linux/mm/sparse.c
Yinghai Lu 99ab7b1944 mm: sparse: fix usemap allocation above node descriptor section
After commit f5bf18fa22 ("bootmem/sparsemem: remove limit constraint
in alloc_bootmem_section"), usemap allocations may easily be placed
outside the optimal section that holds the node descriptor, even if
there is space available in that section.  This results in unnecessary
hotplug dependencies that need to have the node unplugged before the
section holding the usemap.

The reason is that the bootmem allocator doesn't guarantee a linear
search starting from the passed allocation goal but may start out at a
much higher address absent an upper limit.

Fix this by trying the allocation with the limit at the section end,
then retry without if that fails.  This keeps the fix from f5bf18fa22
of not panicking if the allocation does not fit in the section, but
still makes sure to try to stay within the section at first.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>	[3.3.x, 3.4.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-11 16:04:49 -07:00

800 lines
20 KiB
C

/*
* sparse memory mappings.
*/
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/mmzone.h>
#include <linux/bootmem.h>
#include <linux/highmem.h>
#include <linux/export.h>
#include <linux/spinlock.h>
#include <linux/vmalloc.h>
#include "internal.h"
#include <asm/dma.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
/*
* Permanent SPARSEMEM data:
*
* 1) mem_section - memory sections, mem_map's for valid memory
*/
#ifdef CONFIG_SPARSEMEM_EXTREME
struct mem_section *mem_section[NR_SECTION_ROOTS]
____cacheline_internodealigned_in_smp;
#else
struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
____cacheline_internodealigned_in_smp;
#endif
EXPORT_SYMBOL(mem_section);
#ifdef NODE_NOT_IN_PAGE_FLAGS
/*
* If we did not store the node number in the page then we have to
* do a lookup in the section_to_node_table in order to find which
* node the page belongs to.
*/
#if MAX_NUMNODES <= 256
static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
#else
static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
#endif
int page_to_nid(const struct page *page)
{
return section_to_node_table[page_to_section(page)];
}
EXPORT_SYMBOL(page_to_nid);
static void set_section_nid(unsigned long section_nr, int nid)
{
section_to_node_table[section_nr] = nid;
}
#else /* !NODE_NOT_IN_PAGE_FLAGS */
static inline void set_section_nid(unsigned long section_nr, int nid)
{
}
#endif
#ifdef CONFIG_SPARSEMEM_EXTREME
static struct mem_section noinline __init_refok *sparse_index_alloc(int nid)
{
struct mem_section *section = NULL;
unsigned long array_size = SECTIONS_PER_ROOT *
sizeof(struct mem_section);
if (slab_is_available()) {
if (node_state(nid, N_HIGH_MEMORY))
section = kmalloc_node(array_size, GFP_KERNEL, nid);
else
section = kmalloc(array_size, GFP_KERNEL);
} else
section = alloc_bootmem_node(NODE_DATA(nid), array_size);
if (section)
memset(section, 0, array_size);
return section;
}
static int __meminit sparse_index_init(unsigned long section_nr, int nid)
{
static DEFINE_SPINLOCK(index_init_lock);
unsigned long root = SECTION_NR_TO_ROOT(section_nr);
struct mem_section *section;
int ret = 0;
if (mem_section[root])
return -EEXIST;
section = sparse_index_alloc(nid);
if (!section)
return -ENOMEM;
/*
* This lock keeps two different sections from
* reallocating for the same index
*/
spin_lock(&index_init_lock);
if (mem_section[root]) {
ret = -EEXIST;
goto out;
}
mem_section[root] = section;
out:
spin_unlock(&index_init_lock);
return ret;
}
#else /* !SPARSEMEM_EXTREME */
static inline int sparse_index_init(unsigned long section_nr, int nid)
{
return 0;
}
#endif
/*
* Although written for the SPARSEMEM_EXTREME case, this happens
* to also work for the flat array case because
* NR_SECTION_ROOTS==NR_MEM_SECTIONS.
*/
int __section_nr(struct mem_section* ms)
{
unsigned long root_nr;
struct mem_section* root;
for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
if (!root)
continue;
if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
break;
}
return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
}
/*
* During early boot, before section_mem_map is used for an actual
* mem_map, we use section_mem_map to store the section's NUMA
* node. This keeps us from having to use another data structure. The
* node information is cleared just before we store the real mem_map.
*/
static inline unsigned long sparse_encode_early_nid(int nid)
{
return (nid << SECTION_NID_SHIFT);
}
static inline int sparse_early_nid(struct mem_section *section)
{
return (section->section_mem_map >> SECTION_NID_SHIFT);
}
/* Validate the physical addressing limitations of the model */
void __meminit mminit_validate_memmodel_limits(unsigned long *start_pfn,
unsigned long *end_pfn)
{
unsigned long max_sparsemem_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT);
/*
* Sanity checks - do not allow an architecture to pass
* in larger pfns than the maximum scope of sparsemem:
*/
if (*start_pfn > max_sparsemem_pfn) {
mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
"Start of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
*start_pfn, *end_pfn, max_sparsemem_pfn);
WARN_ON_ONCE(1);
*start_pfn = max_sparsemem_pfn;
*end_pfn = max_sparsemem_pfn;
} else if (*end_pfn > max_sparsemem_pfn) {
mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
"End of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
*start_pfn, *end_pfn, max_sparsemem_pfn);
WARN_ON_ONCE(1);
*end_pfn = max_sparsemem_pfn;
}
}
/* Record a memory area against a node. */
void __init memory_present(int nid, unsigned long start, unsigned long end)
{
unsigned long pfn;
start &= PAGE_SECTION_MASK;
mminit_validate_memmodel_limits(&start, &end);
for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
unsigned long section = pfn_to_section_nr(pfn);
struct mem_section *ms;
sparse_index_init(section, nid);
set_section_nid(section, nid);
ms = __nr_to_section(section);
if (!ms->section_mem_map)
ms->section_mem_map = sparse_encode_early_nid(nid) |
SECTION_MARKED_PRESENT;
}
}
/*
* Only used by the i386 NUMA architecures, but relatively
* generic code.
*/
unsigned long __init node_memmap_size_bytes(int nid, unsigned long start_pfn,
unsigned long end_pfn)
{
unsigned long pfn;
unsigned long nr_pages = 0;
mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
if (nid != early_pfn_to_nid(pfn))
continue;
if (pfn_present(pfn))
nr_pages += PAGES_PER_SECTION;
}
return nr_pages * sizeof(struct page);
}
/*
* Subtle, we encode the real pfn into the mem_map such that
* the identity pfn - section_mem_map will return the actual
* physical page frame number.
*/
static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
{
return (unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
}
/*
* Decode mem_map from the coded memmap
*/
struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
{
/* mask off the extra low bits of information */
coded_mem_map &= SECTION_MAP_MASK;
return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
}
static int __meminit sparse_init_one_section(struct mem_section *ms,
unsigned long pnum, struct page *mem_map,
unsigned long *pageblock_bitmap)
{
if (!present_section(ms))
return -EINVAL;
ms->section_mem_map &= ~SECTION_MAP_MASK;
ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
SECTION_HAS_MEM_MAP;
ms->pageblock_flags = pageblock_bitmap;
return 1;
}
unsigned long usemap_size(void)
{
unsigned long size_bytes;
size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8;
size_bytes = roundup(size_bytes, sizeof(unsigned long));
return size_bytes;
}
#ifdef CONFIG_MEMORY_HOTPLUG
static unsigned long *__kmalloc_section_usemap(void)
{
return kmalloc(usemap_size(), GFP_KERNEL);
}
#endif /* CONFIG_MEMORY_HOTPLUG */
#ifdef CONFIG_MEMORY_HOTREMOVE
static unsigned long * __init
sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
unsigned long size)
{
unsigned long goal, limit;
unsigned long *p;
int nid;
/*
* A page may contain usemaps for other sections preventing the
* page being freed and making a section unremovable while
* other sections referencing the usemap retmain active. Similarly,
* a pgdat can prevent a section being removed. If section A
* contains a pgdat and section B contains the usemap, both
* sections become inter-dependent. This allocates usemaps
* from the same section as the pgdat where possible to avoid
* this problem.
*/
goal = __pa(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT);
limit = goal + (1UL << PA_SECTION_SHIFT);
nid = early_pfn_to_nid(goal >> PAGE_SHIFT);
again:
p = ___alloc_bootmem_node_nopanic(NODE_DATA(nid), size,
SMP_CACHE_BYTES, goal, limit);
if (!p && limit) {
limit = 0;
goto again;
}
return p;
}
static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
{
unsigned long usemap_snr, pgdat_snr;
static unsigned long old_usemap_snr = NR_MEM_SECTIONS;
static unsigned long old_pgdat_snr = NR_MEM_SECTIONS;
struct pglist_data *pgdat = NODE_DATA(nid);
int usemap_nid;
usemap_snr = pfn_to_section_nr(__pa(usemap) >> PAGE_SHIFT);
pgdat_snr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT);
if (usemap_snr == pgdat_snr)
return;
if (old_usemap_snr == usemap_snr && old_pgdat_snr == pgdat_snr)
/* skip redundant message */
return;
old_usemap_snr = usemap_snr;
old_pgdat_snr = pgdat_snr;
usemap_nid = sparse_early_nid(__nr_to_section(usemap_snr));
if (usemap_nid != nid) {
printk(KERN_INFO
"node %d must be removed before remove section %ld\n",
nid, usemap_snr);
return;
}
/*
* There is a circular dependency.
* Some platforms allow un-removable section because they will just
* gather other removable sections for dynamic partitioning.
* Just notify un-removable section's number here.
*/
printk(KERN_INFO "Section %ld and %ld (node %d)", usemap_snr,
pgdat_snr, nid);
printk(KERN_CONT
" have a circular dependency on usemap and pgdat allocations\n");
}
#else
static unsigned long * __init
sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
unsigned long size)
{
return alloc_bootmem_node_nopanic(pgdat, size);
}
static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
{
}
#endif /* CONFIG_MEMORY_HOTREMOVE */
static void __init sparse_early_usemaps_alloc_node(unsigned long**usemap_map,
unsigned long pnum_begin,
unsigned long pnum_end,
unsigned long usemap_count, int nodeid)
{
void *usemap;
unsigned long pnum;
int size = usemap_size();
usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nodeid),
size * usemap_count);
if (!usemap) {
printk(KERN_WARNING "%s: allocation failed\n", __func__);
return;
}
for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
if (!present_section_nr(pnum))
continue;
usemap_map[pnum] = usemap;
usemap += size;
check_usemap_section_nr(nodeid, usemap_map[pnum]);
}
}
#ifndef CONFIG_SPARSEMEM_VMEMMAP
struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid)
{
struct page *map;
unsigned long size;
map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
if (map)
return map;
size = PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
map = __alloc_bootmem_node_high(NODE_DATA(nid), size,
PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
return map;
}
void __init sparse_mem_maps_populate_node(struct page **map_map,
unsigned long pnum_begin,
unsigned long pnum_end,
unsigned long map_count, int nodeid)
{
void *map;
unsigned long pnum;
unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
map = alloc_remap(nodeid, size * map_count);
if (map) {
for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
if (!present_section_nr(pnum))
continue;
map_map[pnum] = map;
map += size;
}
return;
}
size = PAGE_ALIGN(size);
map = __alloc_bootmem_node_high(NODE_DATA(nodeid), size * map_count,
PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
if (map) {
for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
if (!present_section_nr(pnum))
continue;
map_map[pnum] = map;
map += size;
}
return;
}
/* fallback */
for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
struct mem_section *ms;
if (!present_section_nr(pnum))
continue;
map_map[pnum] = sparse_mem_map_populate(pnum, nodeid);
if (map_map[pnum])
continue;
ms = __nr_to_section(pnum);
printk(KERN_ERR "%s: sparsemem memory map backing failed "
"some memory will not be available.\n", __func__);
ms->section_mem_map = 0;
}
}
#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
static void __init sparse_early_mem_maps_alloc_node(struct page **map_map,
unsigned long pnum_begin,
unsigned long pnum_end,
unsigned long map_count, int nodeid)
{
sparse_mem_maps_populate_node(map_map, pnum_begin, pnum_end,
map_count, nodeid);
}
#else
static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
{
struct page *map;
struct mem_section *ms = __nr_to_section(pnum);
int nid = sparse_early_nid(ms);
map = sparse_mem_map_populate(pnum, nid);
if (map)
return map;
printk(KERN_ERR "%s: sparsemem memory map backing failed "
"some memory will not be available.\n", __func__);
ms->section_mem_map = 0;
return NULL;
}
#endif
void __attribute__((weak)) __meminit vmemmap_populate_print_last(void)
{
}
/*
* Allocate the accumulated non-linear sections, allocate a mem_map
* for each and record the physical to section mapping.
*/
void __init sparse_init(void)
{
unsigned long pnum;
struct page *map;
unsigned long *usemap;
unsigned long **usemap_map;
int size;
int nodeid_begin = 0;
unsigned long pnum_begin = 0;
unsigned long usemap_count;
#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
unsigned long map_count;
int size2;
struct page **map_map;
#endif
/*
* map is using big page (aka 2M in x86 64 bit)
* usemap is less one page (aka 24 bytes)
* so alloc 2M (with 2M align) and 24 bytes in turn will
* make next 2M slip to one more 2M later.
* then in big system, the memory will have a lot of holes...
* here try to allocate 2M pages continuously.
*
* powerpc need to call sparse_init_one_section right after each
* sparse_early_mem_map_alloc, so allocate usemap_map at first.
*/
size = sizeof(unsigned long *) * NR_MEM_SECTIONS;
usemap_map = alloc_bootmem(size);
if (!usemap_map)
panic("can not allocate usemap_map\n");
for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
struct mem_section *ms;
if (!present_section_nr(pnum))
continue;
ms = __nr_to_section(pnum);
nodeid_begin = sparse_early_nid(ms);
pnum_begin = pnum;
break;
}
usemap_count = 1;
for (pnum = pnum_begin + 1; pnum < NR_MEM_SECTIONS; pnum++) {
struct mem_section *ms;
int nodeid;
if (!present_section_nr(pnum))
continue;
ms = __nr_to_section(pnum);
nodeid = sparse_early_nid(ms);
if (nodeid == nodeid_begin) {
usemap_count++;
continue;
}
/* ok, we need to take cake of from pnum_begin to pnum - 1*/
sparse_early_usemaps_alloc_node(usemap_map, pnum_begin, pnum,
usemap_count, nodeid_begin);
/* new start, update count etc*/
nodeid_begin = nodeid;
pnum_begin = pnum;
usemap_count = 1;
}
/* ok, last chunk */
sparse_early_usemaps_alloc_node(usemap_map, pnum_begin, NR_MEM_SECTIONS,
usemap_count, nodeid_begin);
#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
size2 = sizeof(struct page *) * NR_MEM_SECTIONS;
map_map = alloc_bootmem(size2);
if (!map_map)
panic("can not allocate map_map\n");
for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
struct mem_section *ms;
if (!present_section_nr(pnum))
continue;
ms = __nr_to_section(pnum);
nodeid_begin = sparse_early_nid(ms);
pnum_begin = pnum;
break;
}
map_count = 1;
for (pnum = pnum_begin + 1; pnum < NR_MEM_SECTIONS; pnum++) {
struct mem_section *ms;
int nodeid;
if (!present_section_nr(pnum))
continue;
ms = __nr_to_section(pnum);
nodeid = sparse_early_nid(ms);
if (nodeid == nodeid_begin) {
map_count++;
continue;
}
/* ok, we need to take cake of from pnum_begin to pnum - 1*/
sparse_early_mem_maps_alloc_node(map_map, pnum_begin, pnum,
map_count, nodeid_begin);
/* new start, update count etc*/
nodeid_begin = nodeid;
pnum_begin = pnum;
map_count = 1;
}
/* ok, last chunk */
sparse_early_mem_maps_alloc_node(map_map, pnum_begin, NR_MEM_SECTIONS,
map_count, nodeid_begin);
#endif
for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
if (!present_section_nr(pnum))
continue;
usemap = usemap_map[pnum];
if (!usemap)
continue;
#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
map = map_map[pnum];
#else
map = sparse_early_mem_map_alloc(pnum);
#endif
if (!map)
continue;
sparse_init_one_section(__nr_to_section(pnum), pnum, map,
usemap);
}
vmemmap_populate_print_last();
#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
free_bootmem(__pa(map_map), size2);
#endif
free_bootmem(__pa(usemap_map), size);
}
#ifdef CONFIG_MEMORY_HOTPLUG
#ifdef CONFIG_SPARSEMEM_VMEMMAP
static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
unsigned long nr_pages)
{
/* This will make the necessary allocations eventually. */
return sparse_mem_map_populate(pnum, nid);
}
static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
{
return; /* XXX: Not implemented yet */
}
static void free_map_bootmem(struct page *page, unsigned long nr_pages)
{
}
#else
static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
{
struct page *page, *ret;
unsigned long memmap_size = sizeof(struct page) * nr_pages;
page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
if (page)
goto got_map_page;
ret = vmalloc(memmap_size);
if (ret)
goto got_map_ptr;
return NULL;
got_map_page:
ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
got_map_ptr:
memset(ret, 0, memmap_size);
return ret;
}
static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
unsigned long nr_pages)
{
return __kmalloc_section_memmap(nr_pages);
}
static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
{
if (is_vmalloc_addr(memmap))
vfree(memmap);
else
free_pages((unsigned long)memmap,
get_order(sizeof(struct page) * nr_pages));
}
static void free_map_bootmem(struct page *page, unsigned long nr_pages)
{
unsigned long maps_section_nr, removing_section_nr, i;
unsigned long magic;
for (i = 0; i < nr_pages; i++, page++) {
magic = (unsigned long) page->lru.next;
BUG_ON(magic == NODE_INFO);
maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
removing_section_nr = page->private;
/*
* When this function is called, the removing section is
* logical offlined state. This means all pages are isolated
* from page allocator. If removing section's memmap is placed
* on the same section, it must not be freed.
* If it is freed, page allocator may allocate it which will
* be removed physically soon.
*/
if (maps_section_nr != removing_section_nr)
put_page_bootmem(page);
}
}
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
static void free_section_usemap(struct page *memmap, unsigned long *usemap)
{
struct page *usemap_page;
unsigned long nr_pages;
if (!usemap)
return;
usemap_page = virt_to_page(usemap);
/*
* Check to see if allocation came from hot-plug-add
*/
if (PageSlab(usemap_page)) {
kfree(usemap);
if (memmap)
__kfree_section_memmap(memmap, PAGES_PER_SECTION);
return;
}
/*
* The usemap came from bootmem. This is packed with other usemaps
* on the section which has pgdat at boot time. Just keep it as is now.
*/
if (memmap) {
struct page *memmap_page;
memmap_page = virt_to_page(memmap);
nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
>> PAGE_SHIFT;
free_map_bootmem(memmap_page, nr_pages);
}
}
/*
* returns the number of sections whose mem_maps were properly
* set. If this is <=0, then that means that the passed-in
* map was not consumed and must be freed.
*/
int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
int nr_pages)
{
unsigned long section_nr = pfn_to_section_nr(start_pfn);
struct pglist_data *pgdat = zone->zone_pgdat;
struct mem_section *ms;
struct page *memmap;
unsigned long *usemap;
unsigned long flags;
int ret;
/*
* no locking for this, because it does its own
* plus, it does a kmalloc
*/
ret = sparse_index_init(section_nr, pgdat->node_id);
if (ret < 0 && ret != -EEXIST)
return ret;
memmap = kmalloc_section_memmap(section_nr, pgdat->node_id, nr_pages);
if (!memmap)
return -ENOMEM;
usemap = __kmalloc_section_usemap();
if (!usemap) {
__kfree_section_memmap(memmap, nr_pages);
return -ENOMEM;
}
pgdat_resize_lock(pgdat, &flags);
ms = __pfn_to_section(start_pfn);
if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
ret = -EEXIST;
goto out;
}
ms->section_mem_map |= SECTION_MARKED_PRESENT;
ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
out:
pgdat_resize_unlock(pgdat, &flags);
if (ret <= 0) {
kfree(usemap);
__kfree_section_memmap(memmap, nr_pages);
}
return ret;
}
void sparse_remove_one_section(struct zone *zone, struct mem_section *ms)
{
struct page *memmap = NULL;
unsigned long *usemap = NULL;
if (ms->section_mem_map) {
usemap = ms->pageblock_flags;
memmap = sparse_decode_mem_map(ms->section_mem_map,
__section_nr(ms));
ms->section_mem_map = 0;
ms->pageblock_flags = NULL;
}
free_section_usemap(memmap, usemap);
}
#endif