linux-kernel - Re: [PATCH v4 10/10] thp: implement refcounting for huge zero page

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 24 Oct 2012 13:25:52 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Cc:	"Kirill A. Shutemov" <kirill@...temov.name>,
	Andrea Arcangeli <aarcange@...hat.com>, linux-mm@...ck.org,
	Andi Kleen <ak@...ux.intel.com>,
	"H. Peter Anvin" <hpa@...ux.intel.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 10/10] thp: implement refcounting for huge zero page

On Wed, 24 Oct 2012 22:45:52 +0300
"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com> wrote:

> On Wed, Oct 24, 2012 at 12:22:53PM -0700, Andrew Morton wrote:
> > 
> > I'm thinking that such a workload would be the above dd in parallel
> > with a small app which touches the huge page and then exits, then gets
> > executed again.  That "small app" sounds realistic to me.  Obviously
> > one could exercise the zero page's refcount at higher frequency with a
> > tight map/touch/unmap loop, but that sounds less realistic.  It's worth
> > trying that exercise as well though.
> > 
> > Or do something else.  But we should try to probe this code's
> > worst-case behaviour, get an understanding of its effects and then
> > decide whether any such workload is realisic enough to worry about.
> 
> Okay, I'll try few memory pressure scenarios.

Thanks.

> Meanwhile, could you take patches 01-09? Patch 09 implements simpler
> allocation scheme. It would be nice to get all other code tested.
> Or do you see any other blocker?

I think I would take them all, to get them tested while we're still
poking at the code.  It's a matter of getting my lazy ass onto reviewing
the patches.

The patches have a disturbing lack of reviewed-by's, acked-by's and
tested-by's on them.  Have any other of the MM lazy asses actually
spent some time with them yet?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/