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Commit 396faf03 authored by Mel Gorman's avatar Mel Gorman Committed by Linus Torvalds
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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: default avatarMel Gorman <mel@csn.ul.ie>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2a1e274a

include/linux/hugetlb.h

+2 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ static inline int is_vm_hugetlb_page(struct vm_area_struct *vma) 
}



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 @@ int hugetlb_reserve_pages(struct inode *inode, long from, long to); 
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;

include/linux/mempolicy.h

+3 −3
Original line number Diff line number Diff line
@@ -159,7 +159,7 @@ extern void mpol_fix_fork_child_flag(struct task_struct *p); 


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 @@ static inline void mpol_fix_fork_child_flag(struct task_struct *p) 
#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,

kernel/sysctl.c

+8 −0
Original line number Diff line number Diff line
@@ -826,6 +826,14 @@ static ctl_table vm_table[] = { 
		.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,

mm/hugetlb.c

+20 −3
Original line number Diff line number Diff line
@@ -27,6 +27,9 @@ unsigned long max_huge_pages; 
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 @@ static struct page *dequeue_huge_page(struct vm_area_struct *vma, 
{

	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 @@ static int alloc_fresh_huge_page(void) 
	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 @@ int hugetlb_sysctl_handler(struct ctl_table *table, int write, 
	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)

mm/mempolicy.c

+3 −2
Original line number Diff line number Diff line
@@ -1203,7 +1203,8 @@ static inline unsigned interleave_nid(struct mempolicy *pol, 


#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 @@ struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr) 
		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);

}