From: Lihao Liang <[email protected]> This is PRCU's counterpart of RCU's call_rcu() API.
Reviewed-by: Heng Zhang <[email protected]> Signed-off-by: Lihao Liang <[email protected]> --- include/linux/prcu.h | 25 ++++++++++++++++++++ init/main.c | 2 ++ kernel/rcu/prcu.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++++--- 3 files changed, 91 insertions(+), 3 deletions(-) diff --git a/include/linux/prcu.h b/include/linux/prcu.h index 653b4633..e5e09c9b 100644 --- a/include/linux/prcu.h +++ b/include/linux/prcu.h @@ -2,15 +2,36 @@ #define __LINUX_PRCU_H #include <linux/atomic.h> +#include <linux/types.h> #include <linux/mutex.h> #include <linux/wait.h> #define CONFIG_PRCU +struct prcu_version_head { + unsigned long long version; + struct prcu_version_head *next; +}; + +/* Simple unsegmented callback list for PRCU. */ +struct prcu_cblist { + struct rcu_head *head; + struct rcu_head **tail; + struct prcu_version_head *version_head; + struct prcu_version_head **version_tail; + long len; +}; + +#define PRCU_CBLIST_INITIALIZER(n) { \ + .head = NULL, .tail = &n.head, \ + .version_head = NULL, .version_tail = &n.version_head, \ +} + struct prcu_local_struct { unsigned int locked; unsigned int online; unsigned long long version; + struct prcu_cblist cblist; }; struct prcu_struct { @@ -24,6 +45,8 @@ struct prcu_struct { void prcu_read_lock(void); void prcu_read_unlock(void); void synchronize_prcu(void); +void call_prcu(struct rcu_head *head, rcu_callback_t func); +void prcu_init(void); void prcu_note_context_switch(void); #else /* #ifdef CONFIG_PRCU */ @@ -31,6 +54,8 @@ void prcu_note_context_switch(void); #define prcu_read_lock() do {} while (0) #define prcu_read_unlock() do {} while (0) #define synchronize_prcu() do {} while (0) +#define call_prcu() do {} while (0) +#define prcu_init() do {} while (0) #define prcu_note_context_switch() do {} while (0) #endif /* #ifdef CONFIG_PRCU */ diff --git a/init/main.c b/init/main.c index f8665104..4925964e 100644 --- a/init/main.c +++ b/init/main.c @@ -38,6 +38,7 @@ #include <linux/smp.h> #include <linux/profile.h> #include <linux/rcupdate.h> +#include <linux/prcu.h> #include <linux/moduleparam.h> #include <linux/kallsyms.h> #include <linux/writeback.h> @@ -574,6 +575,7 @@ asmlinkage __visible void __init start_kernel(void) workqueue_init_early(); rcu_init(); + prcu_init(); /* Trace events are available after this */ trace_init(); diff --git a/kernel/rcu/prcu.c b/kernel/rcu/prcu.c index a00b9420..f198285c 100644 --- a/kernel/rcu/prcu.c +++ b/kernel/rcu/prcu.c @@ -1,11 +1,12 @@ #include <linux/smp.h> -#include <linux/prcu.h> #include <linux/percpu.h> -#include <linux/compiler.h> +#include <linux/prcu.h> #include <linux/sched.h> - +#include <linux/slab.h> #include <asm/barrier.h> +#include "rcu.h" + DEFINE_PER_CPU_SHARED_ALIGNED(struct prcu_local_struct, prcu_local); struct prcu_struct global_prcu = { @@ -16,6 +17,16 @@ struct prcu_struct global_prcu = { }; struct prcu_struct *prcu = &global_prcu; +/* Initialize simple callback list. */ +static void prcu_cblist_init(struct prcu_cblist *rclp) +{ + rclp->head = NULL; + rclp->tail = &rclp->head; + rclp->version_head = NULL; + rclp->version_tail = &rclp->version_head; + rclp->len = 0; +} + static inline void prcu_report(struct prcu_local_struct *local) { unsigned long long global_version; @@ -123,3 +134,53 @@ void prcu_note_context_switch(void) prcu_report(local); put_cpu_ptr(&prcu_local); } + +void call_prcu(struct rcu_head *head, rcu_callback_t func) +{ + unsigned long flags; + struct prcu_local_struct *local; + struct prcu_cblist *rclp; + struct prcu_version_head *vhp; + + debug_rcu_head_queue(head); + + /* Use GFP_ATOMIC with IRQs disabled */ + vhp = kmalloc(sizeof(struct prcu_version_head), GFP_ATOMIC); + if (!vhp) + return; + + head->func = func; + head->next = NULL; + vhp->next = NULL; + + local_irq_save(flags); + local = this_cpu_ptr(&prcu_local); + vhp->version = local->version; + rclp = &local->cblist; + rclp->len++; + *rclp->tail = head; + rclp->tail = &head->next; + *rclp->version_tail = vhp; + rclp->version_tail = &vhp->next; + local_irq_restore(flags); +} +EXPORT_SYMBOL(call_prcu); + +void prcu_init_local_struct(int cpu) +{ + struct prcu_local_struct *local; + + local = per_cpu_ptr(&prcu_local, cpu); + local->locked = 0; + local->online = 0; + local->version = 0; + prcu_cblist_init(&local->cblist); +} + +void __init prcu_init(void) +{ + int cpu; + + for_each_possible_cpu(cpu) + prcu_init_local_struct(cpu); +} -- 2.14.1.729.g59c0ea183
