hugetlb: new sysfs interface

Provide new hugepages user APIs that are more suited to multiple hstates
in sysfs.  There is a new directory, /sys/kernel/hugepages.  Underneath
that directory there will be a directory per-supported hugepage size,
e.g.:

/sys/kernel/hugepages/hugepages-64kB
/sys/kernel/hugepages/hugepages-16384kB
/sys/kernel/hugepages/hugepages-16777216kB

corresponding to 64k, 16m and 16g respectively.  Within each
hugepages-size directory there are a number of files, corresponding to the
tracked counters in the hstate, e.g.:

/sys/kernel/hugepages/hugepages-64/nr_hugepages
/sys/kernel/hugepages/hugepages-64/nr_overcommit_hugepages
/sys/kernel/hugepages/hugepages-64/free_hugepages
/sys/kernel/hugepages/hugepages-64/resv_hugepages
/sys/kernel/hugepages/hugepages-64/surplus_hugepages

Of these files, the first two are read-write and the latter three are
read-only.  The size of the hugepage being manipulated is trivially
deducible from the enclosing directory and is always expressed in kB (to
match meminfo).

[dave@linux.vnet.ibm.com: fix build]
[nacc@us.ibm.com: hugetlb: hang off of /sys/kernel/mm rather than /sys/kernel]
[nacc@us.ibm.com: hugetlb: remove CONFIG_SYSFS dependency]
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Nishanth Aravamudan 2008-07-23 21:27:44 -07:00 committed by Linus Torvalds
parent a137e1cc6d
commit a343787016
4 changed files with 262 additions and 66 deletions

View file

@ -14,6 +14,7 @@
#include <linux/mempolicy.h>
#include <linux/cpuset.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <asm/page.h>
#include <asm/pgtable.h>
@ -942,72 +943,6 @@ static void __init report_hugepages(void)
}
}
static int __init hugetlb_init(void)
{
BUILD_BUG_ON(HPAGE_SHIFT == 0);
if (!size_to_hstate(HPAGE_SIZE)) {
hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
parsed_hstate->max_huge_pages = default_hstate_max_huge_pages;
}
default_hstate_idx = size_to_hstate(HPAGE_SIZE) - hstates;
hugetlb_init_hstates();
report_hugepages();
return 0;
}
module_init(hugetlb_init);
/* Should be called on processing a hugepagesz=... option */
void __init hugetlb_add_hstate(unsigned order)
{
struct hstate *h;
if (size_to_hstate(PAGE_SIZE << order)) {
printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n");
return;
}
BUG_ON(max_hstate >= HUGE_MAX_HSTATE);
BUG_ON(order == 0);
h = &hstates[max_hstate++];
h->order = order;
h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
hugetlb_init_one_hstate(h);
parsed_hstate = h;
}
static int __init hugetlb_setup(char *s)
{
unsigned long *mhp;
/*
* !max_hstate means we haven't parsed a hugepagesz= parameter yet,
* so this hugepages= parameter goes to the "default hstate".
*/
if (!max_hstate)
mhp = &default_hstate_max_huge_pages;
else
mhp = &parsed_hstate->max_huge_pages;
if (sscanf(s, "%lu", mhp) <= 0)
*mhp = 0;
return 1;
}
__setup("hugepages=", hugetlb_setup);
static unsigned int cpuset_mems_nr(unsigned int *array)
{
int node;
unsigned int nr = 0;
for_each_node_mask(node, cpuset_current_mems_allowed)
nr += array[node];
return nr;
}
#ifdef CONFIG_SYSCTL
#ifdef CONFIG_HIGHMEM
static void try_to_free_low(struct hstate *h, unsigned long count)
@ -1105,6 +1040,227 @@ out:
return ret;
}
#define HSTATE_ATTR_RO(_name) \
static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
#define HSTATE_ATTR(_name) \
static struct kobj_attribute _name##_attr = \
__ATTR(_name, 0644, _name##_show, _name##_store)
static struct kobject *hugepages_kobj;
static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
static struct hstate *kobj_to_hstate(struct kobject *kobj)
{
int i;
for (i = 0; i < HUGE_MAX_HSTATE; i++)
if (hstate_kobjs[i] == kobj)
return &hstates[i];
BUG();
return NULL;
}
static ssize_t nr_hugepages_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct hstate *h = kobj_to_hstate(kobj);
return sprintf(buf, "%lu\n", h->nr_huge_pages);
}
static ssize_t nr_hugepages_store(struct kobject *kobj,
struct kobj_attribute *attr, const char *buf, size_t count)
{
int err;
unsigned long input;
struct hstate *h = kobj_to_hstate(kobj);
err = strict_strtoul(buf, 10, &input);
if (err)
return 0;
h->max_huge_pages = set_max_huge_pages(h, input);
return count;
}
HSTATE_ATTR(nr_hugepages);
static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct hstate *h = kobj_to_hstate(kobj);
return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages);
}
static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj,
struct kobj_attribute *attr, const char *buf, size_t count)
{
int err;
unsigned long input;
struct hstate *h = kobj_to_hstate(kobj);
err = strict_strtoul(buf, 10, &input);
if (err)
return 0;
spin_lock(&hugetlb_lock);
h->nr_overcommit_huge_pages = input;
spin_unlock(&hugetlb_lock);
return count;
}
HSTATE_ATTR(nr_overcommit_hugepages);
static ssize_t free_hugepages_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct hstate *h = kobj_to_hstate(kobj);
return sprintf(buf, "%lu\n", h->free_huge_pages);
}
HSTATE_ATTR_RO(free_hugepages);
static ssize_t resv_hugepages_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct hstate *h = kobj_to_hstate(kobj);
return sprintf(buf, "%lu\n", h->resv_huge_pages);
}
HSTATE_ATTR_RO(resv_hugepages);
static ssize_t surplus_hugepages_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct hstate *h = kobj_to_hstate(kobj);
return sprintf(buf, "%lu\n", h->surplus_huge_pages);
}
HSTATE_ATTR_RO(surplus_hugepages);
static struct attribute *hstate_attrs[] = {
&nr_hugepages_attr.attr,
&nr_overcommit_hugepages_attr.attr,
&free_hugepages_attr.attr,
&resv_hugepages_attr.attr,
&surplus_hugepages_attr.attr,
NULL,
};
static struct attribute_group hstate_attr_group = {
.attrs = hstate_attrs,
};
static int __init hugetlb_sysfs_add_hstate(struct hstate *h)
{
int retval;
hstate_kobjs[h - hstates] = kobject_create_and_add(h->name,
hugepages_kobj);
if (!hstate_kobjs[h - hstates])
return -ENOMEM;
retval = sysfs_create_group(hstate_kobjs[h - hstates],
&hstate_attr_group);
if (retval)
kobject_put(hstate_kobjs[h - hstates]);
return retval;
}
static void __init hugetlb_sysfs_init(void)
{
struct hstate *h;
int err;
hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj);
if (!hugepages_kobj)
return;
for_each_hstate(h) {
err = hugetlb_sysfs_add_hstate(h);
if (err)
printk(KERN_ERR "Hugetlb: Unable to add hstate %s",
h->name);
}
}
static void __exit hugetlb_exit(void)
{
struct hstate *h;
for_each_hstate(h) {
kobject_put(hstate_kobjs[h - hstates]);
}
kobject_put(hugepages_kobj);
}
module_exit(hugetlb_exit);
static int __init hugetlb_init(void)
{
BUILD_BUG_ON(HPAGE_SHIFT == 0);
if (!size_to_hstate(HPAGE_SIZE)) {
hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
parsed_hstate->max_huge_pages = default_hstate_max_huge_pages;
}
default_hstate_idx = size_to_hstate(HPAGE_SIZE) - hstates;
hugetlb_init_hstates();
report_hugepages();
hugetlb_sysfs_init();
return 0;
}
module_init(hugetlb_init);
/* Should be called on processing a hugepagesz=... option */
void __init hugetlb_add_hstate(unsigned order)
{
struct hstate *h;
if (size_to_hstate(PAGE_SIZE << order)) {
printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n");
return;
}
BUG_ON(max_hstate >= HUGE_MAX_HSTATE);
BUG_ON(order == 0);
h = &hstates[max_hstate++];
h->order = order;
h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
huge_page_size(h)/1024);
hugetlb_init_one_hstate(h);
parsed_hstate = h;
}
static int __init hugetlb_setup(char *s)
{
unsigned long *mhp;
/*
* !max_hstate means we haven't parsed a hugepagesz= parameter yet,
* so this hugepages= parameter goes to the "default hstate".
*/
if (!max_hstate)
mhp = &default_hstate_max_huge_pages;
else
mhp = &parsed_hstate->max_huge_pages;
if (sscanf(s, "%lu", mhp) <= 0)
*mhp = 0;
return 1;
}
__setup("hugepages=", hugetlb_setup);
static unsigned int cpuset_mems_nr(unsigned int *array)
{
int node;
unsigned int nr = 0;
for_each_node_mask(node, cpuset_current_mems_allowed)
nr += array[node];
return nr;
}
int hugetlb_sysctl_handler(struct ctl_table *table, int write,
struct file *file, void __user *buffer,
size_t *length, loff_t *ppos)