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| author | Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> | 2011-12-13 00:40:34 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-12-21 13:04:54 -0800 |
| commit | 1872856ac3ed878ec621a02573cff56491d9f410 (patch) | |
| tree | 7b4fa87defeaf38aa9f1d47ea0b56afc0384b08e /mm | |
| parent | 34456bfafc2743a19eb148d56502f9a8c0dc6fcc (diff) | |
| download | lwn-1872856ac3ed878ec621a02573cff56491d9f410.tar.gz lwn-1872856ac3ed878ec621a02573cff56491d9f410.zip | |
export __get_user_pages_fast() function
commit 45888a0c6edc305495b6bd72a30e66bc40b324c6 upstream.
Backport for stable kernel v2.6.32.y to v2.6.36.y.
Needed for next patch:
oprofile, x86: Fix nmi-unsafe callgraph support
This function is used by KVM to pin process's page in the atomic context.
Define the 'weak' function to avoid other architecture not support it
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/util.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/mm/util.c b/mm/util.c index b377ce430803..e48b493d40f8 100644 --- a/mm/util.c +++ b/mm/util.c @@ -233,6 +233,19 @@ void arch_pick_mmap_layout(struct mm_struct *mm) } #endif +/* + * Like get_user_pages_fast() except its IRQ-safe in that it won't fall + * back to the regular GUP. + * If the architecture not support this fucntion, simply return with no + * page pinned + */ +int __attribute__((weak)) __get_user_pages_fast(unsigned long start, + int nr_pages, int write, struct page **pages) +{ + return 0; +} +EXPORT_SYMBOL_GPL(__get_user_pages_fast); + /** * get_user_pages_fast() - pin user pages in memory * @start: starting user address |