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author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-21 12:54:12 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-21 12:54:12 -0700 |
commit | 888a6f77e0418b049f83d37547c209b904d30af4 (patch) | |
tree | 42cdb9f781d2177e6b380e69a66a27ec7705f51f /Documentation/DocBook/kernel-locking.tmpl | |
parent | 31b7eab27a314b153d8fa07ba9e9ec00a98141e1 (diff) | |
parent | 6506cf6ce68d78a5470a8360c965dafe8e4b78e3 (diff) | |
download | op-kernel-dev-888a6f77e0418b049f83d37547c209b904d30af4.zip op-kernel-dev-888a6f77e0418b049f83d37547c209b904d30af4.tar.gz |
Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (52 commits)
sched: fix RCU lockdep splat from task_group()
rcu: using ACCESS_ONCE() to observe the jiffies_stall/rnp->qsmask value
sched: suppress RCU lockdep splat in task_fork_fair
net: suppress RCU lockdep false positive in sock_update_classid
rcu: move check from rcu_dereference_bh to rcu_read_lock_bh_held
rcu: Add advice to PROVE_RCU_REPEATEDLY kernel config parameter
rcu: Add tracing data to support queueing models
rcu: fix sparse errors in rcutorture.c
rcu: only one evaluation of arg in rcu_dereference_check() unless sparse
kernel: Remove undead ifdef CONFIG_DEBUG_LOCK_ALLOC
rcu: fix _oddness handling of verbose stall warnings
rcu: performance fixes to TINY_PREEMPT_RCU callback checking
rcu: upgrade stallwarn.txt documentation for CPU-bound RT processes
vhost: add __rcu annotations
rcu: add comment stating that list_empty() applies to RCU-protected lists
rcu: apply TINY_PREEMPT_RCU read-side speedup to TREE_PREEMPT_RCU
rcu: combine duplicate code, courtesy of CONFIG_PREEMPT_RCU
rcu: Upgrade srcu_read_lock() docbook about SRCU grace periods
rcu: document ways of stalling updates in low-memory situations
rcu: repair code-duplication FIXMEs
...
Diffstat (limited to 'Documentation/DocBook/kernel-locking.tmpl')
-rw-r--r-- | Documentation/DocBook/kernel-locking.tmpl | 14 |
1 files changed, 4 insertions, 10 deletions
diff --git a/Documentation/DocBook/kernel-locking.tmpl b/Documentation/DocBook/kernel-locking.tmpl index a0d479d..f66f4df 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 <function>call_rcu()</function> to register a callback which will actually destroy the object once - the readers are finished. + all pre-existing readers are finished. Alternatively, + <function>synchronize_rcu()</function> may be used to block until + all pre-existing are finished. </para> <para> 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 */ @@ -1725,14 +1727,6 @@ 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) { |