[PATCH] mm: rss = file_rss + anon_rss

I was lazy when we added anon_rss, and chose to change as few places as
possible.  So currently each anonymous page has to be counted twice, in rss
and in anon_rss.  Which won't be so good if those are atomic counts in some
configurations.

Change that around: keep file_rss and anon_rss separately, and add them
together (with get_mm_rss macro) when the total is needed - reading two
atomics is much cheaper than updating two atomics.  And update anon_rss
upfront, typically in memory.c, not tucked away in page_add_anon_rmap.

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, 1 insertions, 1 deletions

diff --git a/fs/exec.c b/fs/exec.c
index d2208f7c87db..cefadf5ab83b 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -330,7 +330,7 @@ void install_arg_page(struct vm_area_struct *vma,
                 pte_unmap(pte);
                 goto out;
         }
-        inc_mm_counter(mm, rss);
+        inc_mm_counter(mm, anon_rss);
         lru_cache_add_active(page);
         set_pte_at(mm, address, pte, pte_mkdirty(pte_mkwrite(mk_pte(
                                         page, vma->vm_page_prot))));