Re: [PATCH] thermal: intel: powerclamp: Fix cpumask and max_idle module parameters
From: srinivas pandruvada
Date: Thu Mar 30 2023 - 13:36:42 EST
On Thu, 2023-03-30 at 09:42 -0400, David Arcari wrote:
Reviewed-by: Srinivas Pandruvada <>> When cpumask is specified as a module parameter the value is
> overwritten by the module init routine. This can easily be fixed
> by checking to see if the mask has already been allocated in the
> init routine.
>
> When max_idle is specified as a module parameter a panic will occur.
> The problem is that the idle_injection_cpu_mask is not allocated
> until
> the module init routine executes. This can easily be fixed by
> allocating
> the cpumask if it's not already allocated.
>
> Fixes: ebf519710218 ("thermal: intel: powerclamp: Add two module
> parameters")
>
> Signed-off-by: David Arcari <darcari@xxxxxxxxxx>
Reviewed-by: Srinivas Pandruvada<srinivas.pandruvada@xxxxxxxxxxxxxxx>
>
> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
> Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> Cc: Amit Kucheria <amitk@xxxxxxxxxx>
> Cc: Zhang Rui <rui.zhang@xxxxxxxxx>
> Cc: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
> Cc: David Arcari <darcari@xxxxxxxxxx>
> Cc: Chen Yu <yu.c.chen@xxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: stable@xxxxxxxxxxxxxxx
>
> ---
> drivers/thermal/intel/intel_powerclamp.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/thermal/intel/intel_powerclamp.c
> b/drivers/thermal/intel/intel_powerclamp.c
> index c7ba5680cd48..91fc7e239497 100644
> --- a/drivers/thermal/intel/intel_powerclamp.c
> +++ b/drivers/thermal/intel/intel_powerclamp.c
> @@ -235,6 +235,12 @@ static int max_idle_set(const char *arg, const
> struct kernel_param *kp)
> goto skip_limit_set;
> }
>
> + if (!cpumask_available(idle_injection_cpu_mask)) {
> + ret =
> allocate_copy_idle_injection_mask(cpu_present_mask);
> + if (ret)
> + goto skip_limit_set;
> + }
> +
> if (check_invalid(idle_injection_cpu_mask, new_max_idle)) {
> ret = -EINVAL;
> goto skip_limit_set;
> @@ -791,7 +797,8 @@ static int __init powerclamp_init(void)
> return retval;
>
> mutex_lock(&powerclamp_lock);
> - retval = allocate_copy_idle_injection_mask(cpu_present_mask);
> + if (!cpumask_available(idle_injection_cpu_mask))
> + retval =
> allocate_copy_idle_injection_mask(cpu_present_mask);
> mutex_unlock(&powerclamp_lock);
>
> if (retval)