Re: [PATCH 05/13] readahead: set file_ra_state->ra_pages to be at least mapping_min_order

[Matthew Wilcox]

On Mon, Feb 26, 2024 at 10:49:28AM +0100, Pankaj Raghav (Samsung) wrote:
> From: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> 
> 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.

Don't we rather want to round up to a multiple of mapping_min_nrpages?

>  file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping)
>  {
> +	unsigned int min_nrpages = mapping_min_folio_nrpages(mapping);
> +
>  	ra->ra_pages = inode_to_bdi(mapping->host)->ra_pages;
> +	if (ra->ra_pages < min_nrpages)
> +		ra->ra_pages = min_nrpages;
>  	ra->prev_pos = -1;