linux/ipc
Lee Schermerhorn 89e004ea55 SHM_LOCKED pages are unevictable
Shmem segments locked into memory via shmctl(SHM_LOCKED) should not be
kept on the normal LRU, since scanning them is a waste of time and might
throw off kswapd's balancing algorithms.  Place them on the unevictable
LRU list instead.

Use the AS_UNEVICTABLE flag to mark address_space of SHM_LOCKed shared
memory regions as unevictable.  Then these pages will be culled off the
normal LRU lists during vmscan.

Add new wrapper function to clear the mapping's unevictable state when/if
shared memory segment is munlocked.

Add 'scan_mapping_unevictable_page()' to mm/vmscan.c to scan all pages in
the shmem segment's mapping [struct address_space] for evictability now
that they're no longer locked.  If so, move them to the appropriate zone
lru list.

Changes depend on [CONFIG_]UNEVICTABLE_LRU.

[kosaki.motohiro@jp.fujitsu.com: revert shm change]
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Kosaki Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:50:26 -07:00
..
Makefile ipc: recompute msgmni on ipc namespace creation/removal 2008-04-29 08:06:12 -07:00
compat.c fix logic error in ipc compat semctl() 2007-07-06 10:23:43 -07:00
compat_mq.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ipc_sysctl.c sysctl: simplify ->strategy 2008-10-16 11:21:47 -07:00
ipcns_notifier.c ipc: do not use a negative value to re-enable msgmni automatic recomputing 2008-07-25 10:53:42 -07:00
mqueue.c [PATCH] kill nameidata passing to permission(), rename to inode_permission() 2008-07-26 20:53:31 -04:00
msg.c ipc: only output msgmni value at boot time 2008-06-06 11:29:12 -07:00
msgutil.c [PATCH] getting rid of all casts of k[cmz]alloc() calls 2006-12-13 09:05:58 -08:00
namespace.c ipc: recompute msgmni on ipc namespace creation/removal 2008-04-29 08:06:12 -07:00
sem.c ipc/sem.c: make free_un() static 2008-10-16 11:21:51 -07:00
shm.c SHM_LOCKED pages are unevictable 2008-10-20 08:50:26 -07:00
util.c ipc: get rid of ipc_lock_down() 2008-07-25 10:53:42 -07:00
util.h ipc: get rid of ipc_lock_down() 2008-07-25 10:53:42 -07:00