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-rw-r--r--mm/page_alloc.c59
1 files changed, 53 insertions, 6 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4bc66f6b771..62564e27b44 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1727,6 +1727,7 @@ void __init build_all_zonelists(void)
*/
#define PAGES_PER_WAITQUEUE 256
+#ifndef CONFIG_MEMORY_HOTPLUG
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
{
unsigned long size = 1;
@@ -1745,6 +1746,29 @@ static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
return max(size, 4UL);
}
+#else
+/*
+ * A zone's size might be changed by hot-add, so it is not possible to determine
+ * a suitable size for its wait_table. So we use the maximum size now.
+ *
+ * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
+ *
+ * i386 (preemption config) : 4096 x 16 = 64Kbyte.
+ * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
+ * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
+ *
+ * The maximum entries are prepared when a zone's memory is (512K + 256) pages
+ * or more by the traditional way. (See above). It equals:
+ *
+ * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
+ * ia64(16K page size) : = ( 8G + 4M)byte.
+ * powerpc (64K page size) : = (32G +16M)byte.
+ */
+static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
+{
+ return 4096UL;
+}
+#endif
/*
* This is an integer logarithm so that shifts can be used later
@@ -2010,10 +2034,11 @@ void __init setup_per_cpu_pageset(void)
#endif
static __meminit
-void zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
+int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
{
int i;
struct pglist_data *pgdat = zone->zone_pgdat;
+ size_t alloc_size;
/*
* The per-page waitqueue mechanism uses hashed waitqueues
@@ -2023,12 +2048,32 @@ void zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
wait_table_hash_nr_entries(zone_size_pages);
zone->wait_table_bits =
wait_table_bits(zone->wait_table_hash_nr_entries);
- zone->wait_table = (wait_queue_head_t *)
- alloc_bootmem_node(pgdat, zone->wait_table_hash_nr_entries
- * sizeof(wait_queue_head_t));
+ alloc_size = zone->wait_table_hash_nr_entries
+ * sizeof(wait_queue_head_t);
+
+ if (system_state == SYSTEM_BOOTING) {
+ zone->wait_table = (wait_queue_head_t *)
+ alloc_bootmem_node(pgdat, alloc_size);
+ } else {
+ /*
+ * This case means that a zone whose size was 0 gets new memory
+ * via memory hot-add.
+ * But it may be the case that a new node was hot-added. In
+ * this case vmalloc() will not be able to use this new node's
+ * memory - this wait_table must be initialized to use this new
+ * node itself as well.
+ * To use this new node's memory, further consideration will be
+ * necessary.
+ */
+ zone->wait_table = (wait_queue_head_t *)vmalloc(alloc_size);
+ }
+ if (!zone->wait_table)
+ return -ENOMEM;
for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
init_waitqueue_head(zone->wait_table + i);
+
+ return 0;
}
static __meminit void zone_pcp_init(struct zone *zone)
@@ -2055,8 +2100,10 @@ __meminit int init_currently_empty_zone(struct zone *zone,
unsigned long size)
{
struct pglist_data *pgdat = zone->zone_pgdat;
-
- zone_wait_table_init(zone, size);
+ int ret;
+ ret = zone_wait_table_init(zone, size);
+ if (ret)
+ return ret;
pgdat->nr_zones = zone_idx(zone) + 1;
zone->zone_start_pfn = zone_start_pfn;