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authorLinus Torvalds <torvalds@linux-foundation.org>2011-05-20 05:14:34 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2011-05-20 05:14:34 +0400
commiteb04f2f04ed1227c266b3219c0aaeda525639718 (patch)
tree7f224483a3cd0e439cd64a8666ec9dc5ed178a3d /kernel/rcupdate.c
parent5765040ebfc9a28d9dcfaaaaf3d25840d922de96 (diff)
parent80d02085d99039b3b7f3a73c8896226b0cb1ba07 (diff)
downloadlinux-eb04f2f04ed1227c266b3219c0aaeda525639718.tar.xz
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: (78 commits) Revert "rcu: Decrease memory-barrier usage based on semi-formal proof" net,rcu: convert call_rcu(prl_entry_destroy_rcu) to kfree batman,rcu: convert call_rcu(softif_neigh_free_rcu) to kfree_rcu batman,rcu: convert call_rcu(neigh_node_free_rcu) to kfree() batman,rcu: convert call_rcu(gw_node_free_rcu) to kfree_rcu net,rcu: convert call_rcu(kfree_tid_tx) to kfree_rcu() net,rcu: convert call_rcu(xt_osf_finger_free_rcu) to kfree_rcu() net/mac80211,rcu: convert call_rcu(work_free_rcu) to kfree_rcu() net,rcu: convert call_rcu(wq_free_rcu) to kfree_rcu() net,rcu: convert call_rcu(phonet_device_rcu_free) to kfree_rcu() perf,rcu: convert call_rcu(swevent_hlist_release_rcu) to kfree_rcu() perf,rcu: convert call_rcu(free_ctx) to kfree_rcu() net,rcu: convert call_rcu(__nf_ct_ext_free_rcu) to kfree_rcu() net,rcu: convert call_rcu(net_generic_release) to kfree_rcu() net,rcu: convert call_rcu(netlbl_unlhsh_free_addr6) to kfree_rcu() net,rcu: convert call_rcu(netlbl_unlhsh_free_addr4) to kfree_rcu() security,rcu: convert call_rcu(sel_netif_free) to kfree_rcu() net,rcu: convert call_rcu(xps_dev_maps_release) to kfree_rcu() net,rcu: convert call_rcu(xps_map_release) to kfree_rcu() net,rcu: convert call_rcu(rps_map_release) to kfree_rcu() ...
Diffstat (limited to 'kernel/rcupdate.c')
-rw-r--r--kernel/rcupdate.c32
1 files changed, 24 insertions, 8 deletions
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index f3240e987928..7784bd216b6a 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -142,10 +142,17 @@ static int rcuhead_fixup_init(void *addr, enum debug_obj_state state)
* Ensure that queued callbacks are all executed.
* If we detect that we are nested in a RCU read-side critical
* section, we should simply fail, otherwise we would deadlock.
+ * In !PREEMPT configurations, there is no way to tell if we are
+ * in a RCU read-side critical section or not, so we never
+ * attempt any fixup and just print a warning.
*/
+#ifndef CONFIG_PREEMPT
+ WARN_ON_ONCE(1);
+ return 0;
+#endif
if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
irqs_disabled()) {
- WARN_ON(1);
+ WARN_ON_ONCE(1);
return 0;
}
rcu_barrier();
@@ -184,10 +191,17 @@ static int rcuhead_fixup_activate(void *addr, enum debug_obj_state state)
* Ensure that queued callbacks are all executed.
* If we detect that we are nested in a RCU read-side critical
* section, we should simply fail, otherwise we would deadlock.
+ * In !PREEMPT configurations, there is no way to tell if we are
+ * in a RCU read-side critical section or not, so we never
+ * attempt any fixup and just print a warning.
*/
+#ifndef CONFIG_PREEMPT
+ WARN_ON_ONCE(1);
+ return 0;
+#endif
if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
irqs_disabled()) {
- WARN_ON(1);
+ WARN_ON_ONCE(1);
return 0;
}
rcu_barrier();
@@ -214,15 +228,17 @@ static int rcuhead_fixup_free(void *addr, enum debug_obj_state state)
* Ensure that queued callbacks are all executed.
* If we detect that we are nested in a RCU read-side critical
* section, we should simply fail, otherwise we would deadlock.
- * Note that the machinery to reliably determine whether
- * or not we are in an RCU read-side critical section
- * exists only in the preemptible RCU implementations
- * (TINY_PREEMPT_RCU and TREE_PREEMPT_RCU), which is why
- * DEBUG_OBJECTS_RCU_HEAD is disallowed if !PREEMPT.
+ * In !PREEMPT configurations, there is no way to tell if we are
+ * in a RCU read-side critical section or not, so we never
+ * attempt any fixup and just print a warning.
*/
+#ifndef CONFIG_PREEMPT
+ WARN_ON_ONCE(1);
+ return 0;
+#endif
if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
irqs_disabled()) {
- WARN_ON(1);
+ WARN_ON_ONCE(1);
return 0;
}
rcu_barrier();