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-rw-r--r--mm/mmap.c64
1 files changed, 37 insertions, 27 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index 834b2d785f1e..20ff0c33274c 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -86,6 +86,7 @@ EXPORT_SYMBOL(vm_get_page_prot);
int sysctl_overcommit_memory __read_mostly = OVERCOMMIT_GUESS; /* heuristic overcommit */
int sysctl_overcommit_ratio __read_mostly = 50; /* default is 50% */
+unsigned long sysctl_overcommit_kbytes __read_mostly;
int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;
unsigned long sysctl_user_reserve_kbytes __read_mostly = 1UL << 17; /* 128MB */
unsigned long sysctl_admin_reserve_kbytes __read_mostly = 1UL << 13; /* 8MB */
@@ -893,7 +894,15 @@ again: remove_next = 1 + (end > next->vm_end);
static inline int is_mergeable_vma(struct vm_area_struct *vma,
struct file *file, unsigned long vm_flags)
{
- if (vma->vm_flags ^ vm_flags)
+ /*
+ * VM_SOFTDIRTY should not prevent from VMA merging, if we
+ * match the flags but dirty bit -- the caller should mark
+ * merged VMA as dirty. If dirty bit won't be excluded from
+ * comparison, we increase pressue on the memory system forcing
+ * the kernel to generate new VMAs when old one could be
+ * extended instead.
+ */
+ if ((vma->vm_flags ^ vm_flags) & ~VM_SOFTDIRTY)
return 0;
if (vma->vm_file != file)
return 0;
@@ -1082,7 +1091,7 @@ static int anon_vma_compatible(struct vm_area_struct *a, struct vm_area_struct *
return a->vm_end == b->vm_start &&
mpol_equal(vma_policy(a), vma_policy(b)) &&
a->vm_file == b->vm_file &&
- !((a->vm_flags ^ b->vm_flags) & ~(VM_READ|VM_WRITE|VM_EXEC)) &&
+ !((a->vm_flags ^ b->vm_flags) & ~(VM_READ|VM_WRITE|VM_EXEC|VM_SOFTDIRTY)) &&
b->vm_pgoff == a->vm_pgoff + ((b->vm_start - a->vm_start) >> PAGE_SHIFT);
}
@@ -1190,6 +1199,24 @@ static inline unsigned long round_hint_to_min(unsigned long hint)
return hint;
}
+static inline int mlock_future_check(struct mm_struct *mm,
+ unsigned long flags,
+ unsigned long len)
+{
+ unsigned long locked, lock_limit;
+
+ /* mlock MCL_FUTURE? */
+ if (flags & VM_LOCKED) {
+ locked = len >> PAGE_SHIFT;
+ locked += mm->locked_vm;
+ lock_limit = rlimit(RLIMIT_MEMLOCK);
+ lock_limit >>= PAGE_SHIFT;
+ if (locked > lock_limit && !capable(CAP_IPC_LOCK))
+ return -EAGAIN;
+ }
+ return 0;
+}
+
/*
* The caller must hold down_write(&current->mm->mmap_sem).
*/
@@ -1251,16 +1278,8 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
if (!can_do_mlock())
return -EPERM;
- /* mlock MCL_FUTURE? */
- if (vm_flags & VM_LOCKED) {
- unsigned long locked, lock_limit;
- locked = len >> PAGE_SHIFT;
- locked += mm->locked_vm;
- lock_limit = rlimit(RLIMIT_MEMLOCK);
- lock_limit >>= PAGE_SHIFT;
- if (locked > lock_limit && !capable(CAP_IPC_LOCK))
- return -EAGAIN;
- }
+ if (mlock_future_check(mm, vm_flags, len))
+ return -EAGAIN;
if (file) {
struct inode *inode = file_inode(file);
@@ -2591,18 +2610,9 @@ static unsigned long do_brk(unsigned long addr, unsigned long len)
if (error & ~PAGE_MASK)
return error;
- /*
- * mlock MCL_FUTURE?
- */
- if (mm->def_flags & VM_LOCKED) {
- unsigned long locked, lock_limit;
- locked = len >> PAGE_SHIFT;
- locked += mm->locked_vm;
- lock_limit = rlimit(RLIMIT_MEMLOCK);
- lock_limit >>= PAGE_SHIFT;
- if (locked > lock_limit && !capable(CAP_IPC_LOCK))
- return -EAGAIN;
- }
+ error = mlock_future_check(mm, mm->def_flags, len);
+ if (error)
+ return error;
/*
* mm->mmap_sem is required to protect against another thread
@@ -3140,7 +3150,7 @@ static int init_user_reserve(void)
sysctl_user_reserve_kbytes = min(free_kbytes / 32, 1UL << 17);
return 0;
}
-module_init(init_user_reserve)
+subsys_initcall(init_user_reserve);
/*
* Initialise sysctl_admin_reserve_kbytes.
@@ -3161,7 +3171,7 @@ static int init_admin_reserve(void)
sysctl_admin_reserve_kbytes = min(free_kbytes / 32, 1UL << 13);
return 0;
}
-module_init(init_admin_reserve)
+subsys_initcall(init_admin_reserve);
/*
* Reinititalise user and admin reserves if memory is added or removed.
@@ -3231,4 +3241,4 @@ static int __meminit init_reserve_notifier(void)
return 0;
}
-module_init(init_reserve_notifier)
+subsys_initcall(init_reserve_notifier);