Commit 4365a567 authored by KAMEZAWA Hiroyuki's avatar KAMEZAWA Hiroyuki Committed by Linus Torvalds
Browse files

oom-kill: fix NUMA constraint check with nodemask 



Fix node-oriented allocation handling in oom-kill.c I myself think of this
as a bugfix not as an ehnancement.

In these days, things are changed as
  - alloc_pages() eats nodemask as its arguments, __alloc_pages_nodemask().
  - mempolicy don't maintain its own private zonelists.
  (And cpuset doesn't use nodemask for __alloc_pages_nodemask())

So, current oom-killer's check function is wrong.

This patch does
  - check nodemask, if nodemask && nodemask doesn't cover all
    node_states[N_HIGH_MEMORY], this is CONSTRAINT_MEMORY_POLICY.
  - Scan all zonelist under nodemask, if it hits cpuset's wall
    this faiulre is from cpuset.
And
  - modifies the caller of out_of_memory not to call oom if __GFP_THISNODE.
    This doesn't change "current" behavior. If callers use __GFP_THISNODE
    it should handle "page allocation failure" by itself.

  - handle __GFP_NOFAIL+__GFP_THISNODE path.
    This is something like a FIXME but this gfpmask is not used now.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hioryu@jp.fujitsu.com>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3b4798cb

drivers/char/sysrq.c

+1 −1
Original line number Diff line number Diff line
@@ -339,7 +339,7 @@ static struct sysrq_key_op sysrq_term_op = { 


static void moom_callback(struct work_struct *ignored)

{

	out_of_memory(node_zonelist(0, GFP_KERNEL), GFP_KERNEL, 0);

	out_of_memory(node_zonelist(0, GFP_KERNEL), GFP_KERNEL, 0, NULL);

}



static DECLARE_WORK(moom_work, moom_callback);

include/linux/oom.h

+3 −1
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#ifdef __KERNEL__



#include <linux/types.h>

#include <linux/nodemask.h>



struct zonelist;

struct notifier_block;
@@ -26,7 +27,8 @@ enum oom_constraint { 
extern int try_set_zone_oom(struct zonelist *zonelist, gfp_t gfp_flags);

extern void clear_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_flags);



extern void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order);

extern void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,

		int order, nodemask_t *mask);

extern int register_oom_notifier(struct notifier_block *nb);

extern int unregister_oom_notifier(struct notifier_block *nb);

mm/oom_kill.c

+33 −13
Original line number Diff line number Diff line
@@ -196,27 +196,46 @@ unsigned long badness(struct task_struct *p, unsigned long uptime) 
/*

 * Determine the type of allocation constraint.

 */

static inline enum oom_constraint constrained_alloc(struct zonelist *zonelist,

						    gfp_t gfp_mask)

{

#ifdef CONFIG_NUMA

static enum oom_constraint constrained_alloc(struct zonelist *zonelist,

				    gfp_t gfp_mask, nodemask_t *nodemask)

{

	struct zone *zone;

	struct zoneref *z;

	enum zone_type high_zoneidx = gfp_zone(gfp_mask);

	nodemask_t nodes = node_states[N_HIGH_MEMORY];



	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)

		if (cpuset_zone_allowed_softwall(zone, gfp_mask))

			node_clear(zone_to_nid(zone), nodes);

		else

			return CONSTRAINT_CPUSET;

	/*

	 * Reach here only when __GFP_NOFAIL is used. So, we should avoid

	 * to kill current.We have to random task kill in this case.

	 * Hopefully, CONSTRAINT_THISNODE...but no way to handle it, now.

	 */

	if (gfp_mask & __GFP_THISNODE)

		return CONSTRAINT_NONE;



	if (!nodes_empty(nodes))

	/*

	 * The nodemask here is a nodemask passed to alloc_pages(). Now,

	 * cpuset doesn't use this nodemask for its hardwall/softwall/hierarchy

	 * feature. mempolicy is an only user of nodemask here.

	 * check mempolicy's nodemask contains all N_HIGH_MEMORY

	 */

	if (nodemask && !nodes_subset(node_states[N_HIGH_MEMORY], *nodemask))

		return CONSTRAINT_MEMORY_POLICY;

#endif



	/* Check this allocation failure is caused by cpuset's wall function */

	for_each_zone_zonelist_nodemask(zone, z, zonelist,

			high_zoneidx, nodemask)

		if (!cpuset_zone_allowed_softwall(zone, gfp_mask))

			return CONSTRAINT_CPUSET;



	return CONSTRAINT_NONE;

}

#else

static enum oom_constraint constrained_alloc(struct zonelist *zonelist,

				gfp_t gfp_mask, nodemask_t *nodemask)

{

	return CONSTRAINT_NONE;

}

#endif



/*

 * Simple selection loop. We chose the process with the highest
@@ -613,7 +632,8 @@ rest_and_return: 
 * OR try to be smart about which process to kill. Note that we

 * don't have to be perfect here, we just have to be good.

 */

void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)

void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,

		int order, nodemask_t *nodemask)

{

	unsigned long freed = 0;

	enum oom_constraint constraint;
@@ -632,7 +652,7 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order) 
	 * Check if there were limitations on the allocation (only relevant for

	 * NUMA) that may require different handling.

	 */

	constraint = constrained_alloc(zonelist, gfp_mask);

	constraint = constrained_alloc(zonelist, gfp_mask, nodemask);

	read_lock(&tasklist_lock);



	switch (constraint) {

mm/page_alloc.c

+16 −6
Original line number Diff line number Diff line
@@ -1654,12 +1654,22 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, 
	if (page)

		goto out;



	if (!(gfp_mask & __GFP_NOFAIL)) {

		/* The OOM killer will not help higher order allocs */

	if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_NOFAIL))

		if (order > PAGE_ALLOC_COSTLY_ORDER)

			goto out;



		/*

		 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.

		 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.

		 * The caller should handle page allocation failure by itself if

		 * it specifies __GFP_THISNODE.

		 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.

		 */

		if (gfp_mask & __GFP_THISNODE)

			goto out;

	}

	/* Exhausted what can be done so it's blamo time */

	out_of_memory(zonelist, gfp_mask, order);

	out_of_memory(zonelist, gfp_mask, order, nodemask);



out:

	clear_zonelist_oom(zonelist, gfp_mask);

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