From: "Liam R. Howlett" <howlett@gmail.com>

Faster machines may not see the initial or updated value in the race
condition.  Reduce the delay so that faster machines are less likely to
fail testing of the race conditions.

Signed-off-by: Liam R. Howlett <howlett@gmail.com>
---
 tools/testing/radix-tree/maple.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/tools/testing/radix-tree/maple.c b/tools/testing/radix-tree/maple.c
index 8b97aac1084e9..6a5b0342941c4 100644
--- a/tools/testing/radix-tree/maple.c
+++ b/tools/testing/radix-tree/maple.c
@@ -35062,7 +35062,7 @@ void run_check_rcu_slowread(struct maple_tree *mt, struct rcu_test_struct *vals)
 
 	int i;
 	void *(*function)(void *);
-	pthread_t readers[20];
+	pthread_t readers[30];
 	unsigned int index = vals->index;
 
 	mt_set_in_rcu(mt);
@@ -35080,14 +35080,14 @@ void run_check_rcu_slowread(struct maple_tree *mt, struct rcu_test_struct *vals)
 		}
 	}
 
-	usleep(5); /* small yield to ensure all threads are at least started. */
+	usleep(3); /* small yield to ensure all threads are at least started. */
 
 	while (index <= vals->last) {
 		mtree_store(mt, index,
 			    (index % 2 ? vals->entry2 : vals->entry3),
 			    GFP_KERNEL);
 		index++;
-		usleep(5);
+		usleep(2);
 	}
 
 	while (i--)
@@ -35098,6 +35098,7 @@ void run_check_rcu_slowread(struct maple_tree *mt, struct rcu_test_struct *vals)
 	MT_BUG_ON(mt, !vals->seen_entry3);
 	MT_BUG_ON(mt, !vals->seen_both);
 }
+
 static noinline void __init check_rcu_simulated(struct maple_tree *mt)
 {
 	unsigned long i, nr_entries = 1000;
-- 
2.47.2

On Mon, Jun 16, 2025 at 02:45:19PM -0400, Liam R. Howlett wrote:
> From: "Liam R. Howlett" <howlett@gmail.com>
>
> Faster machines may not see the initial or updated value in the race
> condition.  Reduce the delay so that faster machines are less likely to
> fail testing of the race conditions.
>
> Signed-off-by: Liam R. Howlett <howlett@gmail.com>

Seems reasonable so:

Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

> ---
>  tools/testing/radix-tree/maple.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/tools/testing/radix-tree/maple.c b/tools/testing/radix-tree/maple.c
> index 8b97aac1084e9..6a5b0342941c4 100644
> --- a/tools/testing/radix-tree/maple.c
> +++ b/tools/testing/radix-tree/maple.c
> @@ -35062,7 +35062,7 @@ void run_check_rcu_slowread(struct maple_tree *mt, struct rcu_test_struct *vals)
>
>  	int i;
>  	void *(*function)(void *);
> -	pthread_t readers[20];
> +	pthread_t readers[30];
>  	unsigned int index = vals->index;
>
>  	mt_set_in_rcu(mt);
> @@ -35080,14 +35080,14 @@ void run_check_rcu_slowread(struct maple_tree *mt, struct rcu_test_struct *vals)
>  		}
>  	}
>
> -	usleep(5); /* small yield to ensure all threads are at least started. */
> +	usleep(3); /* small yield to ensure all threads are at least started. */
>
>  	while (index <= vals->last) {
>  		mtree_store(mt, index,
>  			    (index % 2 ? vals->entry2 : vals->entry3),
>  			    GFP_KERNEL);
>  		index++;
> -		usleep(5);
> +		usleep(2);

Just one question... have you considered hibernation at all?

>  	}
>
>  	while (i--)
> @@ -35098,6 +35098,7 @@ void run_check_rcu_slowread(struct maple_tree *mt, struct rcu_test_struct *vals)
>  	MT_BUG_ON(mt, !vals->seen_entry3);
>  	MT_BUG_ON(mt, !vals->seen_both);
>  }
> +
>  static noinline void __init check_rcu_simulated(struct maple_tree *mt)
>  {
>  	unsigned long i, nr_entries = 1000;
> --
> 2.47.2
>