From c00eb15a8914b8ba84032a36044a5aaf7f71709d Mon Sep 17 00:00:00 2001 From: Yaowei Bai Date: Thu, 14 Jan 2016 15:19:00 -0800 Subject: [PATCH] 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: Yaowei Bai Cc: Michal Hocko Cc: David Rientjes Signed-off-by: Naoya Horiguchi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/gfp.h | 9 +++++---- include/linux/mmzone.h | 20 +++++++++----------- mm/page_alloc.c | 9 ++++----- 3 files changed, 18 insertions(+), 20 deletions(-) diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 1dd59abe541d..91f74e741aa2 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -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; } /* diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 996384672c73..12c98dfc31b1 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -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) - */ -#define MAX_ZONELISTS 2 -#else -#define MAX_ZONELISTS 1 + /* + * The NUMA zonelists are doubled because we need zonelists that + * restrict the allocations to a single node for __GFP_THISNODE. + */ + ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */ #endif + MAX_ZONELISTS +}; /* * This struct contains information about a zone in a zonelist. It is stored diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 2f6d30db4c94..e40e702ce919 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -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);