linux.git/mm/oom_kill.c, branch v2.6.19

[PATCH] OOM killer meets userspace headers

2006-10-20T17:26:38+00:00

Despite mm.h is not being exported header, it does contain one thing
which is part of userspace ABI -- value disabling OOM killer for given
process. So,
a) create and export include/linux/oom.h
b) move OOM_DISABLE define there.
c) turn bounding values of /proc/$PID/oom_adj into defines and export
   them too.

Note: mass __KERNEL__ removal will be done later.

Signed-off-by: Alexey Dobriyan 
Cc: Nick Piggin 
Cc: David Woodhouse 
Cc: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] oom: don't kill current when another OOM in progress

2006-09-29T16:18:21+00:00

A previous patch to allow an exiting task to OOM kill itself (and thereby
avoid a little deadlock) introduced a problem.  We don't want the
PF_EXITING task, even if it is 'current', to access mem reserves if there
is already a TIF_MEMDIE process in the system sucking up reserves.

Also make the commenting a little bit clearer, and note that our current
scheme of effectively single threading the OOM killer is not itself
perfect.

Signed-off-by: Nick Piggin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] oom_kill_task(): cleanup ->mm checks

2006-09-29T16:18:21+00:00

- It is not possible to have task->mm == &init_mm.

- task_lock() buys nothing for 'if (!p->mm)' check.

Signed-off-by: Oleg Nesterov 
Cc: Nick Piggin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] select_bad_process(): cleanup 'releasing' check

2006-09-29T16:18:21+00:00

No logic changes, but imho easier to read.

Signed-off-by: Oleg Nesterov 
Acked-by: Nick Piggin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] select_bad_process(): kill a bogus PF_DEAD/TASK_DEAD check

2006-09-29T16:18:21+00:00

The only one usage of TASK_DEAD outside of last schedule path,

select_bad_process:

	for_each_task(p) {

		if (!p->mm)
			continue;
		...
			if (p->state == TASK_DEAD)
				continue;
		...

TASK_DEAD state is set at the end of do_exit(), this means that p->mm
was already set == NULL by exit_mm(), so this task was already rejected
by 'if (!p->mm)' above.

Note also that the caller holds tasklist_lock, this means that p can't
pass exit_notify() and then set TASK_DEAD when p->mm != NULL.

Also, remove open-coded is_init().

Signed-off-by: Oleg Nesterov 
Cc: Ingo Molnar 
Cc: Nick Piggin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] introduce TASK_DEAD state

2006-09-29T16:18:21+00:00

I am not sure about this patch, I am asking Ingo to take a decision.

task_struct->state == EXIT_DEAD is a very special case, to avoid a confusion
it makes sense to introduce a new state, TASK_DEAD, while EXIT_DEAD should
live only in ->exit_state as documented in sched.h.

Note that this state is not visible to user-space, get_task_state() masks off
unsuitable states.

Signed-off-by: Oleg Nesterov 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] kill PF_DEAD flag

2006-09-29T16:18:20+00:00

After the previous change (->flags & PF_DEAD) <=> (->state == EXIT_DEAD), we
don't need PF_DEAD any longer.

Signed-off-by: Oleg Nesterov 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] pidspace: is_init()

2006-09-29T16:18:12+00:00

This is an updated version of Eric Biederman's is_init() patch.
(http://lkml.org/lkml/2006/2/6/280).  It applies cleanly to 2.6.18-rc3 and
replaces a few more instances of ->pid == 1 with is_init().

Further, is_init() checks pid and thus removes dependency on Eric's other
patches for now.

Eric's original description:

	There are a lot of places in the kernel where we test for init
	because we give it special properties.  Most  significantly init
	must not die.  This results in code all over the kernel test
	->pid == 1.

	Introduce is_init to capture this case.

	With multiple pid spaces for all of the cases affected we are
	looking for only the first process on the system, not some other
	process that has pid == 1.

Signed-off-by: Eric W. Biederman 
Signed-off-by: Sukadev Bhattiprolu 
Cc: Dave Hansen 
Cc: Serge Hallyn 
Cc: Cedric Le Goater 
Cc: 
Acked-by: Paul Mackerras 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] NUMA: Add zone_to_nid function

2006-09-26T15:48:52+00:00

There are many places where we need to determine the node of a zone.
Currently we use a difficult to read sequence of pointer dereferencing.
Put that into an inline function and use throughout VM.  Maybe we can find
a way to optimize the lookup in the future.

Signed-off-by: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] oom-kill: update comments to reflect current code

2006-09-26T15:48:52+00:00

Update the comments for __oom_kill_task() to reflect the code changes.

Signed-off-by: Ram Gupta 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds