lkml.org 
[lkml]   [2000]   [Nov]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Memory management bug
On Fri, Nov 17, 2000 at 05:35:53PM +0100, schwidefsky@de.ibm.com wrote:
> I did a little closer investigation. The BUG was triggered by a page with
> page->mapping pointing to an address space of a mapped ext2 file
> (page->mapping->a_ops == &ext2_aops). The page had PG_locked, PG_uptodate,
> PG_active and PG_swap_cache set. The stack backstrace showed that kswapd
> called do_try_to_free_pages, refill_inactive, swap_out, swap_out_mm,
> swap_out_vma, try_to_swap_out and add_to_swap_cache where BUG hit. The
> registers look good, the struct page looks good. I don't think that this was
> a random memory corruption.

Agreed, that's almost sure _not_ random memory corruption of the page
structure. It looks like a VM bug (if you can reproduce trivially I'd give a
try to test8 too since test8 is rock solid for me while test10 lockups in VM
core at the second bonnie if using emulated highmem).

> I was refering to the "if (!order) goto try_again" ifs in alloc_pages, not
> the "if (something) BUG()" ifs.

Ah ok :), see Linus's answer: in your case the "don't do that" means to
implement the:

#define SOFT_PAGE_SIZE (PAGE_SIZE<<2)

thing we were talking about yesterday of course.

Plus I add that the "if (!order) goto try_again" is an obvious deadlock prone
bug introduce in test9 that should be removed.

Andrea
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 12:47    [W:0.071 / U:14.220 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site