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authorPaul E. McKenney <paul.mckenney@linaro.org>2012-01-05 14:44:39 -0800
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2012-02-21 09:03:24 -0800
commit0bb7b59d6e2b8440cd7097097dd4bbfc4d76ed07 (patch)
treef0f36a0a5b6ea4ffd1a43e0c7bb5e90803076746
parentfe15d706cfc1cb321dbe2329b04b5ca185edff60 (diff)
downloadlinux-rt-0bb7b59d6e2b8440cd7097097dd4bbfc4d76ed07.tar.gz
rcu: Add diagnostic for misaligned rcu_head structures
The push for energy efficiency will require that RCU tag rcu_head structures to indicate whether or not their invocation is time critical. This tagging is best carried out in the bottom bits of the ->next pointers in the rcu_head structures. This tagging requires that the rcu_head structures be properly aligned, so this commit adds the required diagnostics. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
-rw-r--r--kernel/rcutree.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 3cf713a724c1..570f7530f4b3 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1707,6 +1707,7 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu),
unsigned long flags;
struct rcu_data *rdp;
+ WARN_ON_ONCE((unsigned long)head & 0x3); /* Misaligned rcu_head! */
debug_rcu_head_queue(head);
head->func = func;
head->next = NULL;