From 01ff53f416757da416413bc32229770a8448b6ef Mon Sep 17 00:00:00 2001
From: Mike Frysinger <vapier@gentoo.org>
Date: Tue, 23 Jun 2009 12:37:01 -0700
Subject: [PATCH] rmap: fixup page_referenced() for nommu systems
After the recent changes that went into mm/vmscan.c to overhaul stuff, we
ended up with these warnings on no-mmu systems:
mm/vmscan.c: In function `shrink_page_list':
mm/vmscan.c:580: warning: unused variable `vm_flags'
mm/vmscan.c: In function `shrink_active_list':
mm/vmscan.c:1294: warning: `vm_flags' may be used uninitialized in this function
mm/vmscan.c:1242: note: `vm_flags' was declared here
This is because the no-mmu function defines page_referenced() to work on
the first argument only (the page). It does not clear the vm_flags given
to it because for no-mmu systems, they never actually get utilized. Since
that is no longer strictly true, we need to set vm_flags to 0 like
everyone else so gcc can do proper dead code elimination without annoying
us with unused warnings.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: David Howells <dhowells@redhat.com>
Acked-by: David McCullough <davidm@snapgear.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
include/linux/rmap.h | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 216d024f830d2..bf116d0dbf23f 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -118,7 +118,14 @@ int try_to_munlock(struct page *);
#define anon_vma_prepare(vma) (0)
#define anon_vma_link(vma) do {} while (0)
-#define page_referenced(page, locked, cnt, flags) TestClearPageReferenced(page)
+static inline int page_referenced(struct page *page, int is_locked,
+ struct mem_cgroup *cnt,
+ unsigned long *vm_flags)
+{
+ *vm_flags = 0;
+ return TestClearPageReferenced(page);
+}
+
#define try_to_unmap(page, refs) SWAP_FAIL
static inline int page_mkclean(struct page *page)
--
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