2010-11-14 18:33:37

by Uros Bizjak

[permalink] [raw]
Subject: [PATCH v3, x86]: Use selfsnoop HW feature to manage conflicting memory types

Hello!

Attached patch enhances v2 patch at [1] to disable selfsnoop with a
kernel command line parameter. The feature is also disabled on all
processors earlier than Core 2 due to Pentium-M errata.

I have investigated the erratas in this area and documented the one
found in the source.

The patch was tested on 4 core i7 (8 threads) and there were no
problems at all with the patched kernel.

[1] http://lkml.org/lkml/2009/4/8/508

Signed-off-by: Uros Bizjak <[email protected]>


Attachments:
selfsnoop.patch (3.11 kB)

2010-11-14 20:37:35

by Uros Bizjak

[permalink] [raw]
Subject: Re: [PATCH v3, x86]: Use selfsnoop HW feature to manage conflicting memory types

On Sun, Nov 14, 2010 at 7:33 PM, Uros Bizjak <[email protected]> wrote:
> Hello!
>
> Attached patch enhances v2 patch at [1] to disable selfsnoop with a
> kernel command line parameter. The feature is also disabled on all
> processors earlier than Core 2 due to Pentium-M errata.
>
> I have investigated the erratas in this area and documented the one
> found in the source.
>
> The patch was tested on 4 core i7 (8 threads) and there were no
> problems at all with the patched kernel.

Also, I'd like to point out that similar change was introduced in
FreeBSD as part of r195749 in July 2009, see [1].

[1] http://svn.freebsd.org/viewvc/base?view=revision&revision=195749

Uros.