oom: move oom_killer_enable()/oom_killer_disable to where they belong

[deliverable/linux.git] / mm / mremap.c

diff --git a/mm/mremap.c b/mm/mremap.c
index a39b7b91be46722789a0ce95ed5382405796077c..20a07dba6be04fb20f21bbac5ed1e289a8ccd354 100644 (file)
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -11,6 +11,7 @@
 #include <linux/hugetlb.h>
 #include <linux/slab.h>
 #include <linux/shm.h>
+#include <linux/ksm.h>
 #include <linux/mman.h>
 #include <linux/swap.h>
 #include <linux/capability.h>
@@ -174,6 +175,7 @@ static unsigned long move_vma(struct vm_area_struct *vma,
        unsigned long excess = 0;
        unsigned long hiwater_vm;
        int split = 0;
+       int err;
 
        /*
         * We'd prefer to avoid failure later on in do_munmap:
@@ -182,6 +184,18 @@ static unsigned long move_vma(struct vm_area_struct *vma,
        if (mm->map_count >= sysctl_max_map_count - 3)
                return -ENOMEM;
 
+       /*
+        * Advise KSM to break any KSM pages in the area to be moved:
+        * it would be confusing if they were to turn up at the new
+        * location, where they happen to coincide with different KSM
+        * pages recently unmapped.  But leave vma->vm_flags as it was,
+        * so KSM can come around to merge on vma and new_vma afterwards.
+        */
+       err = ksm_madvise(vma, old_addr, old_addr + old_len,
+                                               MADV_UNMERGEABLE, &vm_flags);
+       if (err)
+               return err;
+
        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)