Messages in this thread Patch in this message | | | From | Lai Jiangshan <> | Subject | [PATCH] rcu_tree: avoid touch rnp->completed when starts a new GP | Date | Tue, 13 Jan 2015 15:30:34 +0800 |
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In rcu_gp_init(), rnp->completed equals to rsp->completed in THEORY, we don't need to touch it normally. If something goes wrong, it will complain and fixup rnp->completed and avoid oops.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> --- kernel/rcu/tree.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 7680fc2..ea6dc28 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1639,8 +1639,8 @@ static int rcu_gp_init(struct rcu_state *rsp) rcu_preempt_check_blocked_tasks(rnp); rnp->qsmask = rnp->qsmaskinit; ACCESS_ONCE(rnp->gpnum) = rsp->gpnum; - WARN_ON_ONCE(rnp->completed != rsp->completed); - ACCESS_ONCE(rnp->completed) = rsp->completed; + if (WARN_ON_ONCE(rnp->completed != rsp->completed)) + ACCESS_ONCE(rnp->completed) = rsp->completed; if (rnp == rdp->mynode) (void)__note_gp_changes(rsp, rnp, rdp); rcu_preempt_boost_start_gp(rnp); -- 2.1.0
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