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

[Uladzislau Rezki <urezki@gmail.com>]

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