Linux Virtualization - Sep 2023 - [PATCH V11 07/17] riscv: qspinlock: Introduce qspinlock param for command line

On 9/10/23 04:29, guoren at kernel.org wrote:
> From: Guo Ren <guoren at linux.alibaba.com>
>
> Allow cmdline to force the kernel to use queued_spinlock when
> CONFIG_RISCV_COMBO_SPINLOCKS=y.
>
> Signed-off-by: Guo Ren <guoren at linux.alibaba.com>
> Signed-off-by: Guo Ren <guoren at kernel.org>
> ---
>   Documentation/admin-guide/kernel-parameters.txt |  2 ++
>   arch/riscv/kernel/setup.c                       | 16 +++++++++++++++-
>   2 files changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt
b/Documentation/admin-guide/kernel-parameters.txt
> index 7dfb540c4f6c..61cacb8dfd0e 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -4693,6 +4693,8 @@
>   			[KNL] Number of legacy pty's. Overwrites compiled-in
>   			default number.
>   
> +	qspinlock	[RISCV] Force to use qspinlock or auto-detect spinlock.
> +
>   	qspinlock.numa_spinlock_threshold_ns=	[NUMA, PV_OPS]
>   			Set the time threshold in nanoseconds for the
>   			number of intra-node lock hand-offs before the
> diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
> index a447cf360a18..0f084f037651 100644
> --- a/arch/riscv/kernel/setup.c
> +++ b/arch/riscv/kernel/setup.c
> @@ -270,6 +270,15 @@ static void __init parse_dtb(void)
>   }
>   
>   #ifdef CONFIG_RISCV_COMBO_SPINLOCKS
> +bool enable_qspinlock_key = false;
You can use __ro_after_init qualifier for enable_qspinlock_key. BTW, 
this is not a static key, just a simple flag. So what is the point of 
the _key suffix?

Cheers,
Longman