linux_dsm_epyc7002/fs
Mike Galbraith 5091faa449 sched: Add 'autogroup' scheduling feature: automated per session task groups
A recurring complaint from CFS users is that parallel kbuild has
a negative impact on desktop interactivity.  This patch
implements an idea from Linus, to automatically create task
groups.  Currently, only per session autogroups are implemented,
but the patch leaves the way open for enhancement.

Implementation: each task's signal struct contains an inherited
pointer to a refcounted autogroup struct containing a task group
pointer, the default for all tasks pointing to the
init_task_group.  When a task calls setsid(), a new task group
is created, the process is moved into the new task group, and a
reference to the preveious task group is dropped.  Child
processes inherit this task group thereafter, and increase it's
refcount.  When the last thread of a process exits, the
process's reference is dropped, such that when the last process
referencing an autogroup exits, the autogroup is destroyed.

At runqueue selection time, IFF a task has no cgroup assignment,
its current autogroup is used.

Autogroup bandwidth is controllable via setting it's nice level
through the proc filesystem:

  cat /proc/<pid>/autogroup

Displays the task's group and the group's nice level.

  echo <nice level> > /proc/<pid>/autogroup

Sets the task group's shares to the weight of nice <level> task.
Setting nice level is rate limited for !admin users due to the
abuse risk of task group locking.

The feature is enabled from boot by default if
CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via
the boot option noautogroup, and can also be turned on/off on
the fly via:

  echo [01] > /proc/sys/kernel/sched_autogroup_enabled

... which will automatically move tasks to/from the root task group.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Paul Turner <pjt@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
[ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 16:03:35 +01:00
..
9p
adfs
affs
afs
autofs4
befs
bfs
btrfs
cachefiles
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2010-11-19 15:32:22 -08:00
cifs
coda
configfs
cramfs
debugfs
devpts
dlm
ecryptfs BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
efs
exofs
exportfs
ext2
ext3 BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
ext4 ext4: Add EXT4_IOC_TRIM ioctl to handle batched discard 2010-11-19 21:47:07 -05:00
fat
freevxfs
fscache
fuse
gfs2
hfs
hfsplus
hostfs
hpfs
hppfs
hugetlbfs
isofs
jbd
jbd2 jbd2: fix /proc/fs/jbd2/<dev> when using an external journal 2010-11-17 21:46:26 -05:00
jffs2
jfs
lockd BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
logfs
minix
ncpfs BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
nfs BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
nfs_common
nfsd BKL: remove references to lock_kernel from comments 2010-11-17 08:59:32 -08:00
nilfs2
nls
notify
ntfs
ocfs2 BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
omfs
openpromfs
partitions
proc sched: Add 'autogroup' scheduling feature: automated per session task groups 2010-11-30 16:03:35 +01:00
qnx4
quota
ramfs
reiserfs BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
romfs
squashfs
sysfs
sysv
ubifs
udf
ufs
xfs
aio.c
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio-integrity.c
bio.c
block_dev.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
buffer.c
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
compat.c
dcache.c
dcookies.c
direct-io.c
drop_caches.c
eventfd.c
eventpoll.c
exec.c
fcntl.c
fifo.c
file_table.c
file.c
filesystems.c
fs_struct.c
fs-writeback.c
generic_acl.c
inode.c
internal.h
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
Kconfig
Kconfig.binfmt
libfs.c
locks.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
Makefile
mbcache.c
mpage.c
namei.c
namespace.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
nfsctl.c
no-block.c
open.c
pipe.c
pnode.c
pnode.h
posix_acl.c
read_write.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
read_write.h
readdir.c
select.c
seq_file.c
signalfd.c
splice.c
stack.c
stat.c
statfs.c
super.c
sync.c
timerfd.c
utimes.c
xattr_acl.c
xattr.c