Commit b1f099b1 authored by Yury Norov's avatar Yury Norov Committed by Ingo Molnar
Browse files

numa: Generalize numa_map_to_online_node() 



The function in fact searches the nearest node for a given one,
based on a N_ONLINE state. This is a common pattern to search
for a nearest node.

This patch converts numa_map_to_online_node() to numa_nearest_node()
so that others won't need to opencode the logic.

Signed-off-by: default avatarYury Norov <yury.norov@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Link: https://lore.kernel.org/r/20230819141239.287290-2-yury.norov@gmail.com
parent 4de7b17f

include/linux/numa.h

+5 −2
Original line number Diff line number Diff line
@@ -25,7 +25,7 @@ 
#include <asm/sparsemem.h>



/* Generic implementation available */

int numa_map_to_online_node(int node);

int numa_nearest_node(int node, unsigned int state);



#ifndef memory_add_physaddr_to_nid

static inline int memory_add_physaddr_to_nid(u64 start)
@@ -44,10 +44,11 @@ static inline int phys_to_target_node(u64 start) 
}

#endif

#else /* !CONFIG_NUMA */

static inline int numa_map_to_online_node(int node)

static inline int numa_nearest_node(int node, unsigned int state)

{

	return NUMA_NO_NODE;

}



static inline int memory_add_physaddr_to_nid(u64 start)

{

	return 0;
@@ -58,6 +59,8 @@ static inline int phys_to_target_node(u64 start) 
}

#endif



#define numa_map_to_online_node(node) numa_nearest_node(node, N_ONLINE)



#ifdef CONFIG_HAVE_ARCH_NODE_DEV_GROUP

extern const struct attribute_group arch_node_dev_group;

#endif

mm/mempolicy.c

+11 −7
Original line number Diff line number Diff line
@@ -131,22 +131,26 @@ static struct mempolicy default_policy = { 
static struct mempolicy preferred_node_policy[MAX_NUMNODES];



/**

 * numa_map_to_online_node - Find closest online node

 * numa_nearest_node - Find nearest node by state

 * @node: Node id to start the search

 * @state: State to filter the search

 *

 * Lookup the next closest node by distance if @nid is not online.

 * Lookup the closest node by distance if @nid is not in state.

 *

 * Return: this @node if it is online, otherwise the closest node by distance

 * Return: this @node if it is in state, otherwise the closest node by distance

 */

int numa_map_to_online_node(int node)

int numa_nearest_node(int node, unsigned int state)

{

	int min_dist = INT_MAX, dist, n, min_node;



	if (node == NUMA_NO_NODE || node_online(node))

	if (state >= NR_NODE_STATES)

		return -EINVAL;



	if (node == NUMA_NO_NODE || node_state(node, state))

		return node;



	min_node = node;

	for_each_online_node(n) {

	for_each_node_state(n, state) {

		dist = node_distance(node, n);

		if (dist < min_dist) {

			min_dist = dist;
@@ -156,7 +160,7 @@ int numa_map_to_online_node(int node) 


	return min_node;

}

EXPORT_SYMBOL_GPL(numa_map_to_online_node);

EXPORT_SYMBOL_GPL(numa_nearest_node);



struct mempolicy *get_task_policy(struct task_struct *p)

{