Re: [PATCH 01/25] fs/buffer: Convert to hotplug state machine

[Al Viro]

On Thu, Nov 03, 2016 at 03:49:57PM +0100, Sebastian Andrzej Siewior wrote:
> Install the callbacks via the state machine.

> diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
> index afe641c02dca..69b74fa0da60 100644
> --- a/include/linux/cpuhotplug.h
> +++ b/include/linux/cpuhotplug.h
> @@ -30,6 +30,7 @@ enum cpuhp_state {
>  	CPUHP_ACPI_CPUDRV_DEAD,
>  	CPUHP_S390_PFAULT_DEAD,
>  	CPUHP_BLK_MQ_DEAD,
> +	CPUHP_FS_BUFF_DEAD,
>  	CPUHP_WORKQUEUE_PREP,
>  	CPUHP_POWER_NUMA_PREPARE,
>  	CPUHP_HRTIMERS_PREPARE,

*ouch*

So we are getting a large list of things from unrelated subsystems, maintained
in a single place, all next to each other.  All examples of that sort of
thing I can recall had ended up biting our arses...