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authorLinus Torvalds <torvalds@linux-foundation.org>2010-10-26 10:13:10 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-26 10:13:10 -0700
commitf1ebdd60cc73ed36fd977f7e719ce70d2f5cd1c0 (patch)
tree225cb2ea2c0f8990f29383058a07206cfd835893
parentf99d055398d53c8f769d5153b3fdce1d2556e7ff (diff)
parent46e387bbd82d438b9131e237e6e2cb55a825da49 (diff)
Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6
* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (22 commits) Add _addr_lsb field to ia64 siginfo Fix migration.c compilation on s390 HWPOISON: Remove retry loop for try_to_unmap HWPOISON: Turn addr_valid from bitfield into char HWPOISON: Disable DEBUG by default HWPOISON: Convert pr_debugs to pr_info HWPOISON: Improve comments in memory-failure.c x86: HWPOISON: Report correct address granuality for huge hwpoison faults Encode huge page size for VM_FAULT_HWPOISON errors Fix build error with !CONFIG_MIGRATION hugepage: move is_hugepage_on_freelist inside ifdef to avoid warning Clean up __page_set_anon_rmap HWPOISON, hugetlb: fix unpoison for hugepage HWPOISON, hugetlb: soft offlining for hugepage HWPOSION, hugetlb: recover from free hugepage error when !MF_COUNT_INCREASED hugetlb: move refcounting in hugepage allocation inside hugetlb_lock HWPOISON, hugetlb: add free check to dequeue_hwpoison_huge_page() hugetlb: hugepage migration core hugetlb: redefine hugepage copy functions hugetlb: add allocate function for hugepage migration ...
-rw-r--r--arch/ia64/include/asm/siginfo.h1
-rw-r--r--arch/x86/mm/fault.c19
-rw-r--r--fs/hugetlbfs/inode.c15
-rw-r--r--fs/signalfd.c10
-rw-r--r--include/linux/hugetlb.h17
-rw-r--r--include/linux/migrate.h16
-rw-r--r--include/linux/mm.h12
-rw-r--r--include/linux/signalfd.h3
-rw-r--r--mm/hugetlb.c233
-rw-r--r--mm/memory-failure.c175
-rw-r--r--mm/memory.c3
-rw-r--r--mm/migrate.c234
-rw-r--r--mm/rmap.c25
13 files changed, 596 insertions, 167 deletions
diff --git a/arch/ia64/include/asm/siginfo.h b/arch/ia64/include/asm/siginfo.h
index 118d42979003..c8fcaa2ac48f 100644
--- a/arch/ia64/include/asm/siginfo.h
+++ b/arch/ia64/include/asm/siginfo.h
@@ -62,6 +62,7 @@ typedef struct siginfo {
int _imm; /* immediate value for "break" */
unsigned int _flags; /* see below */
unsigned long _isr; /* isr */
+ short _addr_lsb; /* lsb of faulting address */
} _sigfault;
/* SIGPOLL */
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 79b0b372d2d0..852b319edbdc 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -11,6 +11,7 @@
#include <linux/kprobes.h> /* __kprobes, ... */
#include <linux/mmiotrace.h> /* kmmio_handler, ... */
#include <linux/perf_event.h> /* perf_sw_event */
+#include <linux/hugetlb.h> /* hstate_index_to_shift */
#include <asm/traps.h> /* dotraplinkage, ... */
#include <asm/pgalloc.h> /* pgd_*(), ... */
@@ -160,15 +161,20 @@ is_prefetch(struct pt_regs *regs, unsigned long error_code, unsigned long addr)
static void
force_sig_info_fault(int si_signo, int si_code, unsigned long address,
- struct task_struct *tsk)
+ struct task_struct *tsk, int fault)
{
+ unsigned lsb = 0;
siginfo_t info;
info.si_signo = si_signo;
info.si_errno = 0;
info.si_code = si_code;
info.si_addr = (void __user *)address;
- info.si_addr_lsb = si_code == BUS_MCEERR_AR ? PAGE_SHIFT : 0;
+ if (fault & VM_FAULT_HWPOISON_LARGE)
+ lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));
+ if (fault & VM_FAULT_HWPOISON)
+ lsb = PAGE_SHIFT;
+ info.si_addr_lsb = lsb;
force_sig_info(si_signo, &info, tsk);
}
@@ -722,7 +728,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
tsk->thread.error_code = error_code | (address >= TASK_SIZE);
tsk->thread.trap_no = 14;
- force_sig_info_fault(SIGSEGV, si_code, address, tsk);
+ force_sig_info_fault(SIGSEGV, si_code, address, tsk, 0);
return;
}
@@ -807,14 +813,14 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
tsk->thread.trap_no = 14;
#ifdef CONFIG_MEMORY_FAILURE
- if (fault & VM_FAULT_HWPOISON) {
+ if (fault & (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) {
printk(KERN_ERR
"MCE: Killing %s:%d due to hardware memory corruption fault at %lx\n",
tsk->comm, tsk->pid, address);
code = BUS_MCEERR_AR;
}
#endif
- force_sig_info_fault(SIGBUS, code, address, tsk);
+ force_sig_info_fault(SIGBUS, code, address, tsk, fault);
}
static noinline void
@@ -824,7 +830,8 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code,
if (fault & VM_FAULT_OOM) {
out_of_memory(regs, error_code, address);
} else {
- if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON))
+ if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|
+ VM_FAULT_HWPOISON_LARGE))
do_sigbus(regs, error_code, address, fault);
else
BUG();
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 113eba3d3c38..a14328d270e8 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -31,6 +31,7 @@
#include <linux/statfs.h>
#include <linux/security.h>
#include <linux/magic.h>
+#include <linux/migrate.h>
#include <asm/uaccess.h>
@@ -573,6 +574,19 @@ static int hugetlbfs_set_page_dirty(struct page *page)
return 0;
}
+static int hugetlbfs_migrate_page(struct address_space *mapping,
+ struct page *newpage, struct page *page)
+{
+ int rc;
+
+ rc = migrate_huge_page_move_mapping(mapping, newpage, page);
+ if (rc)
+ return rc;
+ migrate_page_copy(newpage, page);
+
+ return 0;
+}
+
static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
@@ -659,6 +673,7 @@ static const struct address_space_operations hugetlbfs_aops = {
.write_begin = hugetlbfs_write_begin,
.write_end = hugetlbfs_write_end,
.set_page_dirty = hugetlbfs_set_page_dirty,
+ .migratepage = hugetlbfs_migrate_page,
};
diff --git a/fs/signalfd.c b/fs/signalfd.c
index 74047304b01a..492465b451dd 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c
@@ -99,6 +99,16 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
#ifdef __ARCH_SI_TRAPNO
err |= __put_user(kinfo->si_trapno, &uinfo->ssi_trapno);
#endif
+#ifdef BUS_MCEERR_AO
+ /*
+ * Other callers might not initialize the si_lsb field,
+ * so check explicitly for the right codes here.
+ */
+ if (kinfo->si_code == BUS_MCEERR_AR ||
+ kinfo->si_code == BUS_MCEERR_AO)
+ err |= __put_user((short) kinfo->si_addr_lsb,
+ &uinfo->ssi_addr_lsb);
+#endif
break;
case __SI_CHLD:
err |= __put_user(kinfo->si_pid, &uinfo->ssi_pid);
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index f479700df61b..943c76b3d4bb 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -43,7 +43,8 @@ int hugetlb_reserve_pages(struct inode *inode, long from, long to,
struct vm_area_struct *vma,
int acctflags);
void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed);
-void __isolate_hwpoisoned_huge_page(struct page *page);
+int dequeue_hwpoisoned_huge_page(struct page *page);
+void copy_huge_page(struct page *dst, struct page *src);
extern unsigned long hugepages_treat_as_movable;
extern const unsigned long hugetlb_zero, hugetlb_infinity;
@@ -101,7 +102,10 @@ static inline void hugetlb_report_meminfo(struct seq_file *m)
#define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) ({BUG(); 0; })
#define hugetlb_fault(mm, vma, addr, flags) ({ BUG(); 0; })
#define huge_pte_offset(mm, address) 0
-#define __isolate_hwpoisoned_huge_page(page) 0
+#define dequeue_hwpoisoned_huge_page(page) 0
+static inline void copy_huge_page(struct page *dst, struct page *src)
+{
+}
#define hugetlb_change_protection(vma, address, end, newprot)
@@ -228,6 +232,8 @@ struct huge_bootmem_page {
struct hstate *hstate;
};
+struct page *alloc_huge_page_node(struct hstate *h, int nid);
+
/* arch callback */
int __init alloc_bootmem_huge_page(struct hstate *h);
@@ -301,8 +307,14 @@ static inline struct hstate *page_hstate(struct page *page)
return size_to_hstate(PAGE_SIZE << compound_order(page));
}
+static inline unsigned hstate_index_to_shift(unsigned index)
+{
+ return hstates[index].order + PAGE_SHIFT;
+}
+
#else
struct hstate {};
+#define alloc_huge_page_node(h, nid) NULL
#define alloc_bootmem_huge_page(h) NULL
#define hstate_file(f) NULL
#define hstate_vma(v) NULL
@@ -317,6 +329,7 @@ static inline unsigned int pages_per_huge_page(struct hstate *h)
{
return 1;
}
+#define hstate_index_to_shift(index) 0
#endif
#endif /* _LINUX_HUGETLB_H */
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 7238231b8dd4..085527fb8261 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -14,6 +14,8 @@ extern int migrate_page(struct address_space *,
struct page *, struct page *);
extern int migrate_pages(struct list_head *l, new_page_t x,
unsigned long private, int offlining);
+extern int migrate_huge_pages(struct list_head *l, new_page_t x,
+ unsigned long private, int offlining);
extern int fail_migrate_page(struct address_space *,
struct page *, struct page *);
@@ -23,12 +25,17 @@ extern int migrate_prep_local(void);
extern int migrate_vmas(struct mm_struct *mm,
const nodemask_t *from, const nodemask_t *to,
unsigned long flags);
+extern void migrate_page_copy(struct page *newpage, struct page *page);
+extern int migrate_huge_page_move_mapping(struct address_space *mapping,
+ struct page *newpage, struct page *page);
#else
#define PAGE_MIGRATION 0
static inline void putback_lru_pages(struct list_head *l) {}
static inline int migrate_pages(struct list_head *l, new_page_t x,
unsigned long private, int offlining) { return -ENOSYS; }
+static inline int migrate_huge_pages(struct list_head *l, new_page_t x,
+ unsigned long private, int offlining) { return -ENOSYS; }
static inline int migrate_prep(void) { return -ENOSYS; }
static inline int migrate_prep_local(void) { return -ENOSYS; }
@@ -40,6 +47,15 @@ static inline int migrate_vmas(struct mm_struct *mm,
return -ENOSYS;
}
+static inline void migrate_page_copy(struct page *newpage,
+ struct page *page) {}
+
+static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
+ struct page *newpage, struct page *page)
+{
+ return -ENOSYS;
+}
+
/* Possible settings for the migrate_page() method in address_operations */
#define migrate_page NULL
#define fail_migrate_page NULL
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 7687228dd3b7..a4c66846fb8f 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -718,12 +718,20 @@ static inline int page_mapped(struct page *page)
#define VM_FAULT_SIGBUS 0x0002
#define VM_FAULT_MAJOR 0x0004
#define VM_FAULT_WRITE 0x0008 /* Special case for get_user_pages */
-#define VM_FAULT_HWPOISON 0x0010 /* Hit poisoned page */
+#define VM_FAULT_HWPOISON 0x0010 /* Hit poisoned small page */
+#define VM_FAULT_HWPOISON_LARGE 0x0020 /* Hit poisoned large page. Index encoded in upper bits */
#define VM_FAULT_NOPAGE 0x0100 /* ->fault installed the pte, not return page */
#define VM_FAULT_LOCKED 0x0200 /* ->fault locked the returned page */
-#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON)
+#define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */
+
+#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON | \
+ VM_FAULT_HWPOISON_LARGE)
+
+/* Encode hstate index for a hwpoisoned large page */
+#define VM_FAULT_SET_HINDEX(x) ((x) << 12)
+#define VM_FAULT_GET_HINDEX(x) (((x) >> 12) & 0xf)
/*
* Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
diff --git a/include/linux/signalfd.h b/include/linux/signalfd.h
index b363b916c909..3ff4961da9b5 100644
--- a/include/linux/signalfd.h
+++ b/include/linux/signalfd.h
@@ -33,6 +33,7 @@ struct signalfd_siginfo {
__u64 ssi_utime;
__u64 ssi_stime;
__u64 ssi_addr;
+ __u16 ssi_addr_lsb;
/*
* Pad strcture to 128 bytes. Remember to update the
@@ -43,7 +44,7 @@ struct signalfd_siginfo {
* comes out of a read(2) and we really don't want to have
* a compat on read(2).
*/
- __u8 __pad[48];
+ __u8 __pad[46];
};
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index c03273807182..96991ded82fe 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -423,14 +423,14 @@ static void clear_huge_page(struct page *page,
}
}
-static void copy_gigantic_page(struct page *dst, struct page *src,
+static void copy_user_gigantic_page(struct page *dst, struct page *src,
unsigned long addr, struct vm_area_struct *vma)
{
int i;
struct hstate *h = hstate_vma(vma);
struct page *dst_base = dst;
struct page *src_base = src;
- might_sleep();
+
for (i = 0; i < pages_per_huge_page(h); ) {
cond_resched();
copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma);
@@ -440,14 +440,15 @@ static void copy_gigantic_page(struct page *dst, struct page *src,
src = mem_map_next(src, src_base, i);
}
}
-static void copy_huge_page(struct page *dst, struct page *src,
+
+static void copy_user_huge_page(struct page *dst, struct page *src,
unsigned long addr, struct vm_area_struct *vma)
{
int i;
struct hstate *h = hstate_vma(vma);
if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) {
- copy_gigantic_page(dst, src, addr, vma);
+ copy_user_gigantic_page(dst, src, addr, vma);
return;
}
@@ -458,6 +459,40 @@ static void copy_huge_page(struct page *dst, struct page *src,
}
}
+static void copy_gigantic_page(struct page *dst, struct page *src)
+{
+ int i;
+ struct hstate *h = page_hstate(src);
+ struct page *dst_base = dst;
+ struct page *src_base = src;
+
+ for (i = 0; i < pages_per_huge_page(h); ) {
+ cond_resched();
+ copy_highpage(dst, src);
+
+ i++;
+ dst = mem_map_next(dst, dst_base, i);
+ src = mem_map_next(src, src_base, i);
+ }
+}
+
+void copy_huge_page(struct page *dst, struct page *src)
+{
+ int i;
+ struct hstate *h = page_hstate(src);
+
+ if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) {
+ copy_gigantic_page(dst, src);
+ return;
+ }
+
+ might_sleep();
+ for (i = 0; i < pages_per_huge_page(h); i++) {
+ cond_resched();
+ copy_highpage(dst + i, src + i);
+ }
+}
+
static void enqueue_huge_page(struct hstate *h, struct page *page)
{
int nid = page_to_nid(page);
@@ -466,11 +501,24 @@ static void enqueue_huge_page(struct hstate *h, struct page *page)
h->free_huge_pages_node[nid]++;
}
+static struct page *dequeue_huge_page_node(struct hstate *h, int nid)
+{
+ struct page *page;
+
+ if (list_empty(&h->hugepage_freelists[nid]))
+ return NULL;
+ page = list_entry(h->hugepage_freelists[nid].next, struct page, lru);
+ list_del(&page->lru);
+ set_page_refcounted(page);
+ h->free_huge_pages--;
+ h->free_huge_pages_node[nid]--;
+ return page;
+}
+
static struct page *dequeue_huge_page_vma(struct hstate *h,
struct vm_area_struct *vma,
unsigned long address, int avoid_reserve)
{
- int nid;
struct page *page = NULL;
struct mempolicy *mpol;
nodemask_t *nodemask;
@@ -496,19 +544,13 @@ static struct page *dequeue_huge_page_vma(struct hstate *h,
for_each_zone_zonelist_nodemask(zone, z, zonelist,
MAX_NR_ZONES - 1, nodemask) {
- nid = zone_to_nid(zone);
- if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) &&
- !list_empty(&h->hugepage_freelists[nid])) {
- page = list_entry(h->hugepage_freelists[nid].next,
- struct page, lru);
- list_del(&page->lru);
- h->free_huge_pages--;
- h->free_huge_pages_node[nid]--;
-
- if (!avoid_reserve)
- decrement_hugepage_resv_vma(h, vma);
-
- break;
+ if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask)) {
+ page = dequeue_huge_page_node(h, zone_to_nid(zone));
+ if (page) {
+ if (!avoid_reserve)
+ decrement_hugepage_resv_vma(h, vma);
+ break;
+ }
}
}
err:
@@ -770,11 +812,10 @@ static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed,
return ret;
}
-static struct page *alloc_buddy_huge_page(struct hstate *h,
- struct vm_area_struct *vma, unsigned long address)
+static struct page *alloc_buddy_huge_page(struct hstate *h, int nid)
{
struct page *page;
- unsigned int nid;
+ unsigned int r_nid;
if (h->order >= MAX_ORDER)
return NULL;
@@ -812,9 +853,14 @@ static struct page *alloc_buddy_huge_page(struct hstate *h,
}
spin_unlock(&hugetlb_lock);
- page = alloc_pages(htlb_alloc_mask|__GFP_COMP|
- __GFP_REPEAT|__GFP_NOWARN,
- huge_page_order(h));
+ if (nid == NUMA_NO_NODE)
+ page = alloc_pages(htlb_alloc_mask|__GFP_COMP|
+ __GFP_REPEAT|__GFP_NOWARN,
+ huge_page_order(h));
+ else
+ page = alloc_pages_exact_node(nid,
+ htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
+ __GFP_REPEAT|__GFP_NOWARN, huge_page_order(h));
if (page && arch_prepare_hugepage(page)) {
__free_pages(page, huge_page_order(h));
@@ -823,19 +869,13 @@ static struct page *alloc_buddy_huge_page(struct hstate *h,
spin_lock(&hugetlb_lock);
if (page) {
- /*
- * This page is now managed by the hugetlb allocator and has
- * no users -- drop the buddy allocator's reference.
- */
- put_page_testzero(page);
- VM_BUG_ON(page_count(page));
- nid = page_to_nid(page);
+ r_nid = page_to_nid(page);
set_compound_page_dtor(page, free_huge_page);
/*
* We incremented the global counters already
*/
- h->nr_huge_pages_node[nid]++;
- h->surplus_huge_pages_node[nid]++;
+ h->nr_huge_pages_node[r_nid]++;
+ h->surplus_huge_pages_node[r_nid]++;
__count_vm_event(HTLB_BUDDY_PGALLOC);
} else {
h->nr_huge_pages--;
@@ -848,6 +888,25 @@ static struct page *alloc_buddy_huge_page(struct hstate *h,
}
/*
+ * This allocation function is useful in the context where vma is irrelevant.
+ * E.g. soft-offlining uses this function because it only cares physical
+ * address of error page.
+ */
+struct page *alloc_huge_page_node(struct hstate *h, int nid)
+{
+ struct page *page;
+
+ spin_lock(&hugetlb_lock);
+ page = dequeue_huge_page_node(h, nid);
+ spin_unlock(&hugetlb_lock);
+
+ if (!page)
+ page = alloc_buddy_huge_page(h, nid);
+
+ return page;
+}
+
+/*
* Increase the hugetlb pool such that it can accomodate a reservation
* of size 'delta'.
*/
@@ -871,17 +930,14 @@ static int gather_surplus_pages(struct hstate *h, int delta)
retry:
spin_unlock(&hugetlb_lock);
for (i = 0; i < needed; i++) {
- page = alloc_buddy_huge_page(h, NULL, 0);
- if (!page) {
+ page = alloc_buddy_huge_page(h, NUMA_NO_NODE);
+ if (!page)
/*
* We were not able to allocate enough pages to
* satisfy the entire reservation so we free what
* we've allocated so far.
*/
- spin_lock(&hugetlb_lock);
- needed = 0;
goto free;
- }
list_add(&page->lru, &surplus_list);
}
@@ -908,31 +964,31 @@ retry:
needed += allocated;
h->resv_huge_pages += delta;
ret = 0;
-free:
+
+ spin_unlock(&hugetlb_lock);
/* Free the needed pages to the hugetlb pool */
list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
if ((--needed) < 0)
break;
list_del(&page->lru);
+ /*
+ * This page is now managed by the hugetlb allocator and has
+ * no users -- drop the buddy allocator's reference.
+ */
+ put_page_testzero(page);
+ VM_BUG_ON(page_count(page));
enqueue_huge_page(h, page);
}
/* Free unnecessary surplus pages to the buddy allocator */
+free:
if (!list_empty(&surplus_list)) {
- spin_unlock(&hugetlb_lock);
list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
list_del(&page->lru);
- /*
- * The page has a reference count of zero already, so
- * call free_huge_page directly instead of using
- * put_page. This must be done with hugetlb_lock
- * unlocked which is safe because free_huge_page takes
- * hugetlb_lock before deciding how to free the page.
- */
- free_huge_page(page);
+ put_page(page);
}
- spin_lock(&hugetlb_lock);
}
+ spin_lock(&hugetlb_lock);
return ret;
}
@@ -1052,14 +1108,13 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
spin_unlock(&hugetlb_lock);
if (!page) {
- page = alloc_buddy_huge_page(h, vma, addr);
+ page = alloc_buddy_huge_page(h, NUMA_NO_NODE);
if (!page) {
hugetlb_put_quota(inode->i_mapping, chg);
return ERR_PTR(-VM_FAULT_SIGBUS);
}
}
- set_page_refcounted(page);
set_page_private(page, (unsigned long) mapping);
vma_commit_reservation(h, vma, addr);
@@ -2153,6 +2208,19 @@ nomem:
return -ENOMEM;
}
+static int is_hugetlb_entry_migration(pte_t pte)
+{
+ swp_entry_t swp;
+
+ if (huge_pte_none(pte) || pte_present(pte))
+ return 0;
+ swp = pte_to_swp_entry(pte);
+ if (non_swap_entry(swp) && is_migration_entry(swp)) {
+ return 1;
+ } else
+ return 0;
+}
+
static int is_hugetlb_entry_hwpoisoned(pte_t pte)
{
swp_entry_t swp;
@@ -2383,7 +2451,7 @@ retry_avoidcopy:
if (unlikely(anon_vma_prepare(vma)))
return VM_FAULT_OOM;
- copy_huge_page(new_page, old_page, address, vma);
+ copy_user_huge_page(new_page, old_page, address, vma);
__SetPageUptodate(new_page);
/*
@@ -2515,22 +2583,20 @@ retry:
hugepage_add_new_anon_rmap(page, vma, address);
}
} else {
+ /*
+ * If memory error occurs between mmap() and fault, some process
+ * don't have hwpoisoned swap entry for errored virtual address.
+ * So we need to block hugepage fault by PG_hwpoison bit check.
+ */
+ if (unlikely(PageHWPoison(page))) {
+ ret = VM_FAULT_HWPOISON |
+ VM_FAULT_SET_HINDEX(h - hstates);
+ goto backout_unlocked;
+ }
page_dup_rmap(page);
}
/*
- * Since memory error handler replaces pte into hwpoison swap entry
- * at the time of error handling, a process which reserved but not have
- * the mapping to the error hugepage does not have hwpoison swap entry.
- * So we need to block accesses from such a process by checking
- * PG_hwpoison bit here.
- */
- if (unlikely(PageHWPoison(page))) {
- ret = VM_FAULT_HWPOISON;
- goto backout_unlocked;
- }
-
- /*
* If we are going to COW a private mapping later, we examine the
* pending reservations for this page now. This will ensure that
* any allocations necessary to record that reservation occur outside
@@ -2587,8 +2653,12 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
ptep = huge_pte_offset(mm, address);
if (ptep) {
entry = huge_ptep_get(ptep);
- if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
- return VM_FAULT_HWPOISON;
+ if (unlikely(is_hugetlb_entry_migration(entry))) {
+ migration_entry_wait(mm, (pmd_t *)ptep, address);
+ return 0;
+ } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
+ return VM_FAULT_HWPOISON_LARGE |
+ VM_FAULT_SET_HINDEX(h - hstates);
}
ptep = huge_pte_alloc(mm, address, huge_page_size(h));
@@ -2878,18 +2948,41 @@ void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)
hugetlb_acct_memory(h, -(chg - freed));
}
+#ifdef CONFIG_MEMORY_FAILURE
+
+/* Should be called in hugetlb_lock */
+static int is_hugepage_on_freelist(struct page *hpage)
+{
+ struct page *page;
+ struct page *tmp;
+ struct hstate *h = page_hstate(hpage);
+ int nid = page_to_nid(hpage);
+
+ list_for_each_entry_safe(page, tmp, &h->hugepage_freelists[nid], lru)
+ if (page == hpage)
+ return 1;
+ return 0;
+}
+
/*
* This function is called from memory failure code.
* Assume the caller holds page lock of the head page.
*/
-void __isolate_hwpoisoned_huge_page(struct page *hpage)
+int dequeue_hwpoisoned_huge_page(struct page *hpage)
{
struct hstate *h = page_hstate(hpage);
int nid = page_to_nid(hpage);
+ int ret = -EBUSY;
spin_lock(&hugetlb_lock);
- list_del(&hpage->lru);
- h->free_huge_pages--;
- h->free_huge_pages_node[nid]--;
+ if (is_hugepage_on_freelist(hpage)) {
+ list_del(&hpage->lru);
+ set_page_refcounted(hpage);
+ h->free_huge_pages--;
+ h->free_huge_pages_node[nid]--;
+ ret = 0;
+ }
spin_unlock(&hugetlb_lock);
+ return ret;
}
+#endif
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 757f6b0accfe..44a8cefeae6e 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -7,21 +7,26 @@
* Free Software Foundation.
*
* High level machine check handler. Handles pages reported by the
- * hardware as being corrupted usually due to a 2bit ECC memory or cache
+ * hardware as being corrupted usually due to a multi-bit ECC memory or cache
* failure.
+ *
+ * In addition there is a "soft offline" entry point that allows stop using
+ * not-yet-corrupted-by-suspicious pages without killing anything.
*
* Handles page cache pages in various states. The tricky part
- * here is that we can access any page asynchronous to other VM
- * users, because memory failures could happen anytime and anywhere,
- * possibly violating some of their assumptions. This is why this code
- * has to be extremely careful. Generally it tries to use normal locking
- * rules, as in get the standard locks, even if that means the
- * error handling takes potentially a long time.
- *
- * The operation to map back from RMAP chains to processes has to walk
- * the complete process list and has non linear complexity with the number
- * mappings. In short it can be quite slow. But since memory corruptions
- * are rare we hope to get away with this.
+ * here is that we can access any page asynchronously in respect to
+ * other VM users, because memory failures could happen anytime and
+ * anywhere. This could violate some of their assumptions. This is why
+ * this code has to be extremely careful. Generally it tries to use
+ * normal locking rules, as in get the standard locks, even if that means
+ * the error handling takes potentially a long time.
+ *
+ * There are several operations here with exponential complexity because
+ * of unsuitable VM data structures. For example the operation to map back
+ * from RMAP chains to processes has to walk the complete process list and
+ * has non linear complexity with the number. But since memory corruptions
+ * are rare we hope to get away with this. This avoids impacting the core
+ * VM.
*/
/*
@@ -30,7 +35,6 @@
* - kcore/oldmem/vmcore/mem/kmem check for hwpoison pages
* - pass bad pages to kdump next kernel
*/
-#define DEBUG 1 /* remove me in 2.6.34 */
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/page-flags.h>
@@ -78,7 +82,7 @@ static int hwpoison_filter_dev(struct page *p)
return 0;
/*
- * page_mapping() does not accept slab page
+ * page_mapping() does not accept slab pages.
*/
if (PageSlab(p))
return -EINVAL;
@@ -268,7 +272,7 @@ struct to_kill {
struct list_head nd;
struct task_struct *tsk;
unsigned long addr;
- unsigned addr_valid:1;
+ char addr_valid;
};
/*
@@ -309,7 +313,7 @@ static void add_to_kill(struct task_struct *tsk, struct page *p,
* a SIGKILL because the error is not contained anymore.
*/
if (tk->addr == -EFAULT) {
- pr_debug("MCE: Unable to find user space address %lx in %s\n",
+ pr_info("MCE: Unable to find user space address %lx in %s\n",
page_to_pfn(p), tsk->comm);
tk->addr_valid = 0;
}
@@ -577,7 +581,7 @@ static int me_pagecache_clean(struct page *p, unsigned long pfn)
pfn, err);
} else if (page_has_private(p) &&
!try_to_release_page(p, GFP_NOIO)) {
- pr_debug("MCE %#lx: failed to release buffers\n", pfn);
+ pr_info("MCE %#lx: failed to release buffers\n", pfn);
} else {
ret = RECOVERED;
}
@@ -693,11 +697,10 @@ static int me_swapcache_clean(struct page *p, unsigned long pfn)
* Issues:
* - Error on hugepage is contained in hugepage unit (not in raw page unit.)
* To narrow down kill region to one page, we need to break up pmd.
- * - To support soft-offlining for hugepage, we need to support hugepage
- * migration.
*/
static int me_huge_page(struct page *p, unsigned long pfn)
{
+ int res = 0;
struct page *hpage = compound_head(p);
/*
* We can safely recover from error on free or reserved (i.e.
@@ -710,8 +713,9 @@ static int me_huge_page(struct page *p, unsigned long pfn)
* so there is no race between isolation and mapping/unmapping.
*/
if (!(page_mapping(hpage) || PageAnon(hpage))) {
- __isolate_hwpoisoned_huge_page(hpage);
- return RECOVERED;
+ res = dequeue_hwpoisoned_huge_page(hpage);
+ if (!res)
+ return RECOVERED;
}
return DELAYED;
}
@@ -836,8 +840,6 @@ static int page_action(struct page_state *ps, struct page *p,
return (result == RECOVERED || result == DELAYED) ? 0 : -EBUSY;
}
-#define N_UNMAP_TRIES 5
-
/*
* Do all that is necessary to remove user space mappings. Unmap
* the pages and send SIGBUS to the processes if the data was dirty.
@@ -849,7 +851,6 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
struct address_space *mapping;
LIST_HEAD(tokill);
int ret;
- int i;
int kill = 1;
struct page *hpage = compound_head(p);
@@ -903,17 +904,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
if (kill)
collect_procs(hpage, &tokill);
- /*
- * try_to_unmap can fail temporarily due to races.
- * Try a few times (RED-PEN better strategy?)
- */
- for (i = 0; i < N_UNMAP_TRIES; i++) {
- ret = try_to_unmap(hpage, ttu);
- if (ret == SWAP_SUCCESS)
- break;
- pr_debug("MCE %#lx: try_to_unmap retry needed %d\n", pfn, ret);
- }
-
+ ret = try_to_unmap(hpage, ttu);
if (ret != SWAP_SUCCESS)
printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d)\n",
pfn, page_mapcount(hpage));
@@ -981,7 +972,10 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
* We need/can do nothing about count=0 pages.
* 1) it's a free page, and therefore in safe hand:
* prep_new_page() will be the gate keeper.
- * 2) it's part of a non-compound high order page.
+ * 2) it's a free hugepage, which is also safe:
+ * an affected hugepage will be dequeued from hugepage freelist,
+ * so there's no concern about reusing it ever after.
+ * 3) it's part of a non-compound high order page.
* Implies some kernel user: cannot stop them from
* R/W the page; let's pray that the page has been
* used and will be freed some time later.
@@ -993,6 +987,24 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
if (is_free_buddy_page(p)) {
action_result(pfn, "free buddy", DELAYED);
return 0;
+ } else if (PageHuge(hpage)) {
+ /*
+ * Check "just unpoisoned", "filter hit", and
+ * "race with other subpage."
+ */
+ lock_page_nosync(hpage);
+ if (!PageHWPoison(hpage)
+ || (hwpoison_filter(p) && TestClearPageHWPoison(p))
+ || (p != hpage && TestSetPageHWPoison(hpage))) {
+ atomic_long_sub(nr_pages, &mce_bad_pages);
+ return 0;
+ }
+ set_page_hwpoison_huge_page(hpage);
+ res = dequeue_hwpoisoned_huge_page(hpage);
+ action_result(pfn, "free huge",
+ res ? IGNORED : DELAYED);
+ unlock_page(hpage);
+ return res;
} else {
action_result(pfn, "high order kernel", IGNORED);
return -EBUSY;
@@ -1147,16 +1159,26 @@ int unpoison_memory(unsigned long pfn)
page = compound_head(p);
if (!PageHWPoison(p)) {
- pr_debug("MCE: Page was already unpoisoned %#lx\n", pfn);
+ pr_info("MCE: Page was already unpoisoned %#lx\n", pfn);
return 0;
}
nr_pages = 1 << compound_order(page);
if (!get_page_unless_zero(page)) {
+ /*
+ * Since HWPoisoned hugepage should have non-zero refcount,
+ * race between memory failure and unpoison seems to happen.
+ * In such case unpoison fails and memory failure runs
+ * to the end.
+ */
+ if (PageHuge(page)) {
+ pr_debug("MCE: Memory failure is now running on free hugepage %#lx\n", pfn);
+ return 0;
+ }
if (TestClearPageHWPoison(p))
atomic_long_sub(nr_pages, &mce_bad_pages);
- pr_debug("MCE: Software-unpoisoned free page %#lx\n", pfn);
+ pr_info("MCE: Software-unpoisoned free page %#lx\n", pfn);
return 0;
}
@@ -1168,12 +1190,12 @@ int unpoison_memory(unsigned long pfn)
* the free buddy page pool.
*/
if (TestClearPageHWPoison(page)) {
- pr_debug("MCE: Software-unpoisoned page %#lx\n", pfn);
+ pr_info("MCE: Software-unpoisoned page %#lx\n", pfn);
atomic_long_sub(nr_pages, &mce_bad_pages);
freeit = 1;
+ if (PageHuge(page))
+ clear_page_hwpoison_huge_page(page);
}
- if (PageHuge(p))
- clear_page_hwpoison_huge_page(page);
unlock_page(page);
put_page(page);
@@ -1187,7 +1209,11 @@ EXPORT_SYMBOL(unpoison_memory);
static struct page *new_page(struct page *p, unsigned long private, int **x)
{
int nid = page_to_nid(p);
- return alloc_pages_exact_node(nid, GFP_HIGHUSER_MOVABLE, 0);
+ if (PageHuge(p))
+ return alloc_huge_page_node(page_hstate(compound_head(p)),
+ nid);
+ else
+ return alloc_pages_exact_node(nid, GFP_HIGHUSER_MOVABLE, 0);
}
/*
@@ -1215,14 +1241,21 @@ static int get_any_page(struct page *p, unsigned long pfn, int flags)
* was free.
*/
set_migratetype_isolate(p);
+ /*
+ * When the target page is a free hugepage, just remove it
+ * from free hugepage list.
+ */
if (!get_page_unless_zero(compound_head(p))) {
- if (is_free_buddy_page(p)) {
- pr_debug("get_any_page: %#lx free buddy page\n", pfn);
+ if (PageHuge(p)) {
+ pr_info("get_any_page: %#lx free huge page\n", pfn);
+ ret = dequeue_hwpoisoned_huge_page(compound_head(p));
+ } else if (is_free_buddy_page(p)) {
+ pr_info("get_any_page: %#lx free buddy page\n", pfn);
/* Set hwpoison bit while page is still isolated */
SetPageHWPoison(p);
ret = 0;
} else {
- pr_debug("get_any_page: %#lx: unknown zero refcount page type %lx\n",
+ pr_info("get_any_page: %#lx: unknown zero refcount page type %lx\n",
pfn, p->flags);
ret = -EIO;
}
@@ -1235,6 +1268,45 @@ static int get_any_page(struct page *p, unsigned long pfn, int flags)
return ret;
}
+static int soft_offline_huge_page(struct page *page, int flags)
+{
+ int ret;
+ unsigned long pfn = page_to_pfn(page);
+ struct page *hpage = compound_head(page);
+ LIST_HEAD(pagelist);
+
+ ret = get_any_page(page, pfn, flags);
+ if (ret < 0)
+ return ret;
+ if (ret == 0)
+ goto done;
+
+ if (PageHWPoison(hpage)) {
+ put_page(hpage);
+ pr_debug("soft offline: %#lx hugepage already poisoned\n", pfn);
+ return -EBUSY;
+ }
+
+ /* Keep page count to indicate a given hugepage is isolated. */
+
+ list_add(&hpage->lru, &pagelist);
+ ret = migrate_huge_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0);
+ if (ret) {
+ pr_debug("soft offline: %#lx: migration failed %d, type %lx\n",
+ pfn, ret, page->flags);
+ if (ret > 0)
+ ret = -EIO;
+ return ret;
+ }
+done:
+ if (!PageHWPoison(hpage))
+ atomic_long_add(1 << compound_order(hpage), &mce_bad_pages);
+ set_page_hwpoison_huge_page(hpage);
+ dequeue_hwpoisoned_huge_page(hpage);
+ /* keep elevated page count for bad page */
+ return ret;
+}
+
/**
* soft_offline_page - Soft offline a page.
* @page: page to offline
@@ -1262,6 +1334,9 @@ int soft_offline_page(struct page *page, int flags)
int ret;
unsigned long pfn = page_to_pfn(page);
+ if (PageHuge(page))
+ return soft_offline_huge_page(page, flags);
+
ret = get_any_page(page, pfn, flags);
if (ret < 0)
return ret;
@@ -1288,7 +1363,7 @@ int soft_offline_page(struct page *page, int flags)
goto done;
}
if (!PageLRU(page)) {
- pr_debug("soft_offline: %#lx: unknown non LRU page type %lx\n",
+ pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n",
pfn, page->flags);
return -EIO;
}
@@ -1302,7 +1377,7 @@ int soft_offline_page(struct page *page, int flags)
if (PageHWPoison(page)) {
unlock_page(page);
put_page(page);
- pr_debug("soft offline: %#lx page already poisoned\n", pfn);
+ pr_info("soft offline: %#lx page already poisoned\n", pfn);
return -EBUSY;
}
@@ -1323,7 +1398,7 @@ int soft_offline_page(struct page *page, int flags)
put_page(page);
if (ret == 1) {
ret = 0;
- pr_debug("soft_offline: %#lx: invalidated\n", pfn);
+ pr_info("soft_offline: %#lx: invalidated\n", pfn);
goto done;
}
@@ -1339,13 +1414,13 @@ int soft_offline_page(struct page *page, int flags)
list_add(&page->lru, &pagelist);
ret = migrate_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0);
if (ret) {
- pr_debug("soft offline: %#lx: migration failed %d, type %lx\n",
+ pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
pfn, ret, page->flags);
if (ret > 0)
ret = -EIO;
}
} else {
- pr_debug("soft offline: %#lx: isolation failed: %d, page count %d, type %lx\n",
+ pr_info("soft offline: %#lx: isolation failed: %d, page count %d, type %lx\n",
pfn, ret, page_count(page), page->flags);
}
if (ret)
diff --git a/mm/memory.c b/mm/memory.c
index 98b58fecedef..af82741caaa4 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1450,7 +1450,8 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
if (ret & VM_FAULT_OOM)
return i ? i : -ENOMEM;
if (ret &
- (VM_FAULT_HWPOISON|VM_FAULT_SIGBUS))
+ (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE|
+ VM_FAULT_SIGBUS))
return i ? i : -EFAULT;
BUG();
}
diff --git a/mm/migrate.c b/mm/migrate.c
index 38e7cad782f4..f8c9bccf2520 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -32,6 +32,7 @@
#include <linux/security.h>
#include <linux/memcontrol.h>
#include <linux/syscalls.h>
+#include <linux/hugetlb.h>
#include <linux/gfp.h>
#include "internal.h"
@@ -95,26 +96,34 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
pte_t *ptep, pte;
spinlock_t *ptl;
- pgd = pgd_offset(mm, addr);
- if (!pgd_present(*pgd))
- goto out;
+ if (unlikely(PageHuge(new))) {
+ ptep = huge_pte_offset(mm, addr);
+ if (!ptep)
+ goto out;
+ ptl = &mm->page_table_lock;
+ } else {
+ pgd = pgd_offset(mm, addr);
+ if (!pgd_present(*pgd))
+ goto out;
- pud = pud_offset(pgd, addr);
- if (!pud_present(*pud))
- goto out;
+ pud = pud_offset(pgd, addr);
+ if (!pud_present(*pud))
+ goto out;
- pmd = pmd_offset(pud, addr);
- if (!pmd_present(*pmd))
- goto out;
+ pmd = pmd_offset(pud, addr);
+ if (!pmd_present(*pmd))
+ goto out;
- ptep = pte_offset_map(pmd, addr);
+ ptep = pte_offset_map(pmd, addr);
- if (!is_swap_pte(*ptep)) {
- pte_unmap(ptep);
- goto out;
- }
+ if (!is_swap_pte(*ptep)) {
+ pte_unmap(ptep);
+ goto out;
+ }
+
+ ptl = pte_lockptr(mm, pmd);
+ }
- ptl = pte_lockptr(mm, pmd);
spin_lock(ptl);
pte = *ptep;
if (!is_swap_pte(pte))
@@ -130,10 +139,19 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
pte = pte_mkold(mk_pte(new, vma->vm_page_prot));
if (is_write_migration_entry(entry))
pte = pte_mkwrite(pte);
+#ifdef CONFIG_HUGETLB_PAGE
+ if (PageHuge(new))
+ pte = pte_mkhuge(pte);
+#endif
flush_cache_page(vma, addr, pte_pfn(pte));
set_pte_at(mm, addr, ptep, pte);
- if (PageAnon(new))
+ if (PageHuge(new)) {
+ if (PageAnon(new))
+ hugepage_add_anon_rmap(new, vma, addr);
+ else
+ page_dup_rmap(new);
+ } else if (PageAnon(new))
page_add_anon_rmap(new, vma, addr);
else
page_add_file_rmap(new);
@@ -276,11 +294,59 @@ static int migrate_page_move_mapping(struct address_space *mapping,
}
/*
+ * The expected number of remaining references is the same as that
+ * of migrate_page_move_mapping().
+ */
+int migrate_huge_page_move_mapping(struct address_space *mapping,
+ struct page *newpage, struct page *page)
+{
+ int expected_count;
+ void **pslot;
+
+ if (!mapping) {
+ if (page_count(page) != 1)
+ return -EAGAIN;
+ return 0;
+ }
+
+ spin_lock_irq(&mapping->tree_lock);
+
+ pslot = radix_tree_lookup_slot(&mapping->page_tree,
+ page_index(page));
+
+ expected_count = 2 + page_has_private(page);
+ if (page_count(page) != expected_count ||
+ (struct page *)radix_tree_deref_slot(pslot) != page) {
+ spin_unlock_irq(&mapping->tree_lock);
+ return -EAGAIN;
+ }
+
+ if (!page_freeze_refs(page, expected_count)) {
+ spin_unlock_irq(&mapping->tree_lock);
+ return -EAGAIN;
+ }
+
+ get_page(newpage);
+
+ radix_tree_replace_slot(pslot, newpage);
+
+ page_unfreeze_refs(page, expected_count);
+
+ __put_page(page);
+
+ spin_unlock_irq(&mapping->tree_lock);
+ return 0;
+}
+
+/*
* Copy the page to its new location
*/
-static void migrate_page_copy(struct page *newpage, struct page *page)
+void migrate_page_copy(struct page *newpage, struct page *page)
{
- copy_highpage(newpage, page);
+ if (PageHuge(page))
+ copy_huge_page(newpage, page);
+ else
+ copy_highpage(newpage, page);
if (PageError(page))
SetPageError(newpage);
@@ -724,6 +790,92 @@ move_newpage:
}
/*
+ * Counterpart of unmap_and_move_page() for hugepage migration.
+ *
+ * This function doesn't wait the completion of hugepage I/O
+ * because there is no race between I/O and migration for hugepage.
+ * Note that currently hugepage I/O occurs only in direct I/O
+ * where no lock is held and PG_writeback is irrelevant,
+ * and writeback status of all subpages are counted in the reference
+ * count of the head page (i.e. if all subpages of a 2MB hugepage are
+ * under direct I/O, the reference of the head page is 512 and a bit more.)
+ * This means that when we try to migrate hugepage whose subpages are
+ * doing direct I/O, some references remain after try_to_unmap() and
+ * hugepage migration fails without data corruption.
+ *
+ * There is also no race when direct I/O is issued on the page under migration,
+ * because then pte is replaced with migration swap entry and direct I/O code
+ * will wait in the page fault for migration to complete.
+ */
+static int unmap_and_move_huge_page(new_page_t get_new_page,
+ unsigned long private, struct page *hpage,
+ int force, int offlining)
+{
+ int rc = 0;
+ int *result = NULL;
+ struct page *new_hpage = get_new_page(hpage, private, &result);
+ int rcu_locked = 0;
+ struct anon_vma *anon_vma = NULL;
+
+ if (!new_hpage)
+ return -ENOMEM;
+
+ rc = -EAGAIN;
+
+ if (!trylock_page(hpage)) {
+ if (!force)
+ goto out;
+ lock_page(hpage);
+ }
+
+ if (PageAnon(hpage)) {
+ rcu_read_lock();
+ rcu_locked = 1;
+
+ if (page_mapped(hpage)) {
+ anon_vma = page_anon_vma(hpage);
+ atomic_inc(&anon_vma->external_refcount);
+ }
+ }
+
+ try_to_unmap(hpage, TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS);
+
+ if (!page_mapped(hpage))
+ rc = move_to_new_page(new_hpage, hpage, 1);
+
+ if (rc)
+ remove_migration_ptes(hpage, hpage);
+
+ if (anon_vma && atomic_dec_and_lock(&anon_vma->external_refcount,
+ &anon_vma->lock)) {
+ int empty = list_empty(&anon_vma->head);
+ spin_unlock(&anon_vma->lock);
+ if (empty)
+ anon_vma_free(anon_vma);
+ }
+
+ if (rcu_locked)
+ rcu_read_unlock();
+out:
+ unlock_page(hpage);
+
+ if (rc != -EAGAIN) {
+ list_del(&hpage->lru);
+ put_page(hpage);
+ }
+
+ put_page(new_hpage);
+
+ if (result) {
+ if (rc)
+ *result = rc;
+ else
+ *result = page_to_nid(new_hpage);
+ }
+ return rc;
+}
+
+/*
* migrate_pages
*
* The function takes one list of pages to migrate and a function
@@ -788,6 +940,52 @@ out:
return nr_failed + retry;
}
+int migrate_huge_pages(struct list_head *from,
+ new_page_t get_new_page, unsigned long private, int offlining)
+{
+ int retry = 1;
+ int nr_failed = 0;
+ int pass = 0;
+ struct page *page;
+ struct page *page2;
+ int rc;
+
+ for (pass = 0; pass < 10 && retry; pass++) {
+ retry = 0;
+
+ list_for_each_entry_safe(page, page2, from, lru) {
+ cond_resched();
+
+ rc = unmap_and_move_huge_page(get_new_page,
+ private, page, pass > 2, offlining);
+
+ switch(rc) {
+ case -ENOMEM:
+ goto out;
+ case -EAGAIN:
+ retry++;
+ break;
+ case 0:
+ break;
+ default:
+ /* Permanent failure */
+ nr_failed++;
+ break;
+ }
+ }
+ }
+ rc = 0;
+out:
+
+ list_for_each_entry_safe(page, page2, from, lru)
+ put_page(page);
+
+ if (rc)
+ return rc;
+
+ return nr_failed + retry;
+}
+
#ifdef CONFIG_NUMA
/*
* Move a list of individual pages
diff --git a/mm/rmap.c b/mm/rmap.c
index 5f17fad1bee8..f5ad996a4a8f 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -780,10 +780,10 @@ void page_move_anon_rmap(struct page *page,
}
/**
- * __page_set_anon_rmap - setup new anonymous rmap
- * @page: the page to add the mapping to
- * @vma: the vm area in which the mapping is added
- * @address: the user virtual address mapped
+ * __page_set_anon_rmap - set up new anonymous rmap
+ * @page: Page to add to rmap
+ * @vma: VM area to add page to.
+ * @address: User virtual address of the mapping
* @exclusive: the page is exclusively owned by the current process
*/
static void __page_set_anon_rmap(struct page *page,
@@ -793,25 +793,16 @@ static void __page_set_anon_rmap(struct page *page,
BUG_ON(!anon_vma);
+ if (PageAnon(page))
+ return;
+
/*
* If the page isn't exclusively mapped into this vma,
* we must use the _oldest_ possible anon_vma for the
* page mapping!
*/
- if (!exclusive) {
- if (PageAnon(page))
- return;
+ if (!exclusive)
anon_vma = anon_vma->root;
- } else {
- /*
- * In this case, swapped-out-but-not-discarded swap-cache
- * is remapped. So, no need to update page->mapping here.
- * We convice anon_vma poitned by page->mapping is not obsolete
- * because vma->anon_vma is necessary to be a family of it.
- */
- if (PageAnon(page))
- return;
- }
anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
page->mapping = (struct address_space *) anon_vma;

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