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From: Dave Jones <davej@redhat.com>
To: Andrew Morton <akpm@osdl.org>
Cc: nickpiggin@yahoo.com.au, linux-kernel@vger.kernel.org
Subject: Re: mm/rmap.c negative page map count BUG.
Date: Wed, 4 Jan 2006 19:31:08 -0500	[thread overview]
Message-ID: <20060105003108.GC30967@redhat.com> (raw)
In-Reply-To: <20060104161640.08a53c3f.akpm@osdl.org>

On Wed, Jan 04, 2006 at 04:16:40PM -0800, Andrew Morton wrote:
 > Dave Jones <davej@redhat.com> wrote:
 > >
 > > +			printk (KERN_EMERG "Eeek! page_mapcount(page) went negative! (%d)\n", page->_mapcount);
 > 
 > page_mapcount(page);
 > 
 > > +			printk (KERN_EMERG "  page->flags = %x\n", page->flags);
 > 
 > %lx
 > 
 > > +			printk (KERN_EMERG "  page->count = %x\n", page->_count);
 > 
 > page_count(page);

Ugh, almost an error per line. I suck.

		Dave

--- linux-2.6.14/mm/rmap.c~	2006-01-03 08:53:32.000000000 -0500
+++ linux-2.6.14/mm/rmap.c	2006-01-03 08:58:19.000000000 -0500
@@ -484,6 +484,13 @@ void page_remove_rmap(struct page *page)
 	BUG_ON(PageReserved(page));
 
 	if (atomic_add_negative(-1, &page->_mapcount)) {
+		if (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_ON(page_mapcount(page) < 0);
 		/*
 		 * It would be tidy to reset the PageAnon mapping here,

  reply	other threads:[~2006-01-05  0:31 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-01-03  8:26 mm/rmap.c negative page map count BUG Dave Jones
2006-01-03 11:42 ` Nick Piggin
2006-01-03 13:53   ` Dave Jones
2006-01-04 23:53     ` Andrew Morton
2006-01-04 23:56       ` Dave Jones
2006-01-05  0:16         ` Andrew Morton
2006-01-05  0:31           ` Dave Jones [this message]
2006-01-05  7:47       ` Dave Jones
2006-01-05  8:11         ` Arjan van de Ven
2006-01-05 11:15           ` Dave Jones
2006-01-05 11:18             ` Arjan van de Ven
2006-01-05 11:26               ` Dave Jones
2006-01-05 19:00             ` Octavio Alvarez
2006-01-11  8:01               ` Octavio Alvarez Piza
2006-01-11 16:12                 ` Hugh Dickins
2006-01-11 16:21                   ` Arjan van de Ven
2006-01-11 16:58                   ` Octavio Alvarez Piza
2006-01-11 17:18                     ` Hugh Dickins
2006-01-11 17:24                     ` Andrew Morton

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