Re: [PATCH 2/2] posix_fadvise.2: Document the behaviour of partial page discard requests

["Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>]

On 12/03/2014 01:42 AM, Mel Gorman wrote:
> It is not obvious from the interface that partial page discard requests
> are ignored. It should be spelled out.

Thanks, Mel. Applied.

Cheers,

Michael


> Signed-off-by: Mel Gorman <mgorman@suse.de>
> ---
>  man2/posix_fadvise.2 | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/man2/posix_fadvise.2 b/man2/posix_fadvise.2
> index 25d0c50..07313a9 100644
> --- a/man2/posix_fadvise.2
> +++ b/man2/posix_fadvise.2
> @@ -144,6 +144,11 @@ A program may periodically request the kernel to free cached data
>  that has already been used, so that more useful cached pages are not
>  discarded instead.
>  
> +Requests to discard partial pages are ignored. It is preferable to preserve
> +needed data than discard unneeded data. If the application requires that
> +data be considered for discarding then \fIoffset\fP and \fIlen\fP must be
> +page-aligned.
> +
>  Pages that have not yet been written out will be unaffected, so if the
>  application wishes to guarantee that pages will be released, it should
>  call
> 


-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/

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