change zonelist order: zonelist order selection logic
Make zonelist creation policy selectable from sysctl/boot option v6. This patch makes NUMA's zonelist (of pgdat) order selectable. Available order are Default(automatic)/ Node-based / Zone-based. [Default Order] The kernel selects Node-based or Zone-based order automatically. [Node-based Order] This policy treats the locality of memory as the most important parameter. Zonelist order is created by each zone's locality. This means lower zones (ex. ZONE_DMA) can be used before higher zone (ex. ZONE_NORMAL) exhausion. IOW. ZONE_DMA will be in the middle of zonelist. current 2.6.21 kernel uses this. Pros. * A user can expect local memory as much as possible. Cons. * lower zone will be exhansted before higher zone. This may cause OOM_KILL. Maybe suitable if ZONE_DMA is relatively big and you never see OOM_KILL because of ZONE_DMA exhaution and you need the best locality. (example) assume 2 node NUMA. node(0) has ZONE_DMA/ZONE_NORMAL, node(1) has ZONE_NORMAL. *node(0)'s memory allocation order: node(0)'s NORMAL -> node(0)'s DMA -> node(1)'s NORMAL. *node(1)'s memory allocation order: node(1)'s NORMAL -> node(0)'s NORMAL -> node(0)'s DMA. [Zone-based order] This policy treats the zone type as the most important parameter. Zonelist order is created by zone-type order. This means lower zone never be used bofere higher zone exhaustion. IOW. ZONE_DMA will be always at the tail of zonelist. Pros. * OOM_KILL(bacause of lower zone) occurs only if the whole zones are exhausted. Cons. * memory locality may not be best. (example) assume 2 node NUMA. node(0) has ZONE_DMA/ZONE_NORMAL, node(1) has ZONE_NORMAL. *node(0)'s memory allocation order: node(0)'s NORMAL -> node(1)'s NORMAL -> node(0)'s DMA. *node(1)'s memory allocation order: node(1)'s NORMAL -> node(0)'s NORMAL -> node(0)'s DMA. bootoption "numa_zonelist_order=" and proc/sysctl is supporetd. command: %echo N > /proc/sys/vm/numa_zonelist_order Will rebuild zonelist in Node-based order. command: %echo Z > /proc/sys/vm/numa_zonelist_order Will rebuild zonelist in Zone-based order. Thanks to Lee Schermerhorn, he gives me much help and codes. [Lee.Schermerhorn@hp.com: add check_highest_zone to build_zonelists_in_zone_order] [akpm@linux-foundation.org: build fix] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@suse.de> Cc: "jesse.barnes@intel.com" <jesse.barnes@intel.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
KAMEZAWA Hiroyuki
committed by
Linus Torvalds
Linus Torvalds
parent
18a8bd949d
commit
f0c0b2b808
273
mm/page_alloc.c
273
mm/page_alloc.c
@ -1621,8 +1621,8 @@ void show_free_areas(void)
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*
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* Add all populated zones of a node to the zonelist.
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*/
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static int __meminit build_zonelists_node(pg_data_t *pgdat,
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struct zonelist *zonelist, int nr_zones, enum zone_type zone_type)
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static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
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int nr_zones, enum zone_type zone_type)
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{
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struct zone *zone;
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@ -1641,9 +1641,102 @@ static int __meminit build_zonelists_node(pg_data_t *pgdat,
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return nr_zones;
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}
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/*
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* zonelist_order:
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* 0 = automatic detection of better ordering.
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* 1 = order by ([node] distance, -zonetype)
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* 2 = order by (-zonetype, [node] distance)
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*
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* If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
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* the same zonelist. So only NUMA can configure this param.
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*/
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#define ZONELIST_ORDER_DEFAULT 0
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#define ZONELIST_ORDER_NODE 1
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#define ZONELIST_ORDER_ZONE 2
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/* zonelist order in the kernel.
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* set_zonelist_order() will set this to NODE or ZONE.
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*/
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static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
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static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
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#ifdef CONFIG_NUMA
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/* The value user specified ....changed by config */
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static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
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/* string for sysctl */
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#define NUMA_ZONELIST_ORDER_LEN 16
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char numa_zonelist_order[16] = "default";
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/*
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* interface for configure zonelist ordering.
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* command line option "numa_zonelist_order"
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* = "[dD]efault - default, automatic configuration.
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* = "[nN]ode - order by node locality, then by zone within node
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* = "[zZ]one - order by zone, then by locality within zone
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*/
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static int __parse_numa_zonelist_order(char *s)
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{
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if (*s == 'd' || *s == 'D') {
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user_zonelist_order = ZONELIST_ORDER_DEFAULT;
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} else if (*s == 'n' || *s == 'N') {
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user_zonelist_order = ZONELIST_ORDER_NODE;
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} else if (*s == 'z' || *s == 'Z') {
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user_zonelist_order = ZONELIST_ORDER_ZONE;
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} else {
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printk(KERN_WARNING
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"Ignoring invalid numa_zonelist_order value: "
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"%s\n", s);
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return -EINVAL;
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}
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return 0;
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}
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static __init int setup_numa_zonelist_order(char *s)
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{
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if (s)
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return __parse_numa_zonelist_order(s);
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return 0;
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}
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early_param("numa_zonelist_order", setup_numa_zonelist_order);
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/*
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* sysctl handler for numa_zonelist_order
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*/
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int numa_zonelist_order_handler(ctl_table *table, int write,
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struct file *file, void __user *buffer, size_t *length,
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loff_t *ppos)
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{
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char saved_string[NUMA_ZONELIST_ORDER_LEN];
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int ret;
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if (write)
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strncpy(saved_string, (char*)table->data,
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NUMA_ZONELIST_ORDER_LEN);
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ret = proc_dostring(table, write, file, buffer, length, ppos);
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if (ret)
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return ret;
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if (write) {
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int oldval = user_zonelist_order;
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if (__parse_numa_zonelist_order((char*)table->data)) {
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/*
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* bogus value. restore saved string
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*/
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strncpy((char*)table->data, saved_string,
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NUMA_ZONELIST_ORDER_LEN);
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user_zonelist_order = oldval;
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} else if (oldval != user_zonelist_order)
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build_all_zonelists();
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}
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return 0;
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}
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#define MAX_NODE_LOAD (num_online_nodes())
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static int __meminitdata node_load[MAX_NUMNODES];
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static int node_load[MAX_NUMNODES];
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/**
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* find_next_best_node - find the next node that should appear in a given node's fallback list
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* @node: node whose fallback list we're appending
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@ -1658,7 +1751,7 @@ static int __meminitdata node_load[MAX_NUMNODES];
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* on them otherwise.
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* It returns -1 if no node is found.
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*/
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static int __meminit find_next_best_node(int node, nodemask_t *used_node_mask)
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static int find_next_best_node(int node, nodemask_t *used_node_mask)
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{
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int n, val;
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int min_val = INT_MAX;
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@ -1704,13 +1797,129 @@ static int __meminit find_next_best_node(int node, nodemask_t *used_node_mask)
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return best_node;
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}
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static void __meminit build_zonelists(pg_data_t *pgdat)
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/*
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* Build zonelists ordered by node and zones within node.
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* This results in maximum locality--normal zone overflows into local
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* DMA zone, if any--but risks exhausting DMA zone.
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*/
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static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
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{
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int j, node, local_node;
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enum zone_type i;
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int prev_node, load;
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int j;
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struct zonelist *zonelist;
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for (i = 0; i < MAX_NR_ZONES; i++) {
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zonelist = pgdat->node_zonelists + i;
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for (j = 0; zonelist->zones[j] != NULL; j++)
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;
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j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
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zonelist->zones[j] = NULL;
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}
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}
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/*
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* Build zonelists ordered by zone and nodes within zones.
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* This results in conserving DMA zone[s] until all Normal memory is
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* exhausted, but results in overflowing to remote node while memory
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* may still exist in local DMA zone.
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*/
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static int node_order[MAX_NUMNODES];
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static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
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{
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enum zone_type i;
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int pos, j, node;
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int zone_type; /* needs to be signed */
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struct zone *z;
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struct zonelist *zonelist;
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for (i = 0; i < MAX_NR_ZONES; i++) {
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zonelist = pgdat->node_zonelists + i;
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pos = 0;
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for (zone_type = i; zone_type >= 0; zone_type--) {
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for (j = 0; j < nr_nodes; j++) {
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node = node_order[j];
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z = &NODE_DATA(node)->node_zones[zone_type];
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if (populated_zone(z)) {
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zonelist->zones[pos++] = z;
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check_highest_zone(zone_type);
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}
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}
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}
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zonelist->zones[pos] = NULL;
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}
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}
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static int default_zonelist_order(void)
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{
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int nid, zone_type;
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unsigned long low_kmem_size,total_size;
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struct zone *z;
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int average_size;
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/*
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* ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
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* If they are really small and used heavily, the system can fall
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* into OOM very easily.
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* This function detect ZONE_DMA/DMA32 size and confgigures zone order.
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*/
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/* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
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low_kmem_size = 0;
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total_size = 0;
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for_each_online_node(nid) {
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for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
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z = &NODE_DATA(nid)->node_zones[zone_type];
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if (populated_zone(z)) {
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if (zone_type < ZONE_NORMAL)
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low_kmem_size += z->present_pages;
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total_size += z->present_pages;
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}
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}
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}
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if (!low_kmem_size || /* there are no DMA area. */
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low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
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return ZONELIST_ORDER_NODE;
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/*
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* look into each node's config.
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* If there is a node whose DMA/DMA32 memory is very big area on
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* local memory, NODE_ORDER may be suitable.
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*/
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average_size = total_size / (num_online_nodes() + 1);
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for_each_online_node(nid) {
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low_kmem_size = 0;
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total_size = 0;
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for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
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z = &NODE_DATA(nid)->node_zones[zone_type];
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if (populated_zone(z)) {
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if (zone_type < ZONE_NORMAL)
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low_kmem_size += z->present_pages;
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total_size += z->present_pages;
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}
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}
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if (low_kmem_size &&
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total_size > average_size && /* ignore small node */
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low_kmem_size > total_size * 70/100)
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return ZONELIST_ORDER_NODE;
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}
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return ZONELIST_ORDER_ZONE;
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}
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static void set_zonelist_order(void)
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{
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if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
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current_zonelist_order = default_zonelist_order();
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else
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current_zonelist_order = user_zonelist_order;
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}
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static void build_zonelists(pg_data_t *pgdat)
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{
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int j, node, load;
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enum zone_type i;
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nodemask_t used_mask;
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int local_node, prev_node;
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struct zonelist *zonelist;
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int order = current_zonelist_order;
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/* initialize zonelists */
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for (i = 0; i < MAX_NR_ZONES; i++) {
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@ -1723,6 +1932,11 @@ static void __meminit build_zonelists(pg_data_t *pgdat)
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load = num_online_nodes();
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prev_node = local_node;
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nodes_clear(used_mask);
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memset(node_load, 0, sizeof(node_load));
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memset(node_order, 0, sizeof(node_order));
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j = 0;
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while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
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int distance = node_distance(local_node, node);
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@ -1738,23 +1952,25 @@ static void __meminit build_zonelists(pg_data_t *pgdat)
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* So adding penalty to the first node in same
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* distance group to make it round-robin.
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*/
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if (distance != node_distance(local_node, prev_node))
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node_load[node] += load;
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node_load[node] = load;
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prev_node = node;
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load--;
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for (i = 0; i < MAX_NR_ZONES; i++) {
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zonelist = pgdat->node_zonelists + i;
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for (j = 0; zonelist->zones[j] != NULL; j++);
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if (order == ZONELIST_ORDER_NODE)
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build_zonelists_in_node_order(pgdat, node);
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else
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node_order[j++] = node; /* remember order */
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}
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j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
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zonelist->zones[j] = NULL;
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}
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if (order == ZONELIST_ORDER_ZONE) {
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/* calculate node order -- i.e., DMA last! */
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build_zonelists_in_zone_order(pgdat, j);
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}
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}
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/* Construct the zonelist performance cache - see further mmzone.h */
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static void __meminit build_zonelist_cache(pg_data_t *pgdat)
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static void build_zonelist_cache(pg_data_t *pgdat)
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{
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int i;
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@ -1771,9 +1987,15 @@ static void __meminit build_zonelist_cache(pg_data_t *pgdat)
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}
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}
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#else /* CONFIG_NUMA */
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static void __meminit build_zonelists(pg_data_t *pgdat)
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static void set_zonelist_order(void)
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{
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current_zonelist_order = ZONELIST_ORDER_ZONE;
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}
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static void build_zonelists(pg_data_t *pgdat)
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{
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int node, local_node;
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enum zone_type i,j;
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@ -1809,7 +2031,7 @@ static void __meminit build_zonelists(pg_data_t *pgdat)
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}
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/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
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static void __meminit build_zonelist_cache(pg_data_t *pgdat)
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static void build_zonelist_cache(pg_data_t *pgdat)
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{
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int i;
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@ -1820,7 +2042,7 @@ static void __meminit build_zonelist_cache(pg_data_t *pgdat)
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#endif /* CONFIG_NUMA */
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/* return values int ....just for stop_machine_run() */
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static int __meminit __build_all_zonelists(void *dummy)
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static int __build_all_zonelists(void *dummy)
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{
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int nid;
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@ -1831,8 +2053,10 @@ static int __meminit __build_all_zonelists(void *dummy)
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return 0;
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}
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void __meminit build_all_zonelists(void)
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void build_all_zonelists(void)
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{
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set_zonelist_order();
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if (system_state == SYSTEM_BOOTING) {
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__build_all_zonelists(NULL);
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cpuset_init_current_mems_allowed();
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@ -1843,8 +2067,13 @@ void __meminit build_all_zonelists(void)
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/* cpuset refresh routine should be here */
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}
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vm_total_pages = nr_free_pagecache_pages();
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printk("Built %i zonelists. Total pages: %ld\n",
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num_online_nodes(), vm_total_pages);
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printk("Built %i zonelists in %s order. Total pages: %ld\n",
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num_online_nodes(),
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zonelist_order_name[current_zonelist_order],
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vm_total_pages);
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#ifdef CONFIG_NUMA
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printk("Policy zone: %s\n", zone_names[policy_zone]);
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#endif
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}
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/*
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Block a user