PF_MEM_NOWAIT - will make allocations fail before blocking. This is usefull
to convert process behaviour to non-blocking.

Signed-off-by: Peter Zijlstra <[EMAIL PROTECTED]>
CC: Mike Christie <[EMAIL PROTECTED]>
---
 include/linux/sched.h |    1 +
 mm/page_alloc.c       |    4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

Index: linux-2.6/include/linux/sched.h
===================================================================
--- linux-2.6.orig/include/linux/sched.h
+++ linux-2.6/include/linux/sched.h
@@ -1056,6 +1056,7 @@ static inline void put_task_struct(struc
 #define PF_SPREAD_SLAB 0x02000000      /* Spread some slab caches over cpuset 
*/
 #define PF_MEMPOLICY   0x10000000      /* Non-default NUMA mempolicy */
 #define PF_MUTEX_TESTER        0x20000000      /* Thread belongs to the rt 
mutex tester */
+#define PF_MEM_NOWAIT  0x40000000      /* Make allocations fail instead of 
block */
 
 /*
  * Only the _current_ task can read/write to tsk->flags, but other
Index: linux-2.6/mm/page_alloc.c
===================================================================
--- linux-2.6.orig/mm/page_alloc.c
+++ linux-2.6/mm/page_alloc.c
@@ -912,11 +912,11 @@ struct page * fastcall
 __alloc_pages(gfp_t gfp_mask, unsigned int order,
                struct zonelist *zonelist)
 {
-       const gfp_t wait = gfp_mask & __GFP_WAIT;
+       struct task_struct *p = current;
+       const int wait = (gfp_mask & __GFP_WAIT) && !(p->flags & PF_MEM_NOWAIT);
        struct zone **z;
        struct page *page;
        struct reclaim_state reclaim_state;
-       struct task_struct *p = current;
        int do_retry;
        int alloc_flags;
        int did_some_progress;

--
-
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