linux/mm/page_cgroup.c
Fernando Luis Vazquez Cao 0753b0ef3b memcg: do not recalculate section unnecessarily in init_section_page_cgroup
In init_section_page_cgroup() the section a given pfn belongs to is
calculated at the top of the function and, despite the fact that the
pfn/section correspondence does not change, it is recalculated further
down the same function.  By computing this just once and reusing that
value we save some bytes in the object file and do not waste CPU cycles.

Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:04 -08:00

273 lines
6.1 KiB
C

#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/bootmem.h>
#include <linux/bit_spinlock.h>
#include <linux/page_cgroup.h>
#include <linux/hash.h>
#include <linux/slab.h>
#include <linux/memory.h>
#include <linux/vmalloc.h>
#include <linux/cgroup.h>
static void __meminit
__init_page_cgroup(struct page_cgroup *pc, unsigned long pfn)
{
pc->flags = 0;
pc->mem_cgroup = NULL;
pc->page = pfn_to_page(pfn);
}
static unsigned long total_usage;
#if !defined(CONFIG_SPARSEMEM)
void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
{
pgdat->node_page_cgroup = NULL;
}
struct page_cgroup *lookup_page_cgroup(struct page *page)
{
unsigned long pfn = page_to_pfn(page);
unsigned long offset;
struct page_cgroup *base;
base = NODE_DATA(page_to_nid(page))->node_page_cgroup;
if (unlikely(!base))
return NULL;
offset = pfn - NODE_DATA(page_to_nid(page))->node_start_pfn;
return base + offset;
}
static int __init alloc_node_page_cgroup(int nid)
{
struct page_cgroup *base, *pc;
unsigned long table_size;
unsigned long start_pfn, nr_pages, index;
start_pfn = NODE_DATA(nid)->node_start_pfn;
nr_pages = NODE_DATA(nid)->node_spanned_pages;
if (!nr_pages)
return 0;
table_size = sizeof(struct page_cgroup) * nr_pages;
base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
if (!base)
return -ENOMEM;
for (index = 0; index < nr_pages; index++) {
pc = base + index;
__init_page_cgroup(pc, start_pfn + index);
}
NODE_DATA(nid)->node_page_cgroup = base;
total_usage += table_size;
return 0;
}
void __init page_cgroup_init(void)
{
int nid, fail;
if (mem_cgroup_subsys.disabled)
return;
for_each_online_node(nid) {
fail = alloc_node_page_cgroup(nid);
if (fail)
goto fail;
}
printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
printk(KERN_INFO "please try cgroup_disable=memory option if you"
" don't want\n");
return;
fail:
printk(KERN_CRIT "allocation of page_cgroup was failed.\n");
printk(KERN_CRIT "please try cgroup_disable=memory boot option\n");
panic("Out of memory");
}
#else /* CONFIG_FLAT_NODE_MEM_MAP */
struct page_cgroup *lookup_page_cgroup(struct page *page)
{
unsigned long pfn = page_to_pfn(page);
struct mem_section *section = __pfn_to_section(pfn);
return section->page_cgroup + pfn;
}
/* __alloc_bootmem...() is protected by !slab_available() */
static int __init_refok init_section_page_cgroup(unsigned long pfn)
{
struct mem_section *section = __pfn_to_section(pfn);
struct page_cgroup *base, *pc;
unsigned long table_size;
int nid, index;
if (!section->page_cgroup) {
nid = page_to_nid(pfn_to_page(pfn));
table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
if (slab_is_available()) {
base = kmalloc_node(table_size, GFP_KERNEL, nid);
if (!base)
base = vmalloc_node(table_size, nid);
} else {
base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
table_size,
PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
}
} else {
/*
* We don't have to allocate page_cgroup again, but
* address of memmap may be changed. So, we have to initialize
* again.
*/
base = section->page_cgroup + pfn;
table_size = 0;
/* check address of memmap is changed or not. */
if (base->page == pfn_to_page(pfn))
return 0;
}
if (!base) {
printk(KERN_ERR "page cgroup allocation failure\n");
return -ENOMEM;
}
for (index = 0; index < PAGES_PER_SECTION; index++) {
pc = base + index;
__init_page_cgroup(pc, pfn + index);
}
section->page_cgroup = base - pfn;
total_usage += table_size;
return 0;
}
#ifdef CONFIG_MEMORY_HOTPLUG
void __free_page_cgroup(unsigned long pfn)
{
struct mem_section *ms;
struct page_cgroup *base;
ms = __pfn_to_section(pfn);
if (!ms || !ms->page_cgroup)
return;
base = ms->page_cgroup + pfn;
if (is_vmalloc_addr(base)) {
vfree(base);
ms->page_cgroup = NULL;
} else {
struct page *page = virt_to_page(base);
if (!PageReserved(page)) { /* Is bootmem ? */
kfree(base);
ms->page_cgroup = NULL;
}
}
}
int __meminit online_page_cgroup(unsigned long start_pfn,
unsigned long nr_pages,
int nid)
{
unsigned long start, end, pfn;
int fail = 0;
start = start_pfn & ~(PAGES_PER_SECTION - 1);
end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
if (!pfn_present(pfn))
continue;
fail = init_section_page_cgroup(pfn);
}
if (!fail)
return 0;
/* rollback */
for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
__free_page_cgroup(pfn);
return -ENOMEM;
}
int __meminit offline_page_cgroup(unsigned long start_pfn,
unsigned long nr_pages, int nid)
{
unsigned long start, end, pfn;
start = start_pfn & ~(PAGES_PER_SECTION - 1);
end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
__free_page_cgroup(pfn);
return 0;
}
static int __meminit page_cgroup_callback(struct notifier_block *self,
unsigned long action, void *arg)
{
struct memory_notify *mn = arg;
int ret = 0;
switch (action) {
case MEM_GOING_ONLINE:
ret = online_page_cgroup(mn->start_pfn,
mn->nr_pages, mn->status_change_nid);
break;
case MEM_OFFLINE:
offline_page_cgroup(mn->start_pfn,
mn->nr_pages, mn->status_change_nid);
break;
case MEM_CANCEL_ONLINE:
case MEM_GOING_OFFLINE:
break;
case MEM_ONLINE:
case MEM_CANCEL_OFFLINE:
break;
}
if (ret)
ret = notifier_from_errno(ret);
else
ret = NOTIFY_OK;
return ret;
}
#endif
void __init page_cgroup_init(void)
{
unsigned long pfn;
int fail = 0;
if (mem_cgroup_subsys.disabled)
return;
for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) {
if (!pfn_present(pfn))
continue;
fail = init_section_page_cgroup(pfn);
}
if (fail) {
printk(KERN_CRIT "try cgroup_disable=memory boot option\n");
panic("Out of memory");
} else {
hotplug_memory_notifier(page_cgroup_callback, 0);
}
printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
printk(KERN_INFO "please try cgroup_disable=memory option if you don't"
" want\n");
}
void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
{
return;
}
#endif