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authorLinus Torvalds <torvalds@linux-foundation.org>2010-10-21 12:54:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-21 12:54:12 -0700
commit888a6f77e0418b049f83d37547c209b904d30af4 (patch)
tree42cdb9f781d2177e6b380e69a66a27ec7705f51f /Documentation/DocBook/kernel-locking.tmpl
parent31b7eab27a314b153d8fa07ba9e9ec00a98141e1 (diff)
parent6506cf6ce68d78a5470a8360c965dafe8e4b78e3 (diff)
downloadop-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.tmpl14
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(&amp;obj-&gt;list);
cache_num--;
-+ call_rcu(&amp;obj-&gt;rcu, cache_delete_rcu, obj);
++ call_rcu(&amp;obj-&gt;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, &amp;cache, list) {
-@@ -85,6 +94,7 @@
- obj-&gt;popularity = 0;
- atomic_set(&amp;obj-&gt;refcnt, 1); /* The cache holds a reference */
- spin_lock_init(&amp;obj-&gt;lock);
-+ INIT_RCU_HEAD(&amp;obj-&gt;rcu);
-
- spin_lock_irqsave(&amp;cache_lock, flags);
- __cache_add(obj);
@@ -104,12 +114,11 @@
struct object *cache_find(int id)
{
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