when we use it to iterate array sched_domains_numa_masks[][]
* in other functions.
*
- * We reset it to 'level' at the end of this function.
+ * We reset it to 'nr_levels' at the end of this function.
*/
sched_domains_numa_levels = 0;
- sched_domains_numa_masks = kzalloc(sizeof(void *) * level, GFP_KERNEL);
+ sched_domains_numa_masks = kzalloc(sizeof(void *) * nr_levels, GFP_KERNEL);
if (!sched_domains_numa_masks)
return;
@@ -1680,7 +1672,7 @@ void sched_init_numa(void)
* Now for each level, construct a mask per node which contains all
* CPUs of nodes that are that many hops away from us.
*/
- for (i = 0; i < level; i++) {
+ for (i = 0; i < nr_levels; i++) {
sched_domains_numa_masks[i] =
kzalloc(nr_node_ids * sizeof(void *), GFP_KERNEL);
if (!sched_domains_numa_masks[i])
@@ -1688,12 +1680,17 @@ void sched_init_numa(void)
for (j = 0; j < nr_node_ids; j++) {
struct cpumask *mask = kzalloc(cpumask_size(), GFP_KERNEL);
+ int k;
+
if (!mask)
return;
sched_domains_numa_masks[i][j] = mask;
for_each_node(k) {
+ if (sched_debug() && (node_distance(j, k) != node_distance(k, j)))
+ sched_numa_warn("Node-distance not symmetric");
+
if (node_distance(j, k) > sched_domains_numa_distance[i])
continue;
@@ -1705,7 +1702,7 @@ void sched_init_numa(void)
/* Compute default topology size */
for (i = 0; sched_domain_topology[i].mask; i++);
- tl = kzalloc((i + level + 1) *
+ tl = kzalloc((i + nr_levels + 1) *
sizeof(struct sched_domain_topology_level), GFP_KERNEL);
if (!tl)
return;
@@ -1728,7 +1725,7 @@ void sched_init_numa(void)
/*
* .. and append 'j' levels of NUMA goodness.
*/
- for (j = 1; j < level; i++, j++) {
+ for (j = 1; j < nr_levels; i++, j++) {
tl[i] = (struct sched_domain_topology_level){
.mask = sd_numa_mask,
.sd_flags = cpu_numa_flags,
@@ -1740,8 +1737,8 @@ void sched_init_numa(void)
sched_domain_topology = tl;
- sched_domains_numa_levels = level;
- sched_max_numa_distance = sched_domains_numa_distance[level - 1];
+ sched_domains_numa_levels = nr_levels;
+ sched_max_numa_distance = sched_domains_numa_distance[nr_levels - 1];
init_numa_topology_type();
}
diff --git a/kernel/smp.c b/kernel/smp.c
index 1b6070bf97bb..aeb0adfa0606 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -14,6 +14,7 @@
#include <linux/export.h>
#include <linux/percpu.h>
#include <linux/init.h>
+#include <linux/interrupt.h>
#include <linux/gfp.h>
#include <linux/smp.h>
#include <linux/cpu.h>
@@ -449,6 +450,9 @@ void flush_smp_call_function_from_idle(void)
local_irq_save(flags);
flush_smp_call_function_queue(true);
+ if (local_softirq_pending())
+ do_softirq();
+
local_irq_restore(flags);
}
diff --git a/kernel/static_call.c b/kernel/static_call.c
index 84565c2a41b8..6906c6ec4c97 100644
--- a/kernel/static_call.c
+++ b/kernel/static_call.c
@@ -12,6 +12,8 @@
extern struct static_call_site __start_static_call_sites[],
__stop_static_call_sites[];
+extern struct static_call_tramp_key __start_static_call_tramp_key[],
+ __stop_static_call_tramp_key[];
static bool static_call_initialized;
@@ -323,10 +325,59 @@ static int __static_call_mod_text_reserved(void *start, void *end)
return ret;
}
+static unsigned long tramp_key_lookup(unsigned long addr)
+{
+ struct static_call_tramp_key *start = __start_static_call_tramp_key;
+ struct static_call_tramp_key *stop = __stop_static_call_tramp_key;
+ struct static_call_tramp_key *tramp_key;
+
+ for (tramp_key = start; tramp_key != stop; tramp_key++) {
+ unsigned long tramp;
+
+ tramp = (long)tramp_key->tramp + (long)&tramp_key->tramp;
+ if (tramp == addr)
+ return (long)tramp_key->key + (long)&tramp_key->key;
+ }
+
+ return 0;
+}
+
static int static_call_add_module(struct module *mod)
{
- return __static_call_init(mod, mod->static_call_sites,
- mod->static_call_sites + mod->num_static_call_sites);
+ struct static_call_site *start = mod->static_call_sites;
+ struct static_call_site *stop = start + mod->num_static_call_sites;
+ struct static_call_site *site;
+
+ for (site = start; site != stop; site++) {
+ unsigned long addr = (unsigned long)static_call_key(site);
+ unsigned long key;
+
+ /*
+ * Is the key is exported, 'addr' points to the key, which
+ * means modules are allowed to call static_call_update() on
+ * it.
+ *
+ * Otherwise, the key isn't exported, and 'addr' points to the
+ * trampoline so we need to lookup the key.
+ *
+ * We go through this dance to prevent crazy modules from
+ * abusing sensitive static calls.
+ */
+ if (!kernel_text_address(addr))
+ continue;
+
+ key = tramp_key_lookup(addr);
+ if (!key) {
+ pr_warn("Failed to fixup __raw_static_call() usage at: %ps\n",
+ static_call_addr(site));
+ return -EINVAL;
+ }
+
+ site->key = (key - (long)&site->key) |
+ (site->key & STATIC_CALL_SITE_FLAGS);
+ }
+
+ return __static_call_init(mod, start, stop);
}
static void static_call_del_module(struct module *mod)
@@ -438,6 +489,11 @@ int __init static_call_init(void)
}
early_initcall(static_call_init);
+long __static_call_return0(void)
+{
+ return 0;
+}
+
#ifdef CONFIG_STATIC_CALL_SELFTEST
static int func_a(int x)