2022-11-10 08:02:55

by Zqiang

Subject: [PATCH] srcu: Release early_srcu resources when no longer in use

When the "rcupdate.rcu_self_test = 1" is set in bootargs and CONFIG_SRCU
option is enabled, the early_srcu will be tested, currently, for TREE SRCU,
if "srcutree.convert_to_big = 1" is set, the srcu_node structure will be
allocated at invoke init_srcu_struct_fields() time, after the test is
completed, the early_srcu will not be used.
Therefore, this commit invoke cleanup_srcu_struct() to release srcu_node
structure.

Signed-off-by: Zqiang <[email protected]>
---
kernel/rcu/update.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index 738842c4886b..a05e23648c6b 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -589,6 +589,7 @@ static int rcu_verify_early_boot_tests(void)
early_boot_test_counter++;
srcu_barrier(&early_srcu);
WARN_ON_ONCE(!poll_state_synchronize_srcu(&early_srcu, early_srcu_cookie));
+ cleanup_srcu_struct(&early_srcu);
}
}
if (rcu_self_test_counter != early_boot_test_counter) {
--
2.25.1

2022-11-11 08:12:21

by Paul E. McKenney

Subject: Re: [PATCH] srcu: Release early_srcu resources when no longer in use

On Thu, Nov 10, 2022 at 03:30:13PM +0800, Zqiang wrote:
> When the "rcupdate.rcu_self_test = 1" is set in bootargs and CONFIG_SRCU
> option is enabled, the early_srcu will be tested, currently, for TREE SRCU,
> if "srcutree.convert_to_big = 1" is set, the srcu_node structure will be
> allocated at invoke init_srcu_struct_fields() time, after the test is
> completed, the early_srcu will not be used.
> Therefore, this commit invoke cleanup_srcu_struct() to release srcu_node
> structure.
>
> Signed-off-by: Zqiang <[email protected]>

Queued for further review and testing, thank you!

Also with the usual wordsmithing, so please check.

Thanx, Paul

> ---
> kernel/rcu/update.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
> index 738842c4886b..a05e23648c6b 100644
> --- a/kernel/rcu/update.c
> +++ b/kernel/rcu/update.c
> @@ -589,6 +589,7 @@ static int rcu_verify_early_boot_tests(void)
> early_boot_test_counter++;
> srcu_barrier(&early_srcu);
> WARN_ON_ONCE(!poll_state_synchronize_srcu(&early_srcu, early_srcu_cookie));
> + cleanup_srcu_struct(&early_srcu);
> }
> }
> if (rcu_self_test_counter != early_boot_test_counter) {
> --
> 2.25.1
>