Subject: Re: [PATCH] powerpc: warn users of smt-snooze-delay that the API isn't there anymore

From: Madhavan Srinivasan <[email-masked]>
Date: Tue, 25 Feb 2014 10:23:58 +0530

On Saturday 22 February 2014 05:44 AM, Cody P Schafer wrote:
> /sys/devices/system/cpu/cpu*/smt-snooze-delay was converted into a NOP
> in commit 3fa8cad82b94d0bed002571bd246f2299ffc876b, and now does
> nothing. Add a pr_warn() to convince any users that they should stop
> using it.
> 
> The commit message from the removing commit notes that this
> functionality should move into the cpuidle driver, essentially by

Would prefer to cleanup the code since the functionality is moved,
instead of adding to it.

> adjusting target_residency to the specified value. At the moment,
> target_residency is not exposed by cpuidle's sysfs, so there isn't a
> drop in replacement for this.
> 
> Signed-off-by: Cody P Schafer <[email-masked]>
> ---
>  arch/powerpc/kernel/sysfs.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
> index 97e1dc9..84097b4 100644
> --- a/arch/powerpc/kernel/sysfs.c
> +++ b/arch/powerpc/kernel/sysfs.c
> @@ -50,6 +50,9 @@ static ssize_t store_smt_snooze_delay(struct device *dev,
>  	if (ret != 1)
>  		return -EINVAL;
>  
> +	pr_warn_ratelimited("%s (%d): /sys/devices/system/cpu/cpu%d/smt-snooze-delay is deprecated and is a NOP\n",
> +		  current->comm, task_pid_nr(current), cpu->dev.id);
> +
>  	per_cpu(smt_snooze_delay, cpu->dev.id) = snooze;
>  	return count;
>  }
> @@ -60,6 +63,9 @@ static ssize_t show_smt_snooze_delay(struct device *dev,
>  {
>  	struct cpu *cpu = container_of(dev, struct cpu, dev);
>  
> +	pr_warn_ratelimited("%s (%d): /sys/devices/system/cpu/cpu%d/smt-snooze-delay is deprecated and is a NOP\n",
> +		  current->comm, task_pid_nr(current), cpu->dev.id);
> +
>  	return sprintf(buf, "%ld\n", per_cpu(smt_snooze_delay, cpu->dev.id));
>  }
>  
>