path: root/mm/mempolicy.c
diff options
authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2010-03-03 17:50:17 -0800
committerIngo Molnar <mingo@elte.hu>2010-03-04 12:07:34 +0100
commit99ee4ca746dda71326db7645463b4075ac1d665c (patch)
treeffee1bb0da458f7067a3207df0507be98dea7764 /mm/mempolicy.c
parente6033e3b307fcfae08408e0673266db38392bda4 (diff)
rcu: Suppress __mpol_dup() false positive from RCU lockdep
Common code is used during task creation and after the task has started running. RCU protection is not needed during task creation because no other CPU has access to the under-construction task. Provide the RCU protection anyway to suppress the false positive, as there does not appear to be a good way for the common code to recognize that the task is only accessible to the CPU creating it. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1267667418-32233-2-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'mm/mempolicy.c')
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 290fb5bf044..3cec080faa2 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1730,10 +1730,12 @@ struct mempolicy *__mpol_dup(struct mempolicy *old)
if (!new)
return ERR_PTR(-ENOMEM);
+ rcu_read_lock();
if (current_cpuset_is_being_rebound()) {
nodemask_t mems = cpuset_mems_allowed(current);
mpol_rebind_policy(old, &mems);
+ rcu_read_unlock();
*new = *old;
atomic_set(&new->refcnt, 1);
return new;