Re: [RFC v2 04/14] readahead: set file_ra_state->ra_pages to be at least mapping_min_order

[Hannes Reinecke <hare@suse.de>]

On 2/13/24 10:37, Pankaj Raghav (Samsung) wrote:
> From: Luis Chamberlain <mcgrof@kernel.org>
> 
> Set the file_ra_state->ra_pages in file_ra_state_init() to be at least
> mapping_min_order of pages if the bdi->ra_pages is less than that.
> 
> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
> ---
>   mm/readahead.c | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/mm/readahead.c b/mm/readahead.c
> index 2648ec4f0494..4fa7d0e65706 100644
> --- a/mm/readahead.c
> +++ b/mm/readahead.c
> @@ -138,7 +138,12 @@
>   void
>   file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping)
>   {
> +	unsigned int min_nrpages = mapping_min_folio_nrpages(mapping);
> +	unsigned int max_pages = inode_to_bdi(mapping->host)->io_pages;
> +
>   	ra->ra_pages = inode_to_bdi(mapping->host)->ra_pages;
> +	if (ra->ra_pages < min_nrpages && min_nrpages < max_pages)
> +		ra->ra_pages = min_nrpages;
>   	ra->prev_pos = -1;
>   }
>   EXPORT_SYMBOL_GPL(file_ra_state_init);

Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes