diff options
| author | Paul E. McKenney <paulmck@us.ibm.com> | 2005-05-01 08:59:04 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-05-01 08:59:04 -0700 |
| commit | 9b06e818985d139fd9e82c28297f7744e1b484e1 (patch) | |
| tree | 3cd2ba33b22fc2812f714f86ea52c68704f8e2c3 /kernel/rcupdate.c | |
| parent | 512345be2549308b8ae8e85a3ff7f6d56a38e5f6 (diff) | |
[PATCH] Deprecate synchronize_kernel, GPL replacement
The synchronize_kernel() primitive is used for quite a few different purposes:
waiting for RCU readers, waiting for NMIs, waiting for interrupts, and so on.
This makes RCU code harder to read, since synchronize_kernel() might or might
not have matching rcu_read_lock()s. This patch creates a new
synchronize_rcu() that is to be used for RCU readers and a new
synchronize_sched() that is used for the rest. These two new primitives
currently have the same implementation, but this is might well change with
additional real-time support. Both new primitives are GPL-only, the old
primitive is deprecated.
Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/rcupdate.c')
| -rw-r--r-- | kernel/rcupdate.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index ad497722f04f..f436993bd590 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -444,15 +444,18 @@ static void wakeme_after_rcu(struct rcu_head *head) } /** - * synchronize_kernel - wait until a grace period has elapsed. + * synchronize_rcu - wait until a grace period has elapsed. * * Control will return to the caller some time after a full grace * period has elapsed, 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. + * + * If your read-side code is not protected by rcu_read_lock(), do -not- + * use synchronize_rcu(). */ -void synchronize_kernel(void) +void synchronize_rcu(void) { struct rcu_synchronize rcu; @@ -464,7 +467,16 @@ void synchronize_kernel(void) wait_for_completion(&rcu.completion); } +/* + * Deprecated, use synchronize_rcu() or synchronize_sched() instead. + */ +void synchronize_kernel(void) +{ + synchronize_rcu(); +} + module_param(maxbatch, int, 0); EXPORT_SYMBOL(call_rcu); /* WARNING: GPL-only in April 2006. */ EXPORT_SYMBOL(call_rcu_bh); /* WARNING: GPL-only in April 2006. */ +EXPORT_SYMBOL_GPL(synchronize_rcu); EXPORT_SYMBOL(synchronize_kernel); /* WARNING: GPL-only in April 2006. */ |