diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c index 88e466b159dcac92a13d81b5919b0a5487d63830..43b39d61b538698229a23f654b7fb44a335187b3 100644 --- a/arch/um/drivers/mconsole_kern.c +++ b/arch/um/drivers/mconsole_kern.c @@ -705,7 +705,6 @@ static void stack_proc(void *arg) struct task_struct *from = current, *to = arg; to->thread.saved_task = from; - rcu_switch_from(from); switch_to(from, to, from); } diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 26d1a47591f1534306160811967248ed9ecfcc12..9cac722b169c9a1f5dbcae489d7b4c43a4fbe1a2 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -184,7 +184,6 @@ static inline int rcu_preempt_depth(void) /* Internal to kernel */ extern void rcu_sched_qs(int cpu); extern void rcu_bh_qs(int cpu); -extern void rcu_preempt_note_context_switch(void); extern void rcu_check_callbacks(int cpu, int user); struct notifier_block; extern void rcu_idle_enter(void); diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 854dc4c5c27151adeaba69ddd98ac2b91831c1d4..4e56a9c69a356ca73fcd06cf775f337276f77f2e 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -87,6 +87,10 @@ static inline void kfree_call_rcu(struct rcu_head *head, #ifdef CONFIG_TINY_RCU +static inline void rcu_preempt_note_context_switch(void) +{ +} + static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) { *delta_jiffies = ULONG_MAX; @@ -95,6 +99,7 @@ static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) #else /* #ifdef CONFIG_TINY_RCU */ +void rcu_preempt_note_context_switch(void); int rcu_preempt_needs_cpu(void); static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) @@ -108,6 +113,7 @@ static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) static inline void rcu_note_context_switch(int cpu) { rcu_sched_qs(cpu); + rcu_preempt_note_context_switch(); } /* diff --git a/include/linux/sched.h b/include/linux/sched.h index 4059c0f33f07a7454d545753281898d92e2d657f..06a4c5f4f55c0c1a592993b5155e289d033e9b67 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1871,22 +1871,12 @@ static inline void rcu_copy_process(struct task_struct *p) INIT_LIST_HEAD(&p->rcu_node_entry); } -static inline void rcu_switch_from(struct task_struct *prev) -{ - if (prev->rcu_read_lock_nesting != 0) - rcu_preempt_note_context_switch(); -} - #else static inline void rcu_copy_process(struct task_struct *p) { } -static inline void rcu_switch_from(struct task_struct *prev) -{ -} - #endif #ifdef CONFIG_SMP diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 38ecdda3f55f6b3e503cf12e447c1801ae3c2812..4b97bba7396e6194db4bf5b644ef8b5a1997c974 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -201,6 +201,7 @@ void rcu_note_context_switch(int cpu) { trace_rcu_utilization("Start context switch"); rcu_sched_qs(cpu); + rcu_preempt_note_context_switch(cpu); trace_rcu_utilization("End context switch"); } EXPORT_SYMBOL_GPL(rcu_note_context_switch); diff --git a/kernel/rcutree.h b/kernel/rcutree.h index ea056495783e1a09c482802bd2e66d0c863c8a35..19b61ac1079f825702a7f17ae7d8dec88756c141 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -444,6 +444,7 @@ DECLARE_PER_CPU(char, rcu_cpu_has_work); /* Forward declarations for rcutree_plugin.h */ static void rcu_bootup_announce(void); long rcu_batches_completed(void); +static void rcu_preempt_note_context_switch(int cpu); static int rcu_preempt_blocked_readers_cgp(struct rcu_node *rnp); #ifdef CONFIG_HOTPLUG_CPU static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 5271a020887e6ea515aa29c9f52f9f612d9056ac..3e4899459f3d9d7177ee67d41b8ea1121ddb9540 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -153,7 +153,7 @@ static void rcu_preempt_qs(int cpu) * * Caller must disable preemption. */ -void rcu_preempt_note_context_switch(void) +static void rcu_preempt_note_context_switch(int cpu) { struct task_struct *t = current; unsigned long flags; @@ -164,7 +164,7 @@ void rcu_preempt_note_context_switch(void) (t->rcu_read_unlock_special & RCU_READ_UNLOCK_BLOCKED) == 0) { /* Possibly blocking in an RCU read-side critical section. */ - rdp = __this_cpu_ptr(rcu_preempt_state.rda); + rdp = per_cpu_ptr(rcu_preempt_state.rda, cpu); rnp = rdp->mynode; raw_spin_lock_irqsave(&rnp->lock, flags); t->rcu_read_unlock_special |= RCU_READ_UNLOCK_BLOCKED; @@ -228,7 +228,7 @@ void rcu_preempt_note_context_switch(void) * means that we continue to block the current grace period. */ local_irq_save(flags); - rcu_preempt_qs(smp_processor_id()); + rcu_preempt_qs(cpu); local_irq_restore(flags); } @@ -1001,6 +1001,14 @@ void rcu_force_quiescent_state(void) } EXPORT_SYMBOL_GPL(rcu_force_quiescent_state); +/* + * Because preemptible RCU does not exist, we never have to check for + * CPUs being in quiescent states. + */ +static void rcu_preempt_note_context_switch(int cpu) +{ +} + /* * Because preemptible RCU does not exist, there are never any preempted * RCU readers. diff --git a/kernel/sched/core.c b/kernel/sched/core.c index d5594a4268d4a5bb531bcf86dfc66fe359e7c956..eaead2df6aa8f19f70da1b8ae3758bfa15fc2ea2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2081,7 +2081,6 @@ context_switch(struct rq *rq, struct task_struct *prev, #endif /* Here we just switch the register state and the stack. */ - rcu_switch_from(prev); switch_to(prev, next, prev); barrier();