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Date: Wed, 21 Mar 2007 00:34:08 +0300
From: "Dan Kruchinin" <dubalom@gmail.com>
To: "Chris Friesen" <cfriesen@nortel.com>, linux-kernel@vger.kernel.org
Subject: Re: how to purposfully fragment memory?
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On 3/20/07, Chris Friesen <cfriesen@nortel.com> wrote:
> Asgard wrote:
>
> > btw, can you describe your aim in details?
>
> I'm doing some work on a network device driver.  We were having jumbo
> frame issues after being up for a month or so because it couldn't
> allocate enough contiguous memory.
>
> We've got a new code path now that doesn't need large contiguous
> allocations, so I'd like to demonstrate it by forcing the system to
> become severely fragmented.
>
> Chris
>

and by the way, you can try to use void split_page(struct page *page,
unsigned int order) function, but keep in mind, that it's not
recommended to use it in drivers:
/*
 * split_page takes a non-compound higher-order page, and splits it into
 * n (1<<order) sub-pages: page[0..n]
 * Each sub-page must be freed individually.
 *
 * Note: this is probably too low level an operation for use in drivers.
 * Please consult with lkml before using this in your driver.
 */
void split_page(struct page *page, unsigned int order)

Good luck.
Dan.