The following commit has been merged into the core/rcu branch of tip: Commit-ID: fe63b723cc7ca3a91ea91274e0f2cba29452b3fa Gitweb: https://git.kernel.org/tip/fe63b723cc7ca3a91ea91274e0f2cba29452b3fa Author: Paul E. McKenney <paul...@kernel.org> AuthorDate: Tue, 23 Jun 2020 18:04:45 -07:00 Committer: Paul E. McKenney <paul...@kernel.org> CommitterDate: Mon, 24 Aug 2020 18:36:07 -07:00
rcu: Add READ_ONCE() to rcu_do_batch() access to rcu_kick_kthreads Given that sysfs can change the value of rcu_kick_kthreads at any time, this commit adds a READ_ONCE() to the sole access to that variable. Signed-off-by: Paul E. McKenney <paul...@kernel.org> --- kernel/rcu/tree_stall.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index b5d3b47..a1780a6 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -158,7 +158,7 @@ static void rcu_stall_kick_kthreads(void) { unsigned long j; - if (!rcu_kick_kthreads) + if (!READ_ONCE(rcu_kick_kthreads)) return; j = READ_ONCE(rcu_state.jiffies_kick_kthreads); if (time_after(jiffies, j) && rcu_state.gp_kthread && @@ -580,7 +580,7 @@ static void check_cpu_stall(struct rcu_data *rdp) unsigned long js; struct rcu_node *rnp; - if ((rcu_stall_is_suppressed() && !rcu_kick_kthreads) || + if ((rcu_stall_is_suppressed() && !READ_ONCE(rcu_kick_kthreads)) || !rcu_gp_in_progress()) return; rcu_stall_kick_kthreads();