[tip: core/rcu] scftorture: Adapt memory-ordering test to UP operation

[tip-bot2 for Paul E. McKenney]

The following commit has been merged into the core/rcu branch of tip:

Commit-ID:     9e66bf03f9c538863e614a72c5799bcd9579630e
Gitweb:        https://git.kernel.org/tip/9e66bf03f9c538863e614a72c5799bcd9579630e
Author:        Paul E. McKenney <paulmck@xxxxxxxxxx>
AuthorDate:    Fri, 03 Jul 2020 15:23:19 -07:00
Committer:     Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Mon, 24 Aug 2020 18:38:37 -07:00

scftorture: Adapt memory-ordering test to UP operation

On uniprocessor systems, smp_call_function() does nothing.  This commit
therefore avoids complaining about the lack of handler accesses in the
single-CPU case where there is no handler.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
 kernel/scftorture.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/scftorture.c b/kernel/scftorture.c
index 04d3a42..fc22bcc 100644
--- a/kernel/scftorture.c
+++ b/kernel/scftorture.c
@@ -363,7 +363,8 @@ static void scftorture_invoke_one(struct scf_statistics *scfp, struct torture_ra
 			scfcp->scfc_out = true;
 	}
 	if (scfcp && scfsp->scfs_wait) {
-		if (WARN_ON_ONCE(!scfcp->scfc_out))
+		if (WARN_ON_ONCE((num_online_cpus() > 1 || scfsp->scfs_prim == SCF_PRIM_SINGLE) &&
+				 !scfcp->scfc_out))
 			atomic_inc(&n_mb_out_errs); // Leak rather than trash!
 		else
 			kfree(scfcp);