diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/rcuclassic.h | 161 | ||||
| -rw-r--r-- | include/linux/rcupdate.h | 168 |
2 files changed, 210 insertions, 119 deletions
diff --git a/include/linux/rcuclassic.h b/include/linux/rcuclassic.h new file mode 100644 index 000000000000..2b8b045a51d5 --- /dev/null +++ b/include/linux/rcuclassic.h @@ -0,0 +1,161 @@ +/* + * Read-Copy Update mechanism for mutual exclusion (classic version) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * Copyright IBM Corporation, 2001 + * + * Author: Dipankar Sarma <dipankar@in.ibm.com> + * + * Based on the original work by Paul McKenney <paulmck@us.ibm.com> + * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. + * Papers: + * http://www.rdrop.com/users/paulmck/paper/rclockpdcsproof.pdf + * http://lse.sourceforge.net/locking/rclock_OLS.2001.05.01c.sc.pdf (OLS2001) + * + * For detailed explanation of Read-Copy Update mechanism see - + * Documentation/RCU + * + */ + +#ifndef __LINUX_RCUCLASSIC_H +#define __LINUX_RCUCLASSIC_H + +#ifdef __KERNEL__ + +#include <linux/cache.h> +#include <linux/spinlock.h> +#include <linux/threads.h> +#include <linux/percpu.h> +#include <linux/cpumask.h> +#include <linux/seqlock.h> + + +/* Global control variables for rcupdate callback mechanism. */ +struct rcu_ctrlblk { + long cur; /* Current batch number. */ + long completed; /* Number of the last completed batch */ + int next_pending; /* Is the next batch already waiting? */ + + int signaled; + + spinlock_t lock ____cacheline_internodealigned_in_smp; + cpumask_t cpumask; /* CPUs that need to switch in order */ + /* for current batch to proceed. */ +} ____cacheline_internodealigned_in_smp; + +/* Is batch a before batch b ? */ +static inline int rcu_batch_before(long a, long b) +{ + return (a - b) < 0; +} + +/* Is batch a after batch b ? */ +static inline int rcu_batch_after(long a, long b) +{ + return (a - b) > 0; +} + +/* + * Per-CPU data for Read-Copy UPdate. + * nxtlist - new callbacks are added here + * curlist - current batch for which quiescent cycle started if any + */ +struct rcu_data { + /* 1) quiescent state handling : */ + long quiescbatch; /* Batch # for grace period */ + int passed_quiesc; /* User-mode/idle loop etc. */ + int qs_pending; /* core waits for quiesc state */ + + /* 2) batch handling */ + long batch; /* Batch # for current RCU batch */ + struct rcu_head *nxtlist; + struct rcu_head **nxttail; + long qlen; /* # of queued callbacks */ + struct rcu_head *curlist; + struct rcu_head **curtail; + struct rcu_head *donelist; + struct rcu_head **donetail; + long blimit; /* Upper limit on a processed batch */ + int cpu; + struct rcu_head barrier; +}; + +DECLARE_PER_CPU(struct rcu_data, rcu_data); +DECLARE_PER_CPU(struct rcu_data, rcu_bh_data); + +/* + * Increment the quiescent state counter. + * The counter is a bit degenerated: We do not need to know + * how many quiescent states passed, just if there was at least + * one since the start of the grace period. Thus just a flag. + */ +static inline void rcu_qsctr_inc(int cpu) +{ + struct rcu_data *rdp = &per_cpu(rcu_data, cpu); + rdp->passed_quiesc = 1; +} +static inline void rcu_bh_qsctr_inc(int cpu) +{ + struct rcu_data *rdp = &per_cpu(rcu_bh_data, cpu); + rdp->passed_quiesc = 1; +} + +extern int rcu_pending(int cpu); +extern int rcu_needs_cpu(int cpu); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +extern struct lockdep_map rcu_lock_map; +# define rcu_read_acquire() \ + lock_acquire(&rcu_lock_map, 0, 0, 2, 1, _THIS_IP_) +# define rcu_read_release() lock_release(&rcu_lock_map, 1, _THIS_IP_) +#else +# define rcu_read_acquire() do { } while (0) +# define rcu_read_release() do { } while (0) +#endif + +#define __rcu_read_lock() \ + do { \ + preempt_disable(); \ + __acquire(RCU); \ + rcu_read_acquire(); \ + } while (0) +#define __rcu_read_unlock() \ + do { \ + rcu_read_release(); \ + __release(RCU); \ + preempt_enable(); \ + } while (0) +#define __rcu_read_lock_bh() \ + do { \ + local_bh_disable(); \ + __acquire(RCU_BH); \ + rcu_read_acquire(); \ + } while (0) +#define __rcu_read_unlock_bh() \ + do { \ + rcu_read_release(); \ + __release(RCU_BH); \ + local_bh_enable(); \ + } while (0) + +#define __synchronize_sched() synchronize_rcu() + +extern void __rcu_init(void); +extern void rcu_check_callbacks(int cpu, int user); +extern void rcu_restart_cpu(int cpu); + +#endif /* __KERNEL__ */ +#endif /* __LINUX_RCUCLASSIC_H */ diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index cc24a01df940..12aa13e13150 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -15,7 +15,7 @@ * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * - * Copyright (C) IBM Corporation, 2001 + * Copyright IBM Corporation, 2001 * * Author: Dipankar Sarma <dipankar@in.ibm.com> * @@ -53,96 +53,14 @@ struct rcu_head { void (*func)(struct rcu_head *head); }; +#include <linux/rcuclassic.h> + #define RCU_HEAD_INIT { .next = NULL, .func = NULL } #define RCU_HEAD(head) struct rcu_head head = RCU_HEAD_INIT #define INIT_RCU_HEAD(ptr) do { \ (ptr)->next = NULL; (ptr)->func = NULL; \ } while (0) - - -/* Global control variables for rcupdate callback mechanism. */ -struct rcu_ctrlblk { - long cur; /* Current batch number. */ - long completed; /* Number of the last completed batch */ - int next_pending; /* Is the next batch already waiting? */ - - int signaled; - - spinlock_t lock ____cacheline_internodealigned_in_smp; - cpumask_t cpumask; /* CPUs that need to switch in order */ - /* for current batch to proceed. */ -} ____cacheline_internodealigned_in_smp; - -/* Is batch a before batch b ? */ -static inline int rcu_batch_before(long a, long b) -{ - return (a - b) < 0; -} - -/* Is batch a after batch b ? */ -static inline int rcu_batch_after(long a, long b) -{ - return (a - b) > 0; -} - -/* - * Per-CPU data for Read-Copy UPdate. - * nxtlist - new callbacks are added here - * curlist - current batch for which quiescent cycle started if any - */ -struct rcu_data { - /* 1) quiescent state handling : */ - long quiescbatch; /* Batch # for grace period */ - int passed_quiesc; /* User-mode/idle loop etc. */ - int qs_pending; /* core waits for quiesc state */ - - /* 2) batch handling */ - long batch; /* Batch # for current RCU batch */ - struct rcu_head *nxtlist; - struct rcu_head **nxttail; - long qlen; /* # of queued callbacks */ - struct rcu_head *curlist; - struct rcu_head **curtail; - struct rcu_head *donelist; - struct rcu_head **donetail; - long blimit; /* Upper limit on a processed batch */ - int cpu; - struct rcu_head barrier; -}; - -DECLARE_PER_CPU(struct rcu_data, rcu_data); -DECLARE_PER_CPU(struct rcu_data, rcu_bh_data); - -/* - * Increment the quiescent state counter. - * The counter is a bit degenerated: We do not need to know - * how many quiescent states passed, just if there was at least - * one since the start of the grace period. Thus just a flag. - */ -static inline void rcu_qsctr_inc(int cpu) -{ - struct rcu_data *rdp = &per_cpu(rcu_data, cpu); - rdp->passed_quiesc = 1; -} -static inline void rcu_bh_qsctr_inc(int cpu) -{ - struct rcu_data *rdp = &per_cpu(rcu_bh_data, cpu); - rdp->passed_quiesc = 1; -} - -extern int rcu_pending(int cpu); -extern int rcu_needs_cpu(int cpu); - -#ifdef CONFIG_DEBUG_LOCK_ALLOC -extern struct lockdep_map rcu_lock_map; -# define rcu_read_acquire() lock_acquire(&rcu_lock_map, 0, 0, 2, 1, _THIS_IP_) -# define rcu_read_release() lock_release(&rcu_lock_map, 1, _THIS_IP_) -#else -# define rcu_read_acquire() do { } while (0) -# define rcu_read_release() do { } while (0) -#endif - /** * rcu_read_lock - mark the beginning of an RCU read-side critical section. * @@ -172,24 +90,13 @@ extern struct lockdep_map rcu_lock_map; * * It is illegal to block while in an RCU read-side critical section. */ -#define rcu_read_lock() \ - do { \ - preempt_disable(); \ - __acquire(RCU); \ - rcu_read_acquire(); \ - } while(0) +#define rcu_read_lock() __rcu_read_lock() /** * rcu_read_unlock - marks the end of an RCU read-side critical section. * * See rcu_read_lock() for more information. */ -#define rcu_read_unlock() \ - do { \ - rcu_read_release(); \ - __release(RCU); \ - preempt_enable(); \ - } while(0) /* * So where is rcu_write_lock()? It does not exist, as there is no @@ -200,6 +107,7 @@ extern struct lockdep_map rcu_lock_map; * used as well. RCU does not care how the writers keep out of each * others' way, as long as they do so. */ +#define rcu_read_unlock() __rcu_read_unlock() /** * rcu_read_lock_bh - mark the beginning of a softirq-only RCU critical section @@ -212,24 +120,14 @@ extern struct lockdep_map rcu_lock_map; * can use just rcu_read_lock(). * */ -#define rcu_read_lock_bh() \ - do { \ - local_bh_disable(); \ - __acquire(RCU_BH); \ - rcu_read_acquire(); \ - } while(0) +#define rcu_read_lock_bh() __rcu_read_lock_bh() /* * rcu_read_unlock_bh - marks the end of a softirq-only RCU critical section * * See rcu_read_lock_bh() for more information. */ -#define rcu_read_unlock_bh() \ - do { \ - rcu_read_release(); \ - __release(RCU_BH); \ - local_bh_enable(); \ - } while(0) +#define rcu_read_unlock_bh() __rcu_read_unlock_bh() /* * Prevent the compiler from merging or refetching accesses. The compiler @@ -293,21 +191,53 @@ extern struct lockdep_map rcu_lock_map; * In "classic RCU", these two guarantees happen to be one and * the same, but can differ in realtime RCU implementations. */ -#define synchronize_sched() synchronize_rcu() +#define synchronize_sched() __synchronize_sched() + +/** + * call_rcu - Queue an RCU callback for invocation after a grace period. + * @head: structure to be used for queueing the RCU updates. + * @func: actual update function to be invoked after the grace period + * + * The update function will be invoked some time after a full grace + * period elapses, in other words after all currently executing RCU + * read-side critical sections have completed. RCU read-side critical + * sections are delimited by rcu_read_lock() and rcu_read_unlock(), + * and may be nested. + */ +extern void call_rcu(struct rcu_head *head, + void (*func)(struct rcu_head *head)); + +/** + * call_rcu_bh - Queue an RCU for invocation after a quicker grace period. + * @head: structure to be used for queueing the RCU updates. + * @func: actual update function to be invoked after the grace period + * + * The update function will be invoked some time after a full grace + * period elapses, in other words after all currently executing RCU + * read-side critical sections have completed. call_rcu_bh() assumes + * that the read-side critical sections end on completion of a softirq + * handler. This means that read-side critical sections in process + * context must not be interrupted by softirqs. This interface is to be + * used when most of the read-side critical sections are in softirq context. + * RCU read-side critical sections are delimited by : + * - rcu_read_lock() and rcu_read_unlock(), if in interrupt context. + * OR + * - rcu_read_lock_bh() and rcu_read_unlock_bh(), if in process context. + * These may be nested. + */ +extern void call_rcu_bh(struct rcu_head *head, + void (*func)(struct rcu_head *head)); + +/* Exported common interfaces */ +extern void synchronize_rcu(void); +extern void rcu_barrier(void); +/* Internal to kernel */ extern void rcu_init(void); extern void rcu_check_callbacks(int cpu, int user); -extern void rcu_restart_cpu(int cpu); + extern long rcu_batches_completed(void); extern long rcu_batches_completed_bh(void); -/* Exported interfaces */ -extern void FASTCALL(call_rcu(struct rcu_head *head, - void (*func)(struct rcu_head *head))); -extern void FASTCALL(call_rcu_bh(struct rcu_head *head, - void (*func)(struct rcu_head *head))); -extern void synchronize_rcu(void); -extern void rcu_barrier(void); - #endif /* __KERNEL__ */ #endif /* __LINUX_RCUPDATE_H */ |