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@surriel.com>
---
 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

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@surriel.com>

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@kernel.org>

> ---
>  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
>