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Date:   Mon, 7 Sep 2020 08:16:19 +0100
From:   Christoph Hellwig <hch@infradead.org>
To:     Bean Huo <huobean@gmail.com>
Cc:     akpm@linux-foundation.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, beanhuo@micron.com,
        Richard Weinberger <richard@nod.at>,
        linux-mtd@lists.infradead.org
Subject: Re: [PATCH RFC] mm: Let readahead submit larger batches of pages in
 case of ra->ra_pages == 0
Message-ID: <20200907071619.GA28569@infradead.org>
References: <20200904144807.31810-1-huobean@gmail.com>
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On Fri, Sep 04, 2020 at 04:48:07PM +0200, Bean Huo wrote:
> From: Bean Huo <beanhuo@micron.com>
> 
> Current generic_file_buffered_read() will break up the larger batches of pages
> and read data in single page length in case of ra->ra_pages == 0. This patch is
> to allow it to pass the batches of pages down to the device if the supported
> maximum IO size >= the requested size.

At least ubifs and mtd seem to force ra_pages = 0 to disable read-ahead
entirely, so this seems intentional.