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Date: Mon, 26 Feb 2024 14:49:04 +0000
From: Matthew Wilcox <willy@infradead.org>
To: "Pankaj Raghav (Samsung)" <kernel@pankajraghav.com>
Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, david@fromorbit.com,
	chandan.babu@oracle.com, akpm@linux-foundation.org,
	mcgrof@kernel.org, ziy@nvidia.com, hare@suse.de, djwong@kernel.org,
	gost.dev@samsung.com, linux-mm@kvack.org,
	Pankaj Raghav <p.raghav@samsung.com>
Subject: Re: [PATCH 05/13] readahead: set file_ra_state->ra_pages to be at
 least mapping_min_order
Message-ID: <Zdyk4ErGQHc1q-1W@casper.infradead.org>
References: <20240226094936.2677493-1-kernel@pankajraghav.com>
 <20240226094936.2677493-6-kernel@pankajraghav.com>
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On Mon, Feb 26, 2024 at 10:49:28AM +0100, 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.

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;