Disable SMI on new BMC?

Russell Johnson rjohnson at rtlogic.com
Wed May 16 14:07:58 CDT 2007

> -----Original Message-----
> From: Michael E Brown [mailto:Michael_E_Brown at dell.com] 
> Sent: Wednesday, May 16, 2007 12:52 PM
> To: Russell Johnson
> Cc: linux-poweredge at dell.com
> Subject: Re: Disable SMI on new BMC?

> SMIs would be related to BIOS version as much as anything. I 
> hear that IBM is working on updated BIOS to remove as many 
> SMIs as possible specifically for real-time use. I dont think 
> the Dell BIOS guys are on board with that yet. As far as I 
> know, there is no way to disable SMIs (I could be wrong, 
> though, it happens)

Older systems had a way, I could flip a bit at PMBase + 0x30 of device bus
0, device 1f, function 0 (PCI) and completely disable SMI.  These new
systems don't seem to follow that same model.

> Check the BIOS versions between the two sets of machines. 
> I'll bet that if you flash the newer machines with the same 
> BIOS rev as the old machines, you might see your problems go away.

I've actually already tried this.  I flashed the new system backwards for
all firmware/bios versions that were visible to me and it still had the long
latencies.  Then I flashed the old system forwards to the latest versions
and it still has short latencies.  This leads me to believe there is some
firmware/hardware/etc that has changed under the covers.  I'm hopeful that I
can disable something to get my real time performance back.

My old 2900 had firmware/BIOS versions as follows (<60us latency)

DELL BIOS                   1.2.0
RAID BIOS                   5.0.3-0001
Remote Access Config Util   1.03
Baseboard Mgt Controller    1.14
Primary Backplane Firmware  1.00

My new 2900 had firmware versions as follows (>2ms latency)

DELL BIOS                   1.3.7
RAID BIOS                   5.1.1-0040
Remote Access Config Util   1.03
Baseboard Mgt Controller    1.33
Primary Backplane Firmware  1.05

Thanks for the help.
Any other ideas?

Russell Johnson
RT Logic! 

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