linux-toradex.git/kernel/cgroup.c, branch v2.6.26-rc3

mm: bdi: add separate writeback accounting capability

2008-04-30T15:29:50+00:00

Add a new BDI capability flag: BDI_CAP_NO_ACCT_WB.  If this flag is
set, then don't update the per-bdi writeback stats from
test_set_page_writeback() and test_clear_page_writeback().

Misc cleanups:

 - convert bdi_cap_writeback_dirty() and friends to static inline functions
 - create a flag that includes all three dirty/writeback related flags,
   since almst all users will want to have them toghether

Signed-off-by: Miklos Szeredi 
Cc: Peter Zijlstra 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cgroups: add an owner to the mm_struct

2008-04-29T15:06:10+00:00

Remove the mem_cgroup member from mm_struct and instead adds an owner.

This approach was suggested by Paul Menage.  The advantage of this approach
is that, once the mm->owner is known, using the subsystem id, the cgroup
can be determined.  It also allows several control groups that are
virtually grouped by mm_struct, to exist independent of the memory
controller i.e., without adding mem_cgroup's for each controller, to
mm_struct.

A new config option CONFIG_MM_OWNER is added and the memory resource
controller selects this config option.

This patch also adds cgroup callbacks to notify subsystems when mm->owner
changes.  The mm_cgroup_changed callback is called with the task_lock() of
the new task held and is called just prior to changing the mm->owner.

I am indebted to Paul Menage for the several reviews of this patchset and
helping me make it lighter and simpler.

This patch was tested on a powerpc box, it was compiled with both the
MM_OWNER config turned on and off.

After the thread group leader exits, it's moved to init_css_state by
cgroup_exit(), thus all future charges from runnings threads would be
redirected to the init_css_set's subsystem.

Signed-off-by: Balbir Singh 
Cc: Pavel Emelianov 
Cc: Hugh Dickins 
Cc: Sudhir Kumar 
Cc: YAMAMOTO Takashi 
Cc: Hirokazu Takahashi 
Cc: David Rientjes ,
Cc: Balbir Singh 
Acked-by: KAMEZAWA Hiroyuki 
Acked-by: Pekka Enberg 
Reviewed-by: Paul Menage 
Cc: Oleg Nesterov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cgroups: introduce cft->read_seq()

2008-04-29T15:06:10+00:00

Introduce a read_seq() helper in cftype, which uses seq_file to print out
lists.  Use it in the devices cgroup.  Also split devices.allow into two
files, so now devices.deny and devices.allow are the ones to use to manipulate
the whitelist, while devices.list outputs the cgroup's current whitelist.

Signed-off-by: Serge E. Hallyn 
Acked-by: Paul Menage 
Cc: Balbir Singh 
Cc: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cgroups: remove the css_set linked-list

2008-04-29T15:06:10+00:00

Now we can run through the hash table instead of running through the
linked-list.

Signed-off-by: Li Zefan 
Reviewed-by: Paul Menage 
Cc: Balbir Singh 
Cc: Pavel Emelyanov 
Cc: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cgroups: simplify init_subsys()

2008-04-29T15:06:10+00:00

We are at system boot and there is only 1 cgroup group (i,e, init_css_set), so
we don't need to run through the css_set linked list.  Neither do we need to
run through the task list, since no processes have been created yet.

Also referring to a comment in cgroup.h:

struct css_set
{
	...
	/*
	 * Set of subsystem states, one for each subsystem. This array
	 * is immutable after creation apart from the init_css_set
	 * during subsystem registration (at boot time).
	 */
	struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];
}

Signed-off-by: Li Zefan 
Reviewed-by: Paul Menage 
Cc: Balbir Singh 
Cc: Pavel Emelyanov 
Cc: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cgroups: use a hash table for css_set finding

2008-04-29T15:06:09+00:00

When we attach a process to a different cgroup, the css_set linked-list will
be run through to find a suitable existing css_set to use.  This patch
implements a hash table for better performance.

The following benchmarks have been tested:

For N in 1, 5, 10, 50, 100, 500, 1000, create N cgroups with one sleeping
task in each, and then move an additional task through each cgroup in
turn.

Here is a test result:

N	Loop	orig - Time(s)	hash - Time(s)
----------------------------------------------
1	10000	1.201231728	1.196311177
5	2000	1.065743872	1.040566424
10	1000	0.991054735	0.986876440
50	200	0.976554203	0.969608733
100	100	0.998504680	0.969218270
500	20	1.157347764	0.962602963
1000	10	1.619521852	1.085140172

Signed-off-by: Li Zefan 
Reviewed-by: Paul Menage 
Cc: Balbir Singh 
Cc: Pavel Emelyanov 
Cc: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cgroups: add the trigger callback to struct cftype

2008-04-29T15:06:09+00:00

Trigger callback can be used to receive a kick-up from the user space.  The
string written is ignored.

The cftype->private is used for multiplexing events.

Signed-off-by: Pavel Emelyanov 
Acked-by: Paul Menage 
Acked-by: KAMEZAWA Hiroyuki 
Cc: Balbir Singh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cgroup: switch to proc_create()

2008-04-29T15:06:09+00:00

There is a race between create_proc_entry() and the assignment of file ops.
proc_create() is invented to fix it.

Signed-off-by: Li Zefan 
Acked-by: Paul Menage 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cgroup: annotate cgroup_init_subsys with __init

2008-04-29T15:06:09+00:00

It is called by cgroup_init() and cgroup_init_early() only, which are
annotated with __init.

Signed-off-by: Li Zefan 
Cc: Paul Menage 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

CGroups _s64 files: add cgroups read_s64/write_s64 file methods

2008-04-29T15:06:09+00:00

These patches add cgroups read_s64 and write_s64 control file methods (the
signed equivalent of read_u64/write_u64) and use them to implement the
cpu.rt_runtime_us control file in the CFS cgroup subsystem.

This patch:

These are the signed equivalents of the read_u64/write_u64 methods

Signed-off-by: Paul Menage 
Acked-by: Peter Zijlstra 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds