RE: [PATCH V2 RESEND] fsl-sata: I/O load balancing

-----Original Message-----
From: linuxppc-dev-bounces+tie-fei.zang=3Dfreescale.com@lists.ozlabs.org
[mailto:linuxppc-dev-bounces+tie-fei.zang=3Dfreescale.com@lists.ozlabs.or=

g]

On Behalf Of Benjamin Herrenschmidt
Sent: Friday, February 17, 2012 11:19 AM
To: Li Yang-R58472
Cc: Liu Qiang-B32616; jgarzik@pobox.com; linuxppc-dev@lists.ozlabs.org;
linux-kernel@vger.kernel.org; linux-ide@vger.kernel.org
Subject: RE: [PATCH V2 RESEND] fsl-sata: I/O load balancing
=20
On Fri, 2012-02-17 at 03:09 +0000, Li Yang-R58472 wrote:

quoted

quoted

I tried a debian install on the p5020ds here and I find SATA to be
extremely slow, generating millions of interrupts. I think the

defaults

quoted

should be a lot more aggressive at coalescing.

The P5020 has a hardware problem with SATA, making it generate more
interrupts than it should.  A new revision of the silicon will fix it.

=20
Ok cool. With a bit of luck you guys can send me a new silicon when it's
available then :-) (The one in the board you got me seems to be in a
socket).

Ben,
We still do not have the a P5020 sample to fix the problem.
One workaround is to use the patch ( I think you have noticed the patch):
http://git.freescale.com/git/cgit.cgi/ppc/sdk/linux.git/commit/?id=3D92c0ce=
1e599e788ffc0908739db9bd5e0dbdad69

and  use a SSD hard drive.
It will have a usable performance.
Thanks.
Roy