From 65e423f8ee5843e1ea3f2d94adf4ba3560a17f7b Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 19 May 2010 10:42:16 -0700 Subject: Update documentation to note the passage of INIT_RCU_HEAD() Signed-off-by: Alexey Dobriyan Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- Documentation/DocBook/kernel-locking.tmpl | 8 -------- 1 file changed, 8 deletions(-) (limited to 'Documentation/DocBook') diff --git a/Documentation/DocBook/kernel-locking.tmpl b/Documentation/DocBook/kernel-locking.tmpl index 084f6ad7b7a0..e6cc57460212 100644 --- a/Documentation/DocBook/kernel-locking.tmpl +++ b/Documentation/DocBook/kernel-locking.tmpl @@ -1725,14 +1725,6 @@ the amount of locking which needs to be done. if (++cache_num > MAX_CACHE_SIZE) { struct object *i, *outcast = NULL; list_for_each_entry(i, &cache, list) { -@@ -85,6 +94,7 @@ - obj->popularity = 0; - atomic_set(&obj->refcnt, 1); /* The cache holds a reference */ - spin_lock_init(&obj->lock); -+ INIT_RCU_HEAD(&obj->rcu); - - spin_lock_irqsave(&cache_lock, flags); - __cache_add(obj); @@ -104,12 +114,11 @@ struct object *cache_find(int id) { -- cgit v1.2.3 From ded5e5ed2f3348ba2f9a319c6497e46c22850e97 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 19 May 2010 10:46:55 -0700 Subject: Update call_rcu() usage, add synchronize_rcu() Reported-by: Kyle Hubert Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- Documentation/DocBook/kernel-locking.tmpl | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'Documentation/DocBook') diff --git a/Documentation/DocBook/kernel-locking.tmpl b/Documentation/DocBook/kernel-locking.tmpl index e6cc57460212..ed64d220baf2 100644 --- a/Documentation/DocBook/kernel-locking.tmpl +++ b/Documentation/DocBook/kernel-locking.tmpl @@ -1645,7 +1645,9 @@ the amount of locking which needs to be done. all the readers who were traversing the list when we deleted the element are finished. We use call_rcu() to register a callback which will actually destroy the object once - the readers are finished. + all pre-existing readers are finished. Alternatively, + synchronize_rcu() may be used to block until + all pre-existing are finished. But how does Read Copy Update know when the readers are @@ -1714,7 +1716,7 @@ the amount of locking which needs to be done. - object_put(obj); + list_del_rcu(&obj->list); cache_num--; -+ call_rcu(&obj->rcu, cache_delete_rcu, obj); ++ call_rcu(&obj->rcu, cache_delete_rcu); } /* Must be holding cache_lock */ -- cgit v1.2.3