Re: [PATCH v5 2/4] mm: Provide kernel parameter to allow disabling page init poisoning

[Michal Hocko]

On Tue 25-09-18 13:20:12, Alexander Duyck wrote:
[...]
> +	vm_debug[=options]	[KNL] Available with CONFIG_DEBUG_VM=y.
> +			May slow down system boot speed, especially when
> +			enabled on systems with a large amount of memory.
> +			All options are enabled by default, and this
> +			interface is meant to allow for selectively
> +			enabling or disabling specific virtual memory
> +			debugging features.
> +
> +			Available options are:
> +			  P	Enable page structure init time poisoning
> +			  -	Disable all of the above options

I agree with Dave that this is confusing as hell. So what does vm_debug
(without any options means). I assume it's NOP and all debugging is
enabled and that is the default. What if I want to disable _only_ the
page struct poisoning. The weird lookcing `-' will disable all other
options that we might gather in the future.

Why cannot you simply go with [no]vm_page_poison[=on/off]?
-- 
Michal Hocko
SUSE Labs