Commit c00eb15a authored by Yaowei Bai's avatar Yaowei Bai Committed by Linus Torvalds
Browse files

mm/zonelist: enumerate zonelists array index 



Hardcoding index to zonelists array in gfp_zonelist() is not a good
idea, let's enumerate it to improve readability.

No functional change.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix CONFIG_NUMA=n build]
[n-horiguchi@ah.jp.nec.com: fix warning in comparing enumerator]
Signed-off-by: default avatarYaowei Bai <baiyaowei@cmss.chinamobile.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 06640290

include/linux/gfp.h

+5 −4
Original line number Diff line number Diff line
@@ -384,10 +384,11 @@ static inline enum zone_type gfp_zone(gfp_t flags) 


static inline int gfp_zonelist(gfp_t flags)

{

	if (IS_ENABLED(CONFIG_NUMA) && unlikely(flags & __GFP_THISNODE))

		return 1;



	return 0;

#ifdef CONFIG_NUMA

	if (unlikely(flags & __GFP_THISNODE))

		return ZONELIST_NOFALLBACK;

#endif

	return ZONELIST_FALLBACK;

}



/*

include/linux/mmzone.h

+9 −11
Original line number Diff line number Diff line
@@ -571,19 +571,17 @@ static inline bool zone_is_empty(struct zone *zone) 
/* Maximum number of zones on a zonelist */

#define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)



enum {

	ZONELIST_FALLBACK,	/* zonelist with fallback */

#ifdef CONFIG_NUMA



	/*

 * The NUMA zonelists are doubled because we need zonelists that restrict the

 * allocations to a single node for __GFP_THISNODE.

 *

 * [0]	: Zonelist with fallback

 * [1]	: No fallback (__GFP_THISNODE)

	 * The NUMA zonelists are doubled because we need zonelists that

	 * restrict the allocations to a single node for __GFP_THISNODE.

	 */

#define MAX_ZONELISTS 2

#else

#define MAX_ZONELISTS 1

	ZONELIST_NOFALLBACK,	/* zonelist without fallback (__GFP_THISNODE) */

#endif

	MAX_ZONELISTS

};



/*

 * This struct contains information about a zone in a zonelist. It is stored

mm/page_alloc.c

+4 −5
Original line number Diff line number Diff line
@@ -4148,8 +4148,7 @@ static void set_zonelist_order(void) 


static void build_zonelists(pg_data_t *pgdat)

{

	int j, node, load;

	enum zone_type i;

	int i, node, load;

	nodemask_t used_mask;

	int local_node, prev_node;

	struct zonelist *zonelist;
@@ -4169,7 +4168,7 @@ static void build_zonelists(pg_data_t *pgdat) 
	nodes_clear(used_mask);



	memset(node_order, 0, sizeof(node_order));

	j = 0;

	i = 0;



	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {

		/*
@@ -4186,12 +4185,12 @@ static void build_zonelists(pg_data_t *pgdat) 
		if (order == ZONELIST_ORDER_NODE)

			build_zonelists_in_node_order(pgdat, node);

		else

			node_order[j++] = node;	/* remember order */

			node_order[i++] = node;	/* remember order */

	}



	if (order == ZONELIST_ORDER_ZONE) {

		/* calculate node order -- i.e., DMA last! */

		build_zonelists_in_zone_order(pgdat, j);

		build_zonelists_in_zone_order(pgdat, i);

	}



	build_thisnode_zonelists(pgdat);

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