linux/fs
Mandeep Singh Baines dabb16f639 oom: allow a non-CAP_SYS_RESOURCE proces to oom_score_adj down
We'd like to be able to oom_score_adj a process up/down as it
enters/leaves the foreground.  Currently, it is not possible to oom_adj
down without CAP_SYS_RESOURCE.  This patch allows a task to decrease its
oom_score_adj back to the value that a CAP_SYS_RESOURCE thread set it to
or its inherited value at fork.  Assuming the thread that has forked it
has oom_score_adj of 0, each process could decrease it back from 0 upon
activation unless a CAP_SYS_RESOURCE thread elevated it to something
higher.

Alternative considered:

* a setuid binary
* a daemon with CAP_SYS_RESOURCE

Since you don't wan't all processes to be able to reduce their oom_adj, a
setuid or daemon implementation would be complex.  The alternatives also
have much higher overhead.

This patch updated from original patch based on feedback from David
Rientjes.

Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:35 -08:00
..
9p switch 9p 2011-01-12 20:03:43 -05:00
adfs switch adfs 2011-01-12 20:02:45 -05:00
affs switch affs 2011-01-12 20:03:42 -05:00
afs switch afs 2011-01-12 20:04:20 -05:00
autofs4 fs: rcu-walk aware d_revalidate method 2011-01-07 17:50:29 +11:00
befs befs: don't pass huge structs by value 2011-01-13 08:03:15 -08:00
bfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
btrfs Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
cachefiles llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2011-01-13 10:25:24 -08:00
cifs switch cifs 2011-01-12 20:02:46 -05:00
coda Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-01-13 10:27:28 -08:00
configfs switch configfs 2011-01-12 20:03:12 -05:00
cramfs cramfs: generate unique inode number for better inode cache usage 2011-01-13 08:03:23 -08:00
debugfs convert get_sb_single() users 2010-10-29 04:16:28 -04:00
devpts convert get_sb_single() users 2010-10-29 04:16:28 -04:00
dlm dlm: sanitize work_start() in lowcomms.c 2010-12-13 13:42:24 -06:00
ecryptfs ecryptfs: fix broken build 2011-01-13 17:19:38 -08:00
efs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
exofs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
exportfs fs: dcache per-inode inode alias locking 2011-01-07 17:50:31 +11:00
ext2 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 2011-01-11 14:37:31 -08:00
ext3 Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
ext4 Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
fat switch fat to ->s_d_op, close exportfs races there 2011-01-12 20:02:43 -05:00
freevxfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
fscache Add a dummy printk function for the maintenance of unused printks 2010-08-12 09:51:35 -07:00
fuse switch fuse 2011-01-12 20:02:44 -05:00
gfs2 Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
hfs switch hfs 2011-01-12 20:02:45 -05:00
hfsplus switch hfsplus 2011-01-12 20:02:45 -05:00
hostfs switch hostfs 2011-01-12 20:03:42 -05:00
hpfs switch hpfs 2011-01-12 20:02:47 -05:00
hppfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
hugetlbfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
isofs fix isofs d_op handling 2011-01-12 20:02:43 -05:00
jbd fix comment typos concerning "consistent" 2010-12-10 16:04:28 +01:00
jbd2 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2011-01-13 10:05:56 -08:00
jffs2 fs: provide rcu-walk aware permission i_ops 2011-01-07 17:50:29 +11:00
jfs Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
lockd lockd: double unlock in next_host_state() 2011-01-04 13:10:37 -05:00
logfs Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
minix minixfs: kill dead code 2011-01-12 20:02:44 -05:00
ncpfs move internal-only parts of ncpfs headers to fs/ncpfs 2011-01-12 20:03:43 -05:00
nfs NFS: Fix NFSv3 exclusive open semantics 2011-01-13 12:06:29 -08:00
nfs_common
nfsd Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
nilfs2 Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
nls
notify Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2011-01-13 10:05:56 -08:00
ntfs NTFS: writev() fix and maintenance/contact details update 2011-01-12 08:35:53 -08:00
ocfs2 Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
omfs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
openpromfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
partitions Merge branch 'for-2.6.38/event-handling' into for-2.6.38/core 2011-01-13 14:47:54 +01:00
proc oom: allow a non-CAP_SYS_RESOURCE proces to oom_score_adj down 2011-01-13 17:32:35 -08:00
qnx4 fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
quota quota: Use %pV and __attribute__((format (printf in __quota_error and fix fallout 2011-01-10 19:04:05 +01:00
ramfs convert get_sb_nodev() users 2010-10-29 04:16:31 -04:00
reiserfs Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
romfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
squashfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
sysfs Merge branch 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6 2011-01-10 16:10:33 -08:00
sysv switch sysv 2011-01-12 20:02:44 -05:00
ubifs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
udf Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-udf-2.6 2011-01-11 14:45:52 -08:00
ufs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
xfs Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
aio.c aio: remove unused aio_run_iocbs() 2011-01-13 08:03:22 -08:00
anon_inodes.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-01-13 10:27:28 -08:00
attr.c
bad_inode.c fs: provide rcu-walk aware permission i_ops 2011-01-07 17:50:29 +11:00
binfmt_aout.c Don't dump task struct in a.out core-dumps 2010-10-14 10:57:40 -07:00
binfmt_elf_fdpic.c
binfmt_elf.c binfmt_elf: cleanups 2011-01-13 08:03:12 -08:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c convert get_sb_single() users 2010-10-29 04:16:28 -04:00
binfmt_script.c Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
binfmt_som.c
bio-integrity.c bio-integrity: mark kintegrityd_wq highpri and CPU intensive 2011-01-03 15:01:48 +01:00
bio.c bio: take care not overflow page count when mapping/copying user data 2010-11-10 14:40:43 +01:00
block_dev.c Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
buffer.c fs: Use this_cpu_inc_return in buffer.c 2010-12-17 15:18:05 +01:00
char_dev.c Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
compat_binfmt_elf.c
compat_ioctl.c Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6 2011-01-07 14:39:20 -08:00
compat.c exec: copy-and-paste the fixes into compat_do_execve() paths 2010-11-30 17:56:38 -08:00
dcache.c fs: fix kernel-doc for dcache::prepend_path 2011-01-12 20:06:57 -05:00
dcookies.c
direct-io.c fs/direct-io.c: fix truncation error in dio_complete() return 2010-10-26 16:52:13 -07:00
drop_caches.c
eventfd.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
eventpoll.c epoll: convert max_user_watches to long 2011-01-13 08:03:12 -08:00
exec.c install_special_mapping skips security_file_mmap check. 2010-12-15 12:30:36 -08:00
fcntl.c fasync: Fix placement of FASYNC flag comment 2010-10-27 18:17:02 -07:00
fifo.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
file_table.c fs: allow for more than 2^31 files 2010-10-26 16:52:15 -07:00
file.c vfs: use kmalloc() to allocate fdmem if possible 2010-08-11 08:59:02 -07:00
filesystems.c fs: rcu-walk for path lookup 2011-01-07 17:50:27 +11:00
fs_struct.c fs: scale mntget/mntput 2011-01-07 17:50:33 +11:00
fs-writeback.c sync_inode_metadata: fix comment 2011-01-13 17:32:32 -08:00
generic_acl.c fs: provide simple rcu-walk generic_check_acl implementation 2011-01-07 17:50:29 +11:00
inode.c fs: avoid inode RCU freeing for pseudo fs 2011-01-07 17:50:26 +11:00
internal.h fs: scale mntget/mntput 2011-01-07 17:50:33 +11:00
ioctl.c Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 2010-11-19 19:46:45 -08:00
ioprio.c ioprio: grab rcu_read_lock in sys_ioprio_{set,get}() 2010-11-15 10:23:31 +01:00
Kconfig Merge 'staging-next' to Linus's tree 2010-10-28 09:44:56 -07:00
Kconfig.binfmt coredump: default CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS=y 2010-10-27 18:03:12 -07:00
libfs.c pass default dentry_operations to mount_pseudo() 2011-01-12 20:03:43 -05:00
locks.c fs: dcache scale dentry refcount 2011-01-07 17:50:21 +11:00
Makefile Merge 'staging-next' to Linus's tree 2010-10-28 09:44:56 -07:00
mbcache.c ext2: Resolve 'dereferencing pointer to incomplete type' when enabling EXT2_XATTR_DEBUG 2011-01-10 19:04:08 +01:00
mpage.c fs/mpage.c: consolidate code 2011-01-13 17:32:32 -08:00
namei.c vfs: pass struct file to do_truncate on O_TRUNC opens (try #2) 2011-01-12 20:06:59 -05:00
namespace.c fs: scale mntget/mntput 2011-01-07 17:50:33 +11:00
nfsctl.c
no-block.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
open.c fs: add hole punching to fallocate 2011-01-12 20:16:43 -05:00
pipe.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-01-13 10:27:28 -08:00
pnode.c fs: scale mntget/mntput 2011-01-07 17:50:33 +11:00
pnode.h
posix_acl.c
read_write.c fix signedness mess in rw_verify_area() on 64bit architectures 2011-01-12 20:06:58 -05:00
read_write.h
readdir.c
select.c fs/select.c: fix information leak to userspace 2011-01-13 08:03:12 -08:00
seq_file.c fs: take dcache_lock inside __d_path 2010-10-25 21:26:12 -04:00
signalfd.c Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 2010-10-26 10:13:10 -07:00
splice.c Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
stack.c
stat.c Mark arguments to certain syscalls as being const 2010-08-13 16:53:13 -07:00
statfs.c
super.c Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
sync.c
timerfd.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
utimes.c Mark arguments to certain syscalls as being const 2010-08-13 16:53:13 -07:00
xattr_acl.c
xattr.c