Re: [ 101/175] mm: vmscan: forcibly scan highmem if there are toomany buffer_heads pinning highmem

From: Mel Gorman
Date: Thu Apr 05 2012 - 16:35:15 EST


Sorry for the slow response. I was at LSF/MM and still at Collaboration
Summit and not keeping up with mail.

On Tue, Apr 03, 2012 at 04:01:33AM +0100, Ben Hutchings wrote:

> On Fri, 2012-03-30 at 12:50 -0700, Greg KH wrote:
> > 3.3-stable review patch. If anyone has any objections, please let me know.
> >
> > ------------------
> >
> > From: Mel Gorman <mel@xxxxxxxxx>
> >
> > commit cc715d99e529d470dde2f33a6614f255adea71f3 upstream.
> >
> > Stuart Foster reported on bugzilla that copying large amounts of data
> > from NTFS caused an OOM kill on 32-bit X86 with 16G of memory. Andrew
> > Morton correctly identified that the problem was NTFS was using 512
> > blocks meaning each page had 8 buffer_heads in low memory pinning it.
>
> I notice that this was not applied to 3.0.26 or 3.2.14.
>

True.

> [...]
> > Addresses https://bugzilla.kernel.org/show_bug.cgi?id=42578
> [...]
>
> but this bug was reported against 3.1.9, so the fix is presumably needed
> for 3.2 at least.
>
> Presumably the upstream change doesn't apply cleanly and would need to
> be backported. Is anyone planning to do that?
>

It probably does not apply cleanly and considering how the bug is
triggered I was not treating it as a high priority. Nikola Ciprich
(added to cc) had said that he might try backporting it and I would
review the result. I have not heard anything since. I can take a look at
backporting it next week if it is considered a common problem.

--
Mel Gorman
SUSE Labs
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/