Commit 8d060bf4 authored by David Rientjes's avatar David Rientjes Committed by Linus Torvalds
Browse files

mm, oom: ensure memoryless node zonelist always includes zones 



With memoryless node support being worked on, it's possible that for
optimizations that a node may not have a non-NULL zonelist.  When
CONFIG_NUMA is enabled and node 0 is memoryless, this means the zonelist
for first_online_node may become NULL.

The oom killer requires a zonelist that includes all memory zones for
the sysrq trigger and pagefault out of memory handler.

Ensure that a non-NULL zonelist is always passed to the oom killer.

[akpm@linux-foundation.org: fix non-numa build]
Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6e90b58b

drivers/tty/sysrq.c

+1 −1
Original line number Diff line number Diff line
@@ -355,7 +355,7 @@ static struct sysrq_key_op sysrq_term_op = { 


static void moom_callback(struct work_struct *ignored)

{

	out_of_memory(node_zonelist(first_online_node, GFP_KERNEL), GFP_KERNEL,

	out_of_memory(node_zonelist(first_memory_node, GFP_KERNEL), GFP_KERNEL,

		      0, NULL, true);

}

include/linux/nodemask.h

+10 −1
Original line number Diff line number Diff line
@@ -430,7 +430,15 @@ static inline int num_node_state(enum node_states state) 
	for_each_node_mask((__node), node_states[__state])



#define first_online_node	first_node(node_states[N_ONLINE])

#define next_online_node(nid)	next_node((nid), node_states[N_ONLINE])

#define first_memory_node	first_node(node_states[N_MEMORY])

static inline int next_online_node(int nid)

{

	return next_node(nid, node_states[N_ONLINE]);

}

static inline int next_memory_node(int nid)

{

	return next_node(nid, node_states[N_MEMORY]);

}



extern int nr_node_ids;

extern int nr_online_nodes;
@@ -471,6 +479,7 @@ static inline int num_node_state(enum node_states state) 
	for ( (node) = 0; (node) == 0; (node) = 1)



#define first_online_node	0

#define first_memory_node	0

#define next_online_node(nid)	(MAX_NUMNODES)

#define nr_node_ids		1

#define nr_online_nodes		1

mm/oom_kill.c

+1 −1
Original line number Diff line number Diff line
@@ -694,7 +694,7 @@ void pagefault_out_of_memory(void) 
	if (mem_cgroup_oom_synchronize(true))

		return;



	zonelist = node_zonelist(first_online_node, GFP_KERNEL);

	zonelist = node_zonelist(first_memory_node, GFP_KERNEL);

	if (try_set_zonelist_oom(zonelist, GFP_KERNEL)) {

		out_of_memory(NULL, 0, 0, NULL, false);

		clear_zonelist_oom(zonelist, GFP_KERNEL);

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