Re: [PATCH 1/2] rcuscale: add kfree_rcu() single-argument scale test

Uladzislau Rezki
2021-02-04T14:16:34Z

Hello, Paul.

> To stress and test a single argument of kfree_rcu() call, we
> should to have a special coverage for it. We used to have it
> in the test-suite related to vmalloc stressing. The reason is
> the rcuscale is a correct place for RCU related things.
>
> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
> ---
> kernel/rcu/rcuscale.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c
> index 06491d5530db..e17745a155f9 100644
> --- a/kernel/rcu/rcuscale.c
> +++ b/kernel/rcu/rcuscale.c
> @@ -94,6 +94,7 @@ torture_param(bool, shutdown, RCUSCALE_SHUTDOWN,
> torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
> torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
> torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() scale test?");
> +torture_param(int, kfree_rcu_test_single, 0, "Do we run a kfree_rcu() single-argument scale test?");
> torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
>
> static char *scale_type = "rcu";
> @@ -667,10 +668,14 @@ kfree_scale_thread(void *arg)
>
> for (i = 0; i < kfree_alloc_num; i++) {
> alloc_ptr = kmalloc(kfree_mult * sizeof(struct kfree_obj), GFP_KERNEL);
> +
> if (!alloc_ptr)
> return -ENOMEM;
>
> - kfree_rcu(alloc_ptr, rh);
> + if (kfree_rcu_test_single)
> + kfree_rcu(alloc_ptr);
> + else
> + kfree_rcu(alloc_ptr, rh);
> }
>
> cond_resched();
> --
> 2.20.1
>
What is about this change? Do you have any concern or comments?

--
Vlad Rezki