Re: [PATCH] locking/csd-lock: make CSD lock debug tunables writable in /sys

[Paul E. McKenney]

On Mon, Dec 09, 2024 at 12:44:11PM -0500, Rik van Riel wrote:
> Currently the CSD lock tunables can only be set at boot time in the
> kernel commandline, but the way these variables are used means there
> is really no reason not to tune them at runtime through /sys.
> 
> Make the CSD lock debug tunables tunable through /sys.
> 
> Signed-off-by: Rik van Riel <riel@xxxxxxxxxxx>

Good point, and queued for v6.14 merge window.

Unless someone else would prefer to carry it, in which case:

Reviewed-by: Paul E. McKenney <paulmck@xxxxxxxxxx>

> ---
>  kernel/smp.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/smp.c b/kernel/smp.c
> index 27dc31a146a3..a33e575f97ab 100644
> --- a/kernel/smp.c
> +++ b/kernel/smp.c
> @@ -170,9 +170,9 @@ static DEFINE_PER_CPU(smp_call_func_t, cur_csd_func);
>  static DEFINE_PER_CPU(void *, cur_csd_info);
>  
>  static ulong csd_lock_timeout = 5000;  /* CSD lock timeout in milliseconds. */
> -module_param(csd_lock_timeout, ulong, 0444);
> +module_param(csd_lock_timeout, ulong, 0644);
>  static int panic_on_ipistall;  /* CSD panic timeout in milliseconds, 300000 for five minutes. */
> -module_param(panic_on_ipistall, int, 0444);
> +module_param(panic_on_ipistall, int, 0644);
>  
>  static atomic_t csd_bug_count = ATOMIC_INIT(0);
>  
> -- 
> 2.47.0
>