From: "Paul E. McKenney" paulmck@kernel.org
[ Upstream commit 11377947b5861fa59bf77c827e1dd7c081842cc9 ]
Currently, if the rcuscale module's async module parameter is specified for RCU implementations that do not have async primitives such as RCU Tasks Rude (which now lacks a call_rcu_tasks_rude() function), there will be a series of splats due to calls to a NULL pointer. This commit therefore warns of this situation, but switches to non-async testing.
Signed-off-by: "Paul E. McKenney" paulmck@kernel.org Signed-off-by: Neeraj Upadhyay neeraj.upadhyay@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/rcu/rcuscale.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c index 8db4fedaaa1eb..a5806baa1a2a8 100644 --- a/kernel/rcu/rcuscale.c +++ b/kernel/rcu/rcuscale.c @@ -498,7 +498,7 @@ rcu_scale_writer(void *arg) schedule_timeout_idle(torture_random(&tr) % writer_holdoff_jiffies + 1); wdp = &wdpp[i]; *wdp = ktime_get_mono_fast_ns(); - if (gp_async) { + if (gp_async && !WARN_ON_ONCE(!cur_ops->async)) { retry: if (!rhp) rhp = kmalloc(sizeof(*rhp), GFP_KERNEL); @@ -554,7 +554,7 @@ rcu_scale_writer(void *arg) i++; rcu_scale_wait_shutdown(); } while (!torture_must_stop()); - if (gp_async) { + if (gp_async && cur_ops->async) { cur_ops->gp_barrier(); } writer_n_durations[me] = i_max + 1;