[PATCH 5/9] mm: use mm_populate() when adjusting brk with MCL_FUTURE in effect.

From: Michel Lespinasse
Date: Thu Dec 20 2012 - 19:50:37 EST


Signed-off-by: Michel Lespinasse <walken@xxxxxxxxxx>

---
mm/mmap.c | 18 ++++++++++++++----
1 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index a16fc499dbd1..4c8d39e64e80 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -240,6 +240,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
unsigned long newbrk, oldbrk;
struct mm_struct *mm = current->mm;
unsigned long min_brk;
+ bool populate;

down_write(&mm->mmap_sem);

@@ -289,8 +290,15 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
/* Ok, looks good - let it rip. */
if (do_brk(oldbrk, newbrk-oldbrk) != oldbrk)
goto out;
+
set_brk:
mm->brk = brk;
+ populate = newbrk > oldbrk && (mm->def_flags & VM_LOCKED) != 0;
+ up_write(&mm->mmap_sem);
+ if (populate)
+ mm_populate(oldbrk, newbrk - oldbrk);
+ return brk;
+
out:
retval = mm->brk;
up_write(&mm->mmap_sem);
@@ -2274,10 +2282,8 @@ static unsigned long do_brk(unsigned long addr, unsigned long len)
out:
perf_event_mmap(vma);
mm->total_vm += len >> PAGE_SHIFT;
- if (flags & VM_LOCKED) {
- if (!mlock_vma_pages_range(vma, addr, addr + len))
- mm->locked_vm += (len >> PAGE_SHIFT);
- }
+ if (flags & VM_LOCKED)
+ mm->locked_vm += (len >> PAGE_SHIFT);
return addr;
}

@@ -2285,10 +2291,14 @@ unsigned long vm_brk(unsigned long addr, unsigned long len)
{
struct mm_struct *mm = current->mm;
unsigned long ret;
+ bool populate;

down_write(&mm->mmap_sem);
ret = do_brk(addr, len);
+ populate = ((mm->def_flags & VM_LOCKED) != 0);
up_write(&mm->mmap_sem);
+ if (populate)
+ mm_populate(addr, len);
return ret;
}
EXPORT_SYMBOL(vm_brk);
--
1.7.7.3
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