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-rw-r--r--Documentation/RCU/00-INDEX2
-rw-r--r--Documentation/RCU/Design/Data-Structures/Data-Structures.html26
-rw-r--r--Documentation/RCU/rculist_nulls.txt6
-rw-r--r--Documentation/RCU/whatisRCU.txt3
4 files changed, 31 insertions, 6 deletions
diff --git a/Documentation/RCU/00-INDEX b/Documentation/RCU/00-INDEX
index f773a264ae02..1672573b037a 100644
--- a/Documentation/RCU/00-INDEX
+++ b/Documentation/RCU/00-INDEX
@@ -17,7 +17,7 @@ rcu_dereference.txt
rcubarrier.txt
- RCU and Unloadable Modules
rculist_nulls.txt
- - RCU list primitives for use with SLAB_DESTROY_BY_RCU
+ - RCU list primitives for use with SLAB_TYPESAFE_BY_RCU
rcuref.txt
- Reference-count design for elements of lists/arrays protected by RCU
rcu.txt
diff --git a/Documentation/RCU/Design/Data-Structures/Data-Structures.html b/Documentation/RCU/Design/Data-Structures/Data-Structures.html
index 2ab38ee420c5..38d6d800761f 100644
--- a/Documentation/RCU/Design/Data-Structures/Data-Structures.html
+++ b/Documentation/RCU/Design/Data-Structures/Data-Structures.html
@@ -1185,6 +1185,9 @@ Its fields are as follows:
1 int dynticks_nesting;
2 int dynticks_nmi_nesting;
3 atomic_t dynticks;
+ 4 bool rcu_need_heavy_qs;
+ 5 unsigned long rcu_qs_ctr;
+ 6 bool rcu_urgent_qs;
</pre>
<p>The <tt>-&gt;dynticks_nesting</tt> field counts the
@@ -1198,11 +1201,32 @@ NMIs are counted by the <tt>-&gt;dynticks_nmi_nesting</tt>
field, except that NMIs that interrupt non-dyntick-idle execution
are not counted.
-</p><p>Finally, the <tt>-&gt;dynticks</tt> field counts the corresponding
+</p><p>The <tt>-&gt;dynticks</tt> field counts the corresponding
CPU's transitions to and from dyntick-idle mode, so that this counter
has an even value when the CPU is in dyntick-idle mode and an odd
value otherwise.
+</p><p>The <tt>-&gt;rcu_need_heavy_qs</tt> field is used
+to record the fact that the RCU core code would really like to
+see a quiescent state from the corresponding CPU, so much so that
+it is willing to call for heavy-weight dyntick-counter operations.
+This flag is checked by RCU's context-switch and <tt>cond_resched()</tt>
+code, which provide a momentary idle sojourn in response.
+
+</p><p>The <tt>-&gt;rcu_qs_ctr</tt> field is used to record
+quiescent states from <tt>cond_resched()</tt>.
+Because <tt>cond_resched()</tt> can execute quite frequently, this
+must be quite lightweight, as in a non-atomic increment of this
+per-CPU field.
+
+</p><p>Finally, the <tt>-&gt;rcu_urgent_qs</tt> field is used to record
+the fact that the RCU core code would really like to see a quiescent
+state from the corresponding CPU, with the various other fields indicating
+just how badly RCU wants this quiescent state.
+This flag is checked by RCU's context-switch and <tt>cond_resched()</tt>
+code, which, if nothing else, non-atomically increment <tt>-&gt;rcu_qs_ctr</tt>
+in response.
+
<table>
<tr><th>&nbsp;</th></tr>
<tr><th align="left">Quick Quiz:</th></tr>
diff --git a/Documentation/RCU/rculist_nulls.txt b/Documentation/RCU/rculist_nulls.txt
index 18f9651ff23d..8151f0195f76 100644
--- a/Documentation/RCU/rculist_nulls.txt
+++ b/Documentation/RCU/rculist_nulls.txt
@@ -1,5 +1,5 @@
Using hlist_nulls to protect read-mostly linked lists and
-objects using SLAB_DESTROY_BY_RCU allocations.
+objects using SLAB_TYPESAFE_BY_RCU allocations.
Please read the basics in Documentation/RCU/listRCU.txt
@@ -7,7 +7,7 @@ Using special makers (called 'nulls') is a convenient way
to solve following problem :
A typical RCU linked list managing objects which are
-allocated with SLAB_DESTROY_BY_RCU kmem_cache can
+allocated with SLAB_TYPESAFE_BY_RCU kmem_cache can
use following algos :
1) Lookup algo
@@ -96,7 +96,7 @@ unlock_chain(); // typically a spin_unlock()
3) Remove algo
--------------
Nothing special here, we can use a standard RCU hlist deletion.
-But thanks to SLAB_DESTROY_BY_RCU, beware a deleted object can be reused
+But thanks to SLAB_TYPESAFE_BY_RCU, beware a deleted object can be reused
very very fast (before the end of RCU grace period)
if (put_last_reference_on(obj) {
diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt
index 8c131a1c62ea..8ed6c9f6133c 100644
--- a/Documentation/RCU/whatisRCU.txt
+++ b/Documentation/RCU/whatisRCU.txt
@@ -928,7 +928,8 @@ d. Do you need RCU grace periods to complete even in the face
e. Is your workload too update-intensive for normal use of
RCU, but inappropriate for other synchronization mechanisms?
- If so, consider SLAB_DESTROY_BY_RCU. But please be careful!
+ If so, consider SLAB_TYPESAFE_BY_RCU (which was originally
+ named SLAB_DESTROY_BY_RCU). But please be careful!
f. Do you need read-side critical sections that are respected
even though they are in the middle of the idle loop, during