x86, mm: Add __get_user_pages_fast()

Introduce a gup_fast() variant which is usable from IRQ/NMI context.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Nick Piggin <npiggin@suse.de>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index ad613ed66ab0..b457bc047ab1 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -863,6 +863,12 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
                         struct page **pages);
 
 /*
+ * doesn't attempt to fault and will return short.
+ */
+int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
+                          struct page **pages);
+
+/*
  * A callback you can register to apply pressure to ageable caches.
  *
  * 'shrink' is passed a count 'nr_to_scan' and a 'gfpmask'.  It should