Allow huge page allocations to use GFP_HIGH_MOVABLE
Huge pages are not movable so are not allocated from ZONE_MOVABLE. However,
as ZONE_MOVABLE will always have pages that can be migrated or reclaimed, it
can be used to satisfy hugepage allocations even when the system has been
running a long time. This allows an administrator to resize the hugepage pool
at runtime depending on the size of ZONE_MOVABLE.
This patch adds a new sysctl called hugepages_treat_as_movable. When a
non-zero value is written to it, future allocations for the huge page pool
will use ZONE_MOVABLE. Despite huge pages being non-movable, we do not
introduce additional external fragmentation of note as huge pages are always
the largest contiguous block we care about.
[akpm@linux-foundation.org: various fixes]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 2c13715..49b7053 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -15,6 +15,7 @@
}
int hugetlb_sysctl_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *);
+int hugetlb_treat_movable_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *);
int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *, struct vm_area_struct *);
int follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *, struct page **, struct vm_area_struct **, unsigned long *, int *, int);
void unmap_hugepage_range(struct vm_area_struct *, unsigned long, unsigned long);
@@ -29,6 +30,7 @@
void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed);
extern unsigned long max_huge_pages;
+extern unsigned long hugepages_treat_as_movable;
extern const unsigned long hugetlb_zero, hugetlb_infinity;
extern int sysctl_hugetlb_shm_group;
diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index daabb3a..e147cf5 100644
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -159,7 +159,7 @@
extern struct mempolicy default_policy;
extern struct zonelist *huge_zonelist(struct vm_area_struct *vma,
- unsigned long addr);
+ unsigned long addr, gfp_t gfp_flags);
extern unsigned slab_node(struct mempolicy *policy);
extern enum zone_type policy_zone;
@@ -256,9 +256,9 @@
#define set_cpuset_being_rebound(x) do {} while (0)
static inline struct zonelist *huge_zonelist(struct vm_area_struct *vma,
- unsigned long addr)
+ unsigned long addr, gfp_t gfp_flags)
{
- return NODE_DATA(0)->node_zonelists + gfp_zone(GFP_HIGHUSER);
+ return NODE_DATA(0)->node_zonelists + gfp_zone(gfp_flags);
}
static inline int do_migrate_pages(struct mm_struct *mm,
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 2ce7acf..48dae07 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -826,6 +826,14 @@
.mode = 0644,
.proc_handler = &proc_dointvec,
},
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "hugepages_treat_as_movable",
+ .data = &hugepages_treat_as_movable,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &hugetlb_treat_movable_handler,
+ },
#endif
{
.ctl_name = VM_LOWMEM_RESERVE_RATIO,
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index acc0fb3..5898067 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -27,6 +27,9 @@
static struct list_head hugepage_freelists[MAX_NUMNODES];
static unsigned int nr_huge_pages_node[MAX_NUMNODES];
static unsigned int free_huge_pages_node[MAX_NUMNODES];
+static gfp_t htlb_alloc_mask = GFP_HIGHUSER;
+unsigned long hugepages_treat_as_movable;
+
/*
* Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages
*/
@@ -68,12 +71,13 @@
{
int nid;
struct page *page = NULL;
- struct zonelist *zonelist = huge_zonelist(vma, address);
+ struct zonelist *zonelist = huge_zonelist(vma, address,
+ htlb_alloc_mask);
struct zone **z;
for (z = zonelist->zones; *z; z++) {
nid = zone_to_nid(*z);
- if (cpuset_zone_allowed_softwall(*z, GFP_HIGHUSER) &&
+ if (cpuset_zone_allowed_softwall(*z, htlb_alloc_mask) &&
!list_empty(&hugepage_freelists[nid]))
break;
}
@@ -113,7 +117,7 @@
prev_nid = nid;
spin_unlock(&nid_lock);
- page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN,
+ page = alloc_pages_node(nid, htlb_alloc_mask|__GFP_COMP|__GFP_NOWARN,
HUGETLB_PAGE_ORDER);
if (page) {
set_compound_page_dtor(page, free_huge_page);
@@ -263,6 +267,19 @@
max_huge_pages = set_max_huge_pages(max_huge_pages);
return 0;
}
+
+int hugetlb_treat_movable_handler(struct ctl_table *table, int write,
+ struct file *file, void __user *buffer,
+ size_t *length, loff_t *ppos)
+{
+ proc_dointvec(table, write, file, buffer, length, ppos);
+ if (hugepages_treat_as_movable)
+ htlb_alloc_mask = GFP_HIGHUSER_MOVABLE;
+ else
+ htlb_alloc_mask = GFP_HIGHUSER;
+ return 0;
+}
+
#endif /* CONFIG_SYSCTL */
int hugetlb_report_meminfo(char *buf)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 4c0f999..9f4e9b9 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1203,7 +1203,8 @@
#ifdef CONFIG_HUGETLBFS
/* Return a zonelist suitable for a huge page allocation. */
-struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr)
+struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
+ gfp_t gfp_flags)
{
struct mempolicy *pol = get_vma_policy(current, vma, addr);
@@ -1211,7 +1212,7 @@
unsigned nid;
nid = interleave_nid(pol, vma, addr, HPAGE_SHIFT);
- return NODE_DATA(nid)->node_zonelists + gfp_zone(GFP_HIGHUSER);
+ return NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_flags);
}
return zonelist_policy(GFP_HIGHUSER, pol);
}