[PATCH] freepgt: remove MM_VM_SIZE(mm)

There's only one usage of MM_VM_SIZE(mm) left, and it's a troublesome macro
because mm doesn't contain the (32-bit emulation?) info needed.  But it too is
only needed because we ignore the end from the vma list.

We could make flush_pgtables return that end, or unmap_vmas.  Choose the
latter, since it's a natural fit with unmap_mapping_range_vma needing to know
its restart addr.  This does make more than minimal change, but if unmap_vmas
had returned the end before, this is how we'd have done it, rather than
storing the break_addr in zap_details.

unmap_vmas used to return count of vmas scanned, but that's just debug which
hasn't been useful in a while; and if we want the map_count 0 on exit check
back, it can easily come from the final remove_vm_struct loop.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index 926d03015471..f8c61b2385ff 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1900,6 +1900,7 @@ void exit_mmap(struct mm_struct *mm)
         struct mmu_gather *tlb;
         struct vm_area_struct *vma = mm->mmap;
         unsigned long nr_accounted = 0;
+        unsigned long end;
 
         lru_add_drain();
 
@@ -1908,10 +1909,10 @@ void exit_mmap(struct mm_struct *mm)
         flush_cache_mm(mm);
         tlb = tlb_gather_mmu(mm, 1);
         /* Use -1 here to ensure all VMAs in the mm are unmapped */
-        mm->map_count -= unmap_vmas(&tlb, mm, vma, 0, -1, &nr_accounted, NULL);
+        end = unmap_vmas(&tlb, mm, vma, 0, -1, &nr_accounted, NULL);
         vm_unacct_memory(nr_accounted);
         free_pgtables(&tlb, vma, 0, 0);
-        tlb_finish_mmu(tlb, 0, MM_VM_SIZE(mm));
+        tlb_finish_mmu(tlb, 0, end);
 
         mm->mmap = mm->mmap_cache = NULL;
         mm->mm_rb = RB_ROOT;
@@ -1931,7 +1932,6 @@ void exit_mmap(struct mm_struct *mm)
                 vma = next;
         }
 
-        BUG_ON(mm->map_count);  /* This is just debugging */
         BUG_ON(mm->nr_ptes);    /* This is just debugging */
 }