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authorTimur Tabi <timur@freescale.com>2008-07-24 08:28:11 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-24 21:47:20 +0400
commit2be0ffe2b29bd31d3debd0877797892ff2d91f4c (patch)
tree7f6e56b3fc5a721296851448e3facf821ef543dd /include/linux/gfp.h
parent3560e249abda6bee41a07a7bf0383a6e193e2839 (diff)
downloadlinux-2be0ffe2b29bd31d3debd0877797892ff2d91f4c.tar.xz
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.h3
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)