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author | David S. Miller <davem@davemloft.net> | 2009-04-16 17:35:26 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2009-04-16 17:35:26 -0700 |
commit | a54bfa40fd16aeb90bc556189221576f746f8567 (patch) | |
tree | 176bb7a99ffab5f42f0dd4e9671f335be3f3efa0 /arch/x86/mm/gup.c | |
parent | fe957c40ec5e2763b9977c565beab3bde3aaf85b (diff) | |
parent | 134ffb4cad92a6aa534e55a9be145bca780a32c1 (diff) |
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Diffstat (limited to 'arch/x86/mm/gup.c')
-rw-r--r-- | arch/x86/mm/gup.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c index be54176e9eb..6340cef6798 100644 --- a/arch/x86/mm/gup.c +++ b/arch/x86/mm/gup.c @@ -219,6 +219,22 @@ static int gup_pud_range(pgd_t pgd, unsigned long addr, unsigned long end, return 1; } +/** + * get_user_pages_fast() - pin user pages in memory + * @start: starting user address + * @nr_pages: number of pages from start to pin + * @write: whether pages will be written to + * @pages: array that receives pointers to the pages pinned. + * Should be at least nr_pages long. + * + * Attempt to pin user pages in memory without taking mm->mmap_sem. + * If not successful, it will fall back to taking the lock and + * calling get_user_pages(). + * + * Returns number of pages pinned. This may be fewer than the number + * requested. If nr_pages is 0 or negative, returns 0. If no pages + * were pinned, returns -errno. + */ int get_user_pages_fast(unsigned long start, int nr_pages, int write, struct page **pages) { |