linux/mm/hugetlb_sysctl.c

135 lines
3.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* HugeTLB sysfs interfaces.
* (C) Nadia Yvette Chambers, April 2004
*/
#include <linux/sysctl.h>
#include "hugetlb_internal.h"
#ifdef CONFIG_SYSCTL
static int proc_hugetlb_doulongvec_minmax(const struct ctl_table *table, int write,
void *buffer, size_t *length,
loff_t *ppos, unsigned long *out)
{
struct ctl_table dup_table;
/*
* In order to avoid races with __do_proc_doulongvec_minmax(), we
* can duplicate the @table and alter the duplicate of it.
*/
dup_table = *table;
dup_table.data = out;
return proc_doulongvec_minmax(&dup_table, write, buffer, length, ppos);
}
static int hugetlb_sysctl_handler_common(bool obey_mempolicy,
const struct ctl_table *table, int write,
void *buffer, size_t *length, loff_t *ppos)
{
struct hstate *h = &default_hstate;
unsigned long tmp = h->max_huge_pages;
int ret;
if (!hugepages_supported())
return -EOPNOTSUPP;
ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos,
&tmp);
if (ret)
goto out;
if (write)
ret = __nr_hugepages_store_common(obey_mempolicy, h,
NUMA_NO_NODE, tmp, *length);
out:
return ret;
}
static int hugetlb_sysctl_handler(const struct ctl_table *table, int write,
void *buffer, size_t *length, loff_t *ppos)
{
return hugetlb_sysctl_handler_common(false, table, write,
buffer, length, ppos);
}
#ifdef CONFIG_NUMA
static int hugetlb_mempolicy_sysctl_handler(const struct ctl_table *table, int write,
void *buffer, size_t *length, loff_t *ppos)
{
return hugetlb_sysctl_handler_common(true, table, write,
buffer, length, ppos);
}
#endif /* CONFIG_NUMA */
static int hugetlb_overcommit_handler(const struct ctl_table *table, int write,
void *buffer, size_t *length, loff_t *ppos)
{
struct hstate *h = &default_hstate;
unsigned long tmp;
int ret;
if (!hugepages_supported())
return -EOPNOTSUPP;
tmp = h->nr_overcommit_huge_pages;
if (write && hstate_is_gigantic_no_runtime(h))
return -EINVAL;
ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos,
&tmp);
if (ret)
goto out;
if (write) {
spin_lock_irq(&hugetlb_lock);
h->nr_overcommit_huge_pages = tmp;
spin_unlock_irq(&hugetlb_lock);
}
out:
return ret;
}
static const struct ctl_table hugetlb_table[] = {
{
.procname = "nr_hugepages",
.data = NULL,
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = hugetlb_sysctl_handler,
},
#ifdef CONFIG_NUMA
{
.procname = "nr_hugepages_mempolicy",
.data = NULL,
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = &hugetlb_mempolicy_sysctl_handler,
},
#endif
{
.procname = "hugetlb_shm_group",
.data = &sysctl_hugetlb_shm_group,
.maxlen = sizeof(gid_t),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "nr_overcommit_hugepages",
.data = NULL,
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = hugetlb_overcommit_handler,
},
};
void __init hugetlb_sysctl_init(void)
{
register_sysctl_init("vm", hugetlb_table);
}
#endif /* CONFIG_SYSCTL */