[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>
diff --git a/mm/fremap.c b/mm/fremap.c
index ab23a06..fd7f2a1 100644
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -39,7 +39,7 @@
set_page_dirty(page);
page_remove_rmap(page);
page_cache_release(page);
- dec_mm_counter(mm, rss);
+ dec_mm_counter(mm, file_rss);
}
}
} else {
@@ -95,7 +95,7 @@
zap_pte(mm, vma, addr, pte);
- inc_mm_counter(mm,rss);
+ inc_mm_counter(mm, file_rss);
flush_icache_page(vma, page);
set_pte_at(mm, addr, pte, mk_pte(page, prot));
page_add_file_rmap(page);