On Wed, Apr 14, 2021 at 03:24:13PM +0200, Frederic Weisbecker wrote:
> Test an early call to start_poll_synchronize_srcu() and place it before
> the early test to call_srcu() on the same ssp.
>
> After the later call to srcu_barrier(), we expect the first grace period
> completion to be visible by a subsequent call to
> poll_state_synchronize_srcu(). Report otherwise.
>
> Signed-off-by: Frederic Weisbecker <frede...@kernel.org>
Given the first patch, this one looks good, give or take my usual
editing compulsion.
Thanx, Paul
> Cc: Boqun Feng <boqun.f...@gmail.com>
> Cc: Lai Jiangshan <jiangshan...@gmail.com>
> Cc: Neeraj Upadhyay <neer...@codeaurora.org>
> Cc: Josh Triplett <j...@joshtriplett.org>
> Cc: Joel Fernandes <j...@joelfernandes.org>
> Cc: Uladzislau Rezki <ure...@gmail.com>
> ---
> kernel/rcu/update.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
> index dd94a602a6d2..c21b38cc25e9 100644
> --- a/kernel/rcu/update.c
> +++ b/kernel/rcu/update.c
> @@ -524,6 +524,7 @@ static void test_callback(struct rcu_head *r)
> }
>
> DEFINE_STATIC_SRCU(early_srcu);
> +static unsigned long early_srcu_cookie;
>
> struct early_boot_kfree_rcu {
> struct rcu_head rh;
> @@ -536,8 +537,10 @@ static void early_boot_test_call_rcu(void)
> struct early_boot_kfree_rcu *rhp;
>
> call_rcu(&head, test_callback);
> - if (IS_ENABLED(CONFIG_SRCU))
> + if (IS_ENABLED(CONFIG_SRCU)) {
> + early_srcu_cookie = start_poll_synchronize_srcu(&early_srcu);
> call_srcu(&early_srcu, &shead, test_callback);
> + }
> rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
> if (!WARN_ON_ONCE(!rhp))
> kfree_rcu(rhp, rh);
> @@ -563,6 +566,7 @@ static int rcu_verify_early_boot_tests(void)
> if (IS_ENABLED(CONFIG_SRCU)) {
> early_boot_test_counter++;
> srcu_barrier(&early_srcu);
> + WARN_ON_ONCE(!poll_state_synchronize_srcu(&early_srcu,
> early_srcu_cookie));
> }
> }
> if (rcu_self_test_counter != early_boot_test_counter) {
> --
> 2.25.1
>
