This makes memcg to depend on CONFIG_MMU.
==
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Using virt_array for memcg's node information.
Now, memcg allocates an array of pointer in the lengh of MAXNUMNODES
to hold pointers for per-node information.
This has 2 bad points
- struct mem_cgroup can be very big.
- need to access a pointer table for lookup zoneinfo.
This patch replaces memcg's nodeinfo with virt-array and do
direct access. With my config on x86-64, struct mem_cgroup's
size is changed from 4368->352.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
---
init/Kconfig | 2 +-
mm/memcontrol.c | 51 ++++++++++++++++-----------------------------------
2 files changed, 17 insertions(+), 36 deletions(-)
Index: mmotm-2.6.35-0719/init/Kconfig
===================================================================
--- mmotm-2.6.35-0719.orig/init/Kconfig
+++ mmotm-2.6.35-0719/init/Kconfig
@@ -555,7 +555,7 @@ config RESOURCE_COUNTERS
config CGROUP_MEM_RES_CTLR
bool "Memory Resource Controller for Control Groups"
- depends on CGROUPS && RESOURCE_COUNTERS
+ depends on CGROUPS && RESOURCE_COUNTERS && MMU
select MM_OWNER
help
Provides a memory resource controller that manages both anonymous
Index: mmotm-2.6.35-0719/mm/memcontrol.c
===================================================================
--- mmotm-2.6.35-0719.orig/mm/memcontrol.c
+++ mmotm-2.6.35-0719/mm/memcontrol.c
@@ -48,6 +48,7 @@
#include <linux/page_cgroup.h>
#include <linux/cpu.h>
#include <linux/oom.h>
+#include <linux/virt-array.h>
#include "internal.h"
#include <asm/uaccess.h>
@@ -119,11 +120,7 @@ struct mem_cgroup_per_zone {
struct mem_cgroup_per_node {
struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
-};
-
-struct mem_cgroup_lru_info {
- struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
-};
+} ____cacheline_aligned_in_smp;
/*
* Cgroups above their limits are maintained in a RB-Tree, independent of
@@ -205,7 +202,8 @@ struct mem_cgroup {
* Per cgroup active and inactive list, similar to the
* per zone LRU lists.
*/
- struct mem_cgroup_lru_info info;
+ struct mem_cgroup_per_node *nodes;
+ struct virt_array node_array;
/*
protect against reclaim related member.
@@ -344,7 +342,7 @@ static void drain_all_stock_async(void);
static struct mem_cgroup_per_zone *
mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
{
- return &mem->info.nodeinfo[nid]->zoneinfo[zid];
+ return &mem->nodes[nid].zoneinfo[zid];
}
struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem)
@@ -3944,27 +3942,14 @@ static int register_memsw_files(struct c
}
#endif
-static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
+static int init_mem_cgroup_node_info(struct mem_cgroup *mem, int node)
{
struct mem_cgroup_per_node *pn;
struct mem_cgroup_per_zone *mz;
enum lru_list l;
- int zone, tmp = node;
- /*
- * This routine is called against possible nodes.
- * But it's BUG to call kmalloc() against offline node.
- *
- * TODO: this routine can waste much memory for nodes which will
- * never be onlined. It's better to use memory hotplug callback
- * function.
- */
- if (!node_state(node, N_NORMAL_MEMORY))
- tmp = -1;
- pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
- if (!pn)
- return 1;
+ int zone;
- mem->info.nodeinfo[node] = pn;
+ pn = mem->nodes + node;
memset(pn, 0, sizeof(*pn));
for (zone = 0; zone < MAX_NR_ZONES; zone++) {
@@ -3978,11 +3963,6 @@ static int alloc_mem_cgroup_per_zone_inf
return 0;
}
-static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
-{
- kfree(mem->info.nodeinfo[node]);
-}
-
static struct mem_cgroup *mem_cgroup_alloc(void)
{
struct mem_cgroup *mem;
@@ -4022,13 +4002,10 @@ static struct mem_cgroup *mem_cgroup_all
static void __mem_cgroup_free(struct mem_cgroup *mem)
{
- int node;
-
mem_cgroup_remove_from_trees(mem);
free_css_id(&mem_cgroup_subsys, &mem->css);
- for_each_node_state(node, N_POSSIBLE)
- free_mem_cgroup_per_zone_info(mem, node);
+ destroy_varray(&mem->node_array);
free_percpu(mem->stat);
if (sizeof(struct mem_cgroup) < PAGE_SIZE)
@@ -4115,10 +4092,14 @@ mem_cgroup_create(struct cgroup_subsys *
if (!mem)
return ERR_PTR(error);
- for_each_node_state(node, N_POSSIBLE)
- if (alloc_mem_cgroup_per_zone_info(mem, node))
- goto free_out;
+ mem->nodes = create_varray(&mem->node_array,
+ sizeof(struct mem_cgroup_per_node), MAX_NUMNODES);
+ for_each_node_state(node, N_POSSIBLE) {
+ if (!alloc_varray_item(&mem->node_array, node))
+ goto free_out;
+ init_mem_cgroup_node_info(mem, node);
+ }
/* root ? */
if (cont->parent == NULL) {
int cpu;
--
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