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-rw-r--r--mm/mmap.c129
1 files changed, 51 insertions, 78 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index 772140c53ab1..bbdc9af5e117 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -84,10 +84,14 @@ pgprot_t vm_get_page_prot(unsigned long vm_flags)
}
EXPORT_SYMBOL(vm_get_page_prot);
-int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */
-int sysctl_overcommit_ratio = 50; /* default is 50% */
+int sysctl_overcommit_memory __read_mostly = OVERCOMMIT_GUESS; /* heuristic overcommit */
+int sysctl_overcommit_ratio __read_mostly = 50; /* default is 50% */
int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;
-struct percpu_counter vm_committed_as;
+/*
+ * Make sure vm_committed_as in one cacheline and not cacheline shared with
+ * other variables. It can be updated by several CPUs frequently.
+ */
+struct percpu_counter vm_committed_as ____cacheline_aligned_in_smp;
/*
* Check that a process has enough memory to allocate a new virtual
@@ -190,7 +194,7 @@ error:
}
/*
- * Requires inode->i_mapping->i_mmap_lock
+ * Requires inode->i_mapping->i_mmap_mutex
*/
static void __remove_shared_vm_struct(struct vm_area_struct *vma,
struct file *file, struct address_space *mapping)
@@ -218,9 +222,9 @@ void unlink_file_vma(struct vm_area_struct *vma)
if (file) {
struct address_space *mapping = file->f_mapping;
- spin_lock(&mapping->i_mmap_lock);
+ mutex_lock(&mapping->i_mmap_mutex);
__remove_shared_vm_struct(vma, file, mapping);
- spin_unlock(&mapping->i_mmap_lock);
+ mutex_unlock(&mapping->i_mmap_mutex);
}
}
@@ -394,29 +398,6 @@ find_vma_prepare(struct mm_struct *mm, unsigned long addr,
return vma;
}
-static inline void
-__vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
- struct vm_area_struct *prev, struct rb_node *rb_parent)
-{
- struct vm_area_struct *next;
-
- vma->vm_prev = prev;
- if (prev) {
- next = prev->vm_next;
- prev->vm_next = vma;
- } else {
- mm->mmap = vma;
- if (rb_parent)
- next = rb_entry(rb_parent,
- struct vm_area_struct, vm_rb);
- else
- next = NULL;
- }
- vma->vm_next = next;
- if (next)
- next->vm_prev = vma;
-}
-
void __vma_link_rb(struct mm_struct *mm, struct vm_area_struct *vma,
struct rb_node **rb_link, struct rb_node *rb_parent)
{
@@ -464,16 +445,14 @@ static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
if (vma->vm_file)
mapping = vma->vm_file->f_mapping;
- if (mapping) {
- spin_lock(&mapping->i_mmap_lock);
- vma->vm_truncate_count = mapping->truncate_count;
- }
+ if (mapping)
+ mutex_lock(&mapping->i_mmap_mutex);
__vma_link(mm, vma, prev, rb_link, rb_parent);
__vma_link_file(vma);
if (mapping)
- spin_unlock(&mapping->i_mmap_lock);
+ mutex_unlock(&mapping->i_mmap_mutex);
mm->map_count++;
validate_mm(mm);
@@ -576,17 +555,8 @@ again: remove_next = 1 + (end > next->vm_end);
mapping = file->f_mapping;
if (!(vma->vm_flags & VM_NONLINEAR))
root = &mapping->i_mmap;
- spin_lock(&mapping->i_mmap_lock);
- if (importer &&
- vma->vm_truncate_count != next->vm_truncate_count) {
- /*
- * unmap_mapping_range might be in progress:
- * ensure that the expanding vma is rescanned.
- */
- importer->vm_truncate_count = 0;
- }
+ mutex_lock(&mapping->i_mmap_mutex);
if (insert) {
- insert->vm_truncate_count = vma->vm_truncate_count;
/*
* Put into prio_tree now, so instantiated pages
* are visible to arm/parisc __flush_dcache_page
@@ -605,7 +575,7 @@ again: remove_next = 1 + (end > next->vm_end);
* lock may be shared between many sibling processes. Skipping
* the lock for brk adjustments makes a difference sometimes.
*/
- if (vma->anon_vma && (insert || importer || start != vma->vm_start)) {
+ if (vma->anon_vma && (importer || start != vma->vm_start)) {
anon_vma = vma->anon_vma;
anon_vma_lock(anon_vma);
}
@@ -652,7 +622,7 @@ again: remove_next = 1 + (end > next->vm_end);
if (anon_vma)
anon_vma_unlock(anon_vma);
if (mapping)
- spin_unlock(&mapping->i_mmap_lock);
+ mutex_unlock(&mapping->i_mmap_mutex);
if (remove_next) {
if (file) {
@@ -699,9 +669,17 @@ static inline int is_mergeable_vma(struct vm_area_struct *vma,
}
static inline int is_mergeable_anon_vma(struct anon_vma *anon_vma1,
- struct anon_vma *anon_vma2)
+ struct anon_vma *anon_vma2,
+ struct vm_area_struct *vma)
{
- return !anon_vma1 || !anon_vma2 || (anon_vma1 == anon_vma2);
+ /*
+ * The list_is_singular() test is to avoid merging VMA cloned from
+ * parents. This can improve scalability caused by anon_vma lock.
+ */
+ if ((!anon_vma1 || !anon_vma2) && (!vma ||
+ list_is_singular(&vma->anon_vma_chain)))
+ return 1;
+ return anon_vma1 == anon_vma2;
}
/*
@@ -720,7 +698,7 @@ can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags,
struct anon_vma *anon_vma, struct file *file, pgoff_t vm_pgoff)
{
if (is_mergeable_vma(vma, file, vm_flags) &&
- is_mergeable_anon_vma(anon_vma, vma->anon_vma)) {
+ is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
if (vma->vm_pgoff == vm_pgoff)
return 1;
}
@@ -739,7 +717,7 @@ can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
struct anon_vma *anon_vma, struct file *file, pgoff_t vm_pgoff)
{
if (is_mergeable_vma(vma, file, vm_flags) &&
- is_mergeable_anon_vma(anon_vma, vma->anon_vma)) {
+ is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
pgoff_t vm_pglen;
vm_pglen = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
if (vma->vm_pgoff + vm_pglen == vm_pgoff)
@@ -817,7 +795,7 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
can_vma_merge_before(next, vm_flags,
anon_vma, file, pgoff+pglen) &&
is_mergeable_anon_vma(prev->anon_vma,
- next->anon_vma)) {
+ next->anon_vma, NULL)) {
/* cases 1, 6 */
err = vma_adjust(prev, prev->vm_start,
next->vm_end, prev->vm_pgoff, NULL);
@@ -982,7 +960,7 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
{
struct mm_struct * mm = current->mm;
struct inode *inode;
- unsigned int vm_flags;
+ vm_flags_t vm_flags;
int error;
unsigned long reqprot = prot;
@@ -1187,7 +1165,7 @@ SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg)
*/
int vma_wants_writenotify(struct vm_area_struct *vma)
{
- unsigned int vm_flags = vma->vm_flags;
+ vm_flags_t vm_flags = vma->vm_flags;
/* If it was private or non-writable, the write bit is already clear */
if ((vm_flags & (VM_WRITE|VM_SHARED)) != ((VM_WRITE|VM_SHARED)))
@@ -1215,7 +1193,7 @@ int vma_wants_writenotify(struct vm_area_struct *vma)
* We account for memory if it's a private writeable mapping,
* not hugepages and VM_NORESERVE wasn't set.
*/
-static inline int accountable_mapping(struct file *file, unsigned int vm_flags)
+static inline int accountable_mapping(struct file *file, vm_flags_t vm_flags)
{
/*
* hugetlb has its own accounting separate from the core VM
@@ -1229,7 +1207,7 @@ static inline int accountable_mapping(struct file *file, unsigned int vm_flags)
unsigned long mmap_region(struct file *file, unsigned long addr,
unsigned long len, unsigned long flags,
- unsigned int vm_flags, unsigned long pgoff)
+ vm_flags_t vm_flags, unsigned long pgoff)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma, *prev;
@@ -1785,7 +1763,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
/*
* vma is the first one with address < vma->vm_start. Have to extend vma.
*/
-static int expand_downwards(struct vm_area_struct *vma,
+int expand_downwards(struct vm_area_struct *vma,
unsigned long address)
{
int error;
@@ -1832,11 +1810,6 @@ static int expand_downwards(struct vm_area_struct *vma,
return error;
}
-int expand_stack_downwards(struct vm_area_struct *vma, unsigned long address)
-{
- return expand_downwards(vma, address);
-}
-
#ifdef CONFIG_STACK_GROWSUP
int expand_stack(struct vm_area_struct *vma, unsigned long address)
{
@@ -1919,17 +1892,17 @@ static void unmap_region(struct mm_struct *mm,
unsigned long start, unsigned long end)
{
struct vm_area_struct *next = prev? prev->vm_next: mm->mmap;
- struct mmu_gather *tlb;
+ struct mmu_gather tlb;
unsigned long nr_accounted = 0;
lru_add_drain();
- tlb = tlb_gather_mmu(mm, 0);
+ tlb_gather_mmu(&tlb, mm, 0);
update_hiwater_rss(mm);
unmap_vmas(&tlb, vma, start, end, &nr_accounted, NULL);
vm_unacct_memory(nr_accounted);
- free_pgtables(tlb, vma, prev? prev->vm_end: FIRST_USER_ADDRESS,
- next? next->vm_start: 0);
- tlb_finish_mmu(tlb, start, end);
+ free_pgtables(&tlb, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS,
+ next ? next->vm_start : 0);
+ tlb_finish_mmu(&tlb, start, end);
}
/*
@@ -2271,7 +2244,7 @@ EXPORT_SYMBOL(do_brk);
/* Release all mmaps. */
void exit_mmap(struct mm_struct *mm)
{
- struct mmu_gather *tlb;
+ struct mmu_gather tlb;
struct vm_area_struct *vma;
unsigned long nr_accounted = 0;
unsigned long end;
@@ -2296,14 +2269,14 @@ void exit_mmap(struct mm_struct *mm)
lru_add_drain();
flush_cache_mm(mm);
- tlb = tlb_gather_mmu(mm, 1);
+ tlb_gather_mmu(&tlb, mm, 1);
/* update_hiwater_rss(mm) here? but nobody should be looking */
/* Use -1 here to ensure all VMAs in the mm are unmapped */
end = unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, NULL);
vm_unacct_memory(nr_accounted);
- free_pgtables(tlb, vma, FIRST_USER_ADDRESS, 0);
- tlb_finish_mmu(tlb, 0, end);
+ free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, 0);
+ tlb_finish_mmu(&tlb, 0, end);
/*
* Walk the list again, actually closing and freeing it,
@@ -2317,7 +2290,7 @@ void exit_mmap(struct mm_struct *mm)
/* Insert vm structure into process list sorted by address
* and into the inode's i_mmap tree. If vm_file is non-NULL
- * then i_mmap_lock is taken here.
+ * then i_mmap_mutex is taken here.
*/
int insert_vm_struct(struct mm_struct * mm, struct vm_area_struct * vma)
{
@@ -2529,15 +2502,15 @@ static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma)
* The LSB of head.next can't change from under us
* because we hold the mm_all_locks_mutex.
*/
- spin_lock_nest_lock(&anon_vma->root->lock, &mm->mmap_sem);
+ mutex_lock_nest_lock(&anon_vma->root->mutex, &mm->mmap_sem);
/*
* We can safely modify head.next after taking the
- * anon_vma->root->lock. If some other vma in this mm shares
+ * anon_vma->root->mutex. If some other vma in this mm shares
* the same anon_vma we won't take it again.
*
* No need of atomic instructions here, head.next
* can't change from under us thanks to the
- * anon_vma->root->lock.
+ * anon_vma->root->mutex.
*/
if (__test_and_set_bit(0, (unsigned long *)
&anon_vma->root->head.next))
@@ -2559,7 +2532,7 @@ static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping)
*/
if (test_and_set_bit(AS_MM_ALL_LOCKS, &mapping->flags))
BUG();
- spin_lock_nest_lock(&mapping->i_mmap_lock, &mm->mmap_sem);
+ mutex_lock_nest_lock(&mapping->i_mmap_mutex, &mm->mmap_sem);
}
}
@@ -2586,7 +2559,7 @@ static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping)
* vma in this mm is backed by the same anon_vma or address_space.
*
* We can take all the locks in random order because the VM code
- * taking i_mmap_lock or anon_vma->lock outside the mmap_sem never
+ * taking i_mmap_mutex or anon_vma->mutex outside the mmap_sem never
* takes more than one of them in a row. Secondly we're protected
* against a concurrent mm_take_all_locks() by the mm_all_locks_mutex.
*
@@ -2642,7 +2615,7 @@ static void vm_unlock_anon_vma(struct anon_vma *anon_vma)
*
* No need of atomic instructions here, head.next
* can't change from under us until we release the
- * anon_vma->root->lock.
+ * anon_vma->root->mutex.
*/
if (!__test_and_clear_bit(0, (unsigned long *)
&anon_vma->root->head.next))
@@ -2658,7 +2631,7 @@ static void vm_unlock_mapping(struct address_space *mapping)
* AS_MM_ALL_LOCKS can't change to 0 from under us
* because we hold the mm_all_locks_mutex.
*/
- spin_unlock(&mapping->i_mmap_lock);
+ mutex_unlock(&mapping->i_mmap_mutex);
if (!test_and_clear_bit(AS_MM_ALL_LOCKS,
&mapping->flags))
BUG();