Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / Documentation / RCU / listRCU.txt

diff --git a/Documentation/RCU/listRCU.txt b/Documentation/RCU/listRCU.txt
index f8a54fa..1fd1753 100644 (file)
--- a/Documentation/RCU/listRCU.txt
+++ b/Documentation/RCU/listRCU.txt
@@ -232,7 +232,7 @@ entry does not exist.  For this to be helpful, the search function must
 return holding the per-entry spinlock, as ipc_lock() does in fact do.
 
 Quick Quiz:  Why does the search function need to return holding the
-per-entry lock for this deleted-flag technique to be helpful?
+       per-entry lock for this deleted-flag technique to be helpful?
 
 If the system-call audit module were to ever need to reject stale data,
 one way to accomplish this would be to add a "deleted" flag and a "lock"
@@ -275,8 +275,8 @@ flag under the spinlock as follows:
        {
                struct audit_entry  *e;
 
-               /* Do not use the _rcu iterator here, since this is the only
-                * deletion routine. */
+               /* Do not need to use the _rcu iterator here, since this
+                * is the only deletion routine. */
                list_for_each_entry(e, list, list) {
                        if (!audit_compare_rule(rule, &e->rule)) {
                                spin_lock(&e->lock);
@@ -304,9 +304,12 @@ function to reject newly deleted data.
 
 
 Answer to Quick Quiz
-
-If the search function drops the per-entry lock before returning, then
-the caller will be processing stale data in any case.  If it is really
-OK to be processing stale data, then you don't need a "deleted" flag.
-If processing stale data really is a problem, then you need to hold the
-per-entry lock across all of the code that uses the value looked up.
+       Why does the search function need to return holding the per-entry
+       lock for this deleted-flag technique to be helpful?
+
+       If the search function drops the per-entry lock before returning,
+       then the caller will be processing stale data in any case.  If it
+       is really OK to be processing stale data, then you don't need a
+       "deleted" flag.  If processing stale data really is a problem,
+       then you need to hold the per-entry lock across all of the code
+       that uses the value that was returned.