[PATCH] SHM_NORESERVE flags for shmget()

Add SHM_NORESERVE functionality similar to MAP_NORESERVE for shared memory
segments.

This is mainly to avoid abuse of OVERCOMMIT_ALWAYS and this flag is ignored
for OVERCOMMIT_NEVER.

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/shm.h b/include/linux/shm.h
index 80113a1f60bc..a2c896ad0bef 100644
--- a/include/linux/shm.h
+++ b/include/linux/shm.h
@@ -92,6 +92,7 @@ struct shmid_kernel /* private to the kernel */
 #define SHM_DEST        01000   /* segment will be destroyed on last detach */
 #define SHM_LOCKED      02000   /* segment will not be swapped */
 #define SHM_HUGETLB     04000   /* segment will use huge TLB pages */
+#define SHM_NORESERVE   010000  /* don't check for reservations */
 
 #ifdef CONFIG_SYSVIPC
 long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr);