From: Nick Piggin <npiggin@suse.de>
Date: Wed, 22 Mar 2006 08:08:42 +0000 (-0800)
Subject: [PATCH] mm: more CONFIG_DEBUG_VM
X-Git-Tag: v2.6.17-rc1~1129^2~43
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b7ab795b7bec9997d4fde39f249d52823d36d98d;p=linux-2.6

[PATCH] mm: more CONFIG_DEBUG_VM

Put a few more checks under CONFIG_DEBUG_VM

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/mm/memory.c b/mm/memory.c
index 6af555c1c4..71bc664efe 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -388,7 +388,7 @@ struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, pte_
 {
 	unsigned long pfn = pte_pfn(pte);
 
-	if (vma->vm_flags & VM_PFNMAP) {
+	if (unlikely(vma->vm_flags & VM_PFNMAP)) {
 		unsigned long off = (addr - vma->vm_start) >> PAGE_SHIFT;
 		if (pfn == vma->vm_pgoff + off)
 			return NULL;
@@ -396,18 +396,12 @@ struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, pte_
 			return NULL;
 	}
 
-	/*
-	 * Add some anal sanity checks for now. Eventually,
-	 * we should just do "return pfn_to_page(pfn)", but
-	 * in the meantime we check that we get a valid pfn,
-	 * and that the resulting page looks ok.
-	 *
-	 * Remove this test eventually!
-	 */
+#ifdef CONFIG_DEBUG_VM
 	if (unlikely(!pfn_valid(pfn))) {
 		print_bad_pte(vma, pte, addr);
 		return NULL;
 	}
+#endif
 
 	/*
 	 * NOTE! We still have PageReserved() pages in the page 
diff --git a/mm/rmap.c b/mm/rmap.c
index 134aef9d66..1963e26931 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -56,13 +56,11 @@
 
 #include <asm/tlbflush.h>
 
-//#define RMAP_DEBUG /* can be enabled only for debugging */
-
 struct kmem_cache *anon_vma_cachep;
 
 static inline void validate_anon_vma(struct vm_area_struct *find_vma)
 {
-#ifdef RMAP_DEBUG
+#ifdef CONFIG_DEBUG_VM
 	struct anon_vma *anon_vma = find_vma->anon_vma;
 	struct vm_area_struct *vma;
 	unsigned int mapcount = 0;
@@ -551,13 +549,14 @@ void page_add_file_rmap(struct page *page)
 void page_remove_rmap(struct page *page)
 {
 	if (atomic_add_negative(-1, &page->_mapcount)) {
-		if (page_mapcount(page) < 0) {
+#ifdef CONFIG_DEBUG_VM
+		if (unlikely(page_mapcount(page) < 0)) {
 			printk (KERN_EMERG "Eeek! page_mapcount(page) went negative! (%d)\n", page_mapcount(page));
 			printk (KERN_EMERG "  page->flags = %lx\n", page->flags);
 			printk (KERN_EMERG "  page->count = %x\n", page_count(page));
 			printk (KERN_EMERG "  page->mapping = %p\n", page->mapping);
 		}
-
+#endif
 		BUG_ON(page_mapcount(page) < 0);
 		/*
 		 * It would be tidy to reset the PageAnon mapping here,