[PATCH] move rmap BUG_ON outside DEBUG_VM (b16bc64d) · Commits · 戴 / test

We have a persistent dribble of reports of this BUG triggering. Its extended diagnostics were recently made conditional on CONFIG_DEBUG_VM, which was a bad idea - we want to know about it. Signed-off-by:

Dave Jones <davej@redhat.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by:

Andrew Morton <akpm@osdl.org> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

mm/rmap.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -576,15 +576,14 @@ void page_add_file_rmap(struct page *page)
		void page_remove_rmap(struct page *page)
		{
		if (atomic_add_negative(-1, &page->_mapcount)) {
		#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);
		BUG();
		}
		#endif
		BUG_ON(page_mapcount(page) < 0);

		/*
		* It would be tidy to reset the PageAnon mapping here,
		* but that might overwrite a racing page_add_anon_rmap

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