[5/5] memrlimit correct mremap and move_vma accounting
- Date: Thu, 26 Jun 2008 14:59:18 +0530
- From: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
- Subject: [5/5] memrlimit correct mremap and move_vma accounting
The memrlimit patches did not account for move_vma() since we account for
address space usage in do_mremap(). The code flow actually increments
total_vm twice (once in do_mremap() and once in move_vma()), the excess
is removed in remove_vma_list() via do_munmap(). Since we did not do the
duplicate accounting, the code was seeing the extra uncharge, causing
our accounting to break. This patch fixes the problem
Signed-off-by: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
---
mm/mremap.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff -puN mm/mremap.c~memrlimit-fix-move-vma-accounting mm/mremap.c
--- linux-2.6.26-rc5/mm/mremap.c~memrlimit-fix-move-vma-accounting 2008-06-26 14:48:25.000000000 +0530
+++ linux-2.6.26-rc5-balbir/mm/mremap.c 2008-06-26 14:48:25.000000000 +0530
@@ -177,10 +177,15 @@ static unsigned long move_vma(struct vm_
if (mm->map_count >= sysctl_max_map_count - 3)
return -ENOMEM;
+ if (memrlimit_cgroup_charge_as(mm, new_len >> PAGE_SHIFT))
+ return -ENOMEM;
+
new_pgoff = vma->vm_pgoff + ((old_addr - vma->vm_start) >> PAGE_SHIFT);
new_vma = copy_vma(&vma, new_addr, new_len, new_pgoff);
- if (!new_vma)
+ if (!new_vma) {
+ memrlimit_cgroup_uncharge_as(mm, new_len >> PAGE_SHIFT);
return -ENOMEM;
+ }
moved_len = move_page_tables(vma, old_addr, new_vma, new_addr, old_len);
if (moved_len < old_len) {
@@ -386,6 +391,8 @@ unsigned long do_mremap(unsigned long ad
}
}
+ memrlimit_cgroup_uncharge_as(mm, (new_len - old_len) >> PAGE_SHIFT);
+
/*
* We weren't able to just expand or shrink the area,
* we need to create a new one and move it..
_
--
Warm Regards,
Balbir Singh
Linux Technology Center
IBM, ISTL
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/