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| author |   Neeraj Upadhyay <neeraju@codeaurora.org> | 2019-03-29 16:57:08 +0530 |
|---|---|---|
| committer |   Paul E. McKenney <paulmck@linux.ibm.com> | 2019-05-28 09:02:57 -0700 |
| commit | 3ae976a7e3e87438b8439a01aeb79d4866b1c444 (patch) | |
| tree | 3909fa53f6a8ea05abfd45fdbeab0423ab62523f /kernel/rcu/tree_stall.h | |
| parent | rcu: Dump specified number of blocked tasks (diff) | |
| download | linux-dev-3ae976a7e3e87438b8439a01aeb79d4866b1c444.tar.xz linux-dev-3ae976a7e3e87438b8439a01aeb79d4866b1c444.zip | |
rcu: Correctly unlock root node in rcu_check_gp_start_stall()
On systems whose rcu_node tree has only one node, the
rcu_check_gp_start_stall() function's values of rnp and rnp_root will
be identical. In this case, it clearly does not make sense to release
both rnp->lock and rnp_root->lock, but that is exactly what this function
does in the last early exit. This commit therefore unlocks only rnp->lock
when rnp and rnp_root are equal.
Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Diffstat (limited to 'kernel/rcu/tree_stall.h')
| -rw-r--r-- | kernel/rcu/tree_stall.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index f65a73a97323..065183391f75 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -630,7 +630,9 @@ static void rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp, time_before(j, rcu_state.gp_req_activity + gpssdelay) || time_before(j, rcu_state.gp_activity + gpssdelay) || atomic_xchg(&warned, 1)) { - raw_spin_unlock_rcu_node(rnp_root); /* irqs remain disabled. */ + if (rnp_root != rnp) + /* irqs remain disabled. */ + raw_spin_unlock_rcu_node(rnp_root); raw_spin_unlock_irqrestore_rcu_node(rnp, flags); return; } |