Commit f9411ebe authored by Ingo Molnar's avatar Ingo Molnar

rcu: Separate the RCU synchronization types and APIs into <linux/rcupdate_wait.h>

So rcupdate.h is a pretty complex header, in particular it includes
<linux/completion.h> which includes <linux/wait.h> - creating a
dependency that includes <linux/wait.h> in <linux/sched.h>,
which prevents the isolation of <linux/sched.h> from the derived
<linux/wait.h> header.

Solve part of the problem by decoupling rcupdate.h from completions:
this can be done by separating out the rcu_synchronize types and APIs,
and updating their usage sites.

Since this is a mostly RCU-internal types this will not just simplify
<linux/sched.h>'s dependencies, but will make all the hundreds of
.c files that include rcupdate.h but not completions or wait.h build
faster.

( For rcutiny this means that two dependent APIs have to be uninlined,
  but that shouldn't be much of a problem as they are rare variants. )
Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 4b53a341
......@@ -14,6 +14,7 @@
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/completion.h>
/* This is the range of ioctl() numbers we claim as ours */
#define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
......
......@@ -11,6 +11,7 @@
#include <linux/rcupdate.h>
#include <linux/lockref.h>
#include <linux/stringhash.h>
#include <linux/wait.h>
struct path;
struct vfsmount;
......
......@@ -40,7 +40,6 @@
#include <linux/cpumask.h>
#include <linux/seqlock.h>
#include <linux/lockdep.h>
#include <linux/completion.h>
#include <linux/debugobjects.h>
#include <linux/bug.h>
#include <linux/compiler.h>
......@@ -226,45 +225,6 @@ void call_rcu_sched(struct rcu_head *head,
void synchronize_sched(void);
/*
* Structure allowing asynchronous waiting on RCU.
*/
struct rcu_synchronize {
struct rcu_head head;
struct completion completion;
};
void wakeme_after_rcu(struct rcu_head *head);
void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array,
struct rcu_synchronize *rs_array);
#define _wait_rcu_gp(checktiny, ...) \
do { \
call_rcu_func_t __crcu_array[] = { __VA_ARGS__ }; \
struct rcu_synchronize __rs_array[ARRAY_SIZE(__crcu_array)]; \
__wait_rcu_gp(checktiny, ARRAY_SIZE(__crcu_array), \
__crcu_array, __rs_array); \
} while (0)
#define wait_rcu_gp(...) _wait_rcu_gp(false, __VA_ARGS__)
/**
* synchronize_rcu_mult - Wait concurrently for multiple grace periods
* @...: List of call_rcu() functions for the flavors to wait on.
*
* This macro waits concurrently for multiple flavors of RCU grace periods.
* For example, synchronize_rcu_mult(call_rcu, call_rcu_bh) would wait
* on concurrent RCU and RCU-bh grace periods. Waiting on a give SRCU
* domain requires you to write a wrapper function for that SRCU domain's
* call_srcu() function, supplying the corresponding srcu_struct.
*
* If Tiny RCU, tell _wait_rcu_gp() not to bother waiting for RCU
* or RCU-bh, given that anywhere synchronize_rcu_mult() can be called
* is automatically a grace period.
*/
#define synchronize_rcu_mult(...) \
_wait_rcu_gp(IS_ENABLED(CONFIG_TINY_RCU), __VA_ARGS__)
/**
* call_rcu_tasks() - Queue an RCU for invocation task-based grace period
* @head: structure to be used for queueing the RCU updates.
......
#ifndef _LINUX_SCHED_RCUPDATE_WAIT_H
#define _LINUX_SCHED_RCUPDATE_WAIT_H
/*
* RCU synchronization types and methods:
*/
#include <linux/rcupdate.h>
#include <linux/completion.h>
/*
* Structure allowing asynchronous waiting on RCU.
*/
struct rcu_synchronize {
struct rcu_head head;
struct completion completion;
};
void wakeme_after_rcu(struct rcu_head *head);
void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array,
struct rcu_synchronize *rs_array);
#define _wait_rcu_gp(checktiny, ...) \
do { \
call_rcu_func_t __crcu_array[] = { __VA_ARGS__ }; \
struct rcu_synchronize __rs_array[ARRAY_SIZE(__crcu_array)]; \
__wait_rcu_gp(checktiny, ARRAY_SIZE(__crcu_array), \
__crcu_array, __rs_array); \
} while (0)
#define wait_rcu_gp(...) _wait_rcu_gp(false, __VA_ARGS__)
/**
* synchronize_rcu_mult - Wait concurrently for multiple grace periods
* @...: List of call_rcu() functions for the flavors to wait on.
*
* This macro waits concurrently for multiple flavors of RCU grace periods.
* For example, synchronize_rcu_mult(call_rcu, call_rcu_bh) would wait
* on concurrent RCU and RCU-bh grace periods. Waiting on a give SRCU
* domain requires you to write a wrapper function for that SRCU domain's
* call_srcu() function, supplying the corresponding srcu_struct.
*
* If Tiny RCU, tell _wait_rcu_gp() not to bother waiting for RCU
* or RCU-bh, given that anywhere synchronize_rcu_mult() can be called
* is automatically a grace period.
*/
#define synchronize_rcu_mult(...) \
_wait_rcu_gp(IS_ENABLED(CONFIG_TINY_RCU), __VA_ARGS__)
#endif /* _LINUX_SCHED_RCUPDATE_WAIT_H */
......@@ -53,15 +53,8 @@ static inline void cond_synchronize_sched(unsigned long oldstate)
might_sleep();
}
static inline void rcu_barrier_bh(void)
{
wait_rcu_gp(call_rcu_bh);
}
static inline void rcu_barrier_sched(void)
{
wait_rcu_gp(call_rcu_sched);
}
extern void rcu_barrier_bh(void);
extern void rcu_barrier_sched(void);
static inline void synchronize_rcu_expedited(void)
{
......
......@@ -30,7 +30,7 @@
#include <linux/mutex.h>
#include <linux/percpu.h>
#include <linux/preempt.h>
#include <linux/rcupdate.h>
#include <linux/rcupdate_wait.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/delay.h>
......
......@@ -25,7 +25,7 @@
#include <linux/completion.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/rcupdate.h>
#include <linux/rcupdate_wait.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/mutex.h>
......@@ -47,6 +47,18 @@ static void __call_rcu(struct rcu_head *head,
#include "tiny_plugin.h"
void rcu_barrier_bh(void)
{
wait_rcu_gp(call_rcu_bh);
}
EXPORT_SYMBOL(rcu_barrier_bh);
void rcu_barrier_sched(void)
{
wait_rcu_gp(call_rcu_sched);
}
EXPORT_SYMBOL(rcu_barrier_sched);
#if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE)
/*
......
......@@ -32,7 +32,7 @@
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/smp.h>
#include <linux/rcupdate.h>
#include <linux/rcupdate_wait.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/nmi.h>
......
......@@ -49,6 +49,7 @@
#include <linux/moduleparam.h>
#include <linux/kthread.h>
#include <linux/tick.h>
#include <linux/rcupdate_wait.h>
#define CREATE_TRACE_POINTS
......
......@@ -10,6 +10,7 @@
#include <linux/delayacct.h>
#include <linux/init_task.h>
#include <linux/context_tracking.h>
#include <linux/rcupdate_wait.h>
#include <linux/blkdev.h>
#include <linux/kprobes.h>
......
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