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| author | Timur Tabi <timur@freescale.com> | 2008-07-23 21:28:11 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-24 10:47:20 -0700 |
| commit | 2be0ffe2b29bd31d3debd0877797892ff2d91f4c (patch) | |
| tree | 7f6e56b3fc5a721296851448e3facf821ef543dd /include/linux/gfp.h | |
| parent | 3560e249abda6bee41a07a7bf0383a6e193e2839 (diff) | |
| download | lwn-2be0ffe2b29bd31d3debd0877797892ff2d91f4c.tar.gz lwn-2be0ffe2b29bd31d3debd0877797892ff2d91f4c.zip | |
mm: add alloc_pages_exact() and free_pages_exact()
alloc_pages_exact() is similar to alloc_pages(), except that it allocates
the minimum number of pages to fulfill the request. This is useful if you
want to allocate a very large buffer that is slightly larger than an even
power-of-two number of pages. In that case, alloc_pages() will waste a
lot of memory.
I have a video driver that wants to allocate a 5MB buffer. alloc_pages()
wiill waste 3MB of physically-contiguous memory.
Signed-off-by: Timur Tabi <timur@freescale.com>
Cc: Andi Kleen <andi@firstfloor.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/gfp.h')
| -rw-r--r-- | include/linux/gfp.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/gfp.h b/include/linux/gfp.h index f640ed241422..e8003afeffba 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -228,6 +228,9 @@ extern struct page *alloc_page_vma(gfp_t gfp_mask, extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order); extern unsigned long get_zeroed_page(gfp_t gfp_mask); +void *alloc_pages_exact(size_t size, gfp_t gfp_mask); +void free_pages_exact(void *virt, size_t size); + #define __get_free_page(gfp_mask) \ __get_free_pages((gfp_mask),0) |