Re: [PATCH] docs: fault-injection: fix defaults

[Jonathan Corbet <corbet@lwn.net>]

Dylan Yudaken <dylany@fb.com> writes:

> ignore-gfp-wait and ignore-gfp-highmem defaults are actually true (Y) in
> both failslab and fail_page_alloc, not false as the docs suggest. See
> page_alloc.c:3762 and failslab.c:13
>
> At the same time use 'Y' instead of '1' in the example scripts just for
> consistency. (though 1 would work)
>
> Signed-off-by: Dylan Yudaken <dylany@fb.com>
> ---
>  Documentation/fault-injection/fault-injection.rst | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/fault-injection/fault-injection.rst b/Documentation/fault-injection/fault-injection.rst
> index 4a25c5eb6f07..8b4e1ce26d01 100644
> --- a/Documentation/fault-injection/fault-injection.rst
> +++ b/Documentation/fault-injection/fault-injection.rst
> @@ -132,7 +132,7 @@ configuration of fault-injection capabilities.
>  
>  	Format: { 'Y' | 'N' }
>  
> -	default is 'N', setting it to 'Y' won't inject failures into
> +	default is 'Y', setting it to 'Y' won't inject failures into
>  	highmem/user allocations.

So the associated help text should perhaps have its sense changed too -
what happens if you set it to "N"?  The help text would be more useful,
IMO, if it read something like "set to 'N' if you want errors injected
into GFP_HIGHUSER allocations" (or whatever GFP flags actually apply
here). 

>  - /sys/kernel/debug/failslab/ignore-gfp-wait:
> @@ -140,7 +140,7 @@ configuration of fault-injection capabilities.
>  
>  	Format: { 'Y' | 'N' }
>  
> -	default is 'N', setting it to 'Y' will inject failures
> +	default is 'Y', setting it to 'Y' will inject failures
>  	only into non-sleep allocations (GFP_ATOMIC allocations).

This is a little better in general, but still would be improved by
telling the reader what they get if they change the default.

Thanks,

jon