[PATCH 05/05] mm GFP_ATOMIC comment

Paul Jackson
2005-11-14T04:04:15Z

Clarify in comments that GFP_ATOMIC means both "don't sleep"
and "use emergency pools", hence both ALLOC_DIP_ALOT and
ALLOC_DIP_SOME.

Signed-off-by: Paul Jackson <pj@sgi.com>

---

include/linux/gfp.h | 1 +
mm/page_alloc.c | 3 ++-
2 files changed, 3 insertions(+), 1 deletion(-)

--- 2.6.14-mm2.orig/include/linux/gfp.h 2005-11-13 09:57:03.317369370 -0800
+++ 2.6.14-mm2/include/linux/gfp.h 2005-11-13 10:31:05.590802684 -0800
@@ -58,6 +58,7 @@ struct vm_area_struct;
__GFP_NOFAIL|__GFP_NORETRY|__GFP_NO_GROW|__GFP_COMP| \
__GFP_NOMEMALLOC|__GFP_HARDWALL)

+/* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
#define GFP_ATOMIC (__GFP_VALID | __GFP_HIGH)
#define GFP_NOIO (__GFP_VALID | __GFP_WAIT)
#define GFP_NOFS (__GFP_VALID | __GFP_WAIT | __GFP_IO)
--- 2.6.14-mm2.orig/mm/page_alloc.c 2005-11-13 10:21:13.804965981 -0800
+++ 2.6.14-mm2/mm/page_alloc.c 2005-11-13 10:32:33.090792563 -0800
@@ -926,7 +926,8 @@ restart:
*
* The caller may dip into page reserves a bit more if the caller
* cannot run direct reclaim, or if the caller has realtime scheduling
- * policy or is asking for __GFP_HIGH memory.
+ * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
+ * set both ALLOC_DIP_ALOT (!wait) and ALLOC_DIP_SOME (__GFP_HIGH).
*/
alloc_flags = 0;
if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait)

--
I won't rest till it's the best ...
Programmer, Linux Scalability
Paul Jackson <pj@sgi.com> 1.650.933.1373