Re: Fusion-MPT much faster as module

From: Holger Kiehl
Date: Tue Mar 22 2005 - 03:33:30 EST


On Mon, 21 Mar 2005, Andrew Morton wrote:

Holger Kiehl <Holger.Kiehl@xxxxxx> wrote:

Hello

On a four CPU Opteron compiling the Fusion-MPT as module gives much better
performance when compiling it in, here some bonnie++ results:

Version 1.03 ------Sequential Output------ --Sequential Input- --Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
compiled in 15872M 38366 71 65602 22 18348 4 53276 84 57947 7 905.4 2
module 15872M 51246 96 204914 70 57236 14 59779 96 264171 33 923.0 2

This happens with 2.6.10, 2.6.11 and 2.6.11-bk2. Controller is a
Symbios Logic 53c1030 PCI-X Fusion-MPT Dual Ultra320 SCSI.

Why is there such a large difference?


Holger, this problem remains unresolved, does it not? Have you done any
more experimentation?

No. For now I just leave it as module.

I must say that something funny seems to be happening here. I have two
MPT-based Dell machines, neither of which is using a modular driver:


akpm:/usr/src/25> 0 hdparm -t /dev/sda

/dev/sda:
Timing buffered disk reads: 64 MB in 5.00 seconds = 12.80 MB/sec

Got the same result when compiled in, always between 12 and 13 MB/s. As
module it is approx. 75 MB/s.

Hope that LSI Logic will find the problem.

Another question I have is there a way in what SCSI mode (320, 160, etc)
Fusion-MPT is running? Could not find anything in proc or dmesg. Adaptec
has the following information in dmesg (and more in proc):

(scsi1:A:0): 320.000MB/s transfers (160.000MHz DT|IU|QAS, 16bit)

Or has the Fusion-MPT some other tool to show this information?

Holger
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