L2 Cache problem

L2 Cache problem

[Xavier LaRue]

Hi all,

My linux kernel did'nt detect my L2 cache on any of my two cpu ( this is an smp box ) here is the /proc/cpuinfo:
Therse processor are perfect Steping match SL3FJ( therse old katmai processor have 512k l2 cache ).

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 7
model name      : Pentium III (Katmai)
stepping        : 3
cpu MHz         : 549.070
cache size      : 32 KB
[...]
processor       : 1
vendor_id       : GenuineIntel
cpu family      : 6
model           : 7
model name      : Pentium III (Katmai)
stepping        : 3
cpu MHz         : 549.070
cache size      : 32 KB

And I get nothing in my dmesg about l2 cache ( 'dmesg | grep L2' give nothing )
I'm on an plain vanilla kernel ( 2.4.18 taken at kernel.org ) with xfs-1.1 patch.
At boot my bios say that my L2 of my two cpu are ok.

my dmesg will be online at http://paxl.no-ip.org/~paxl/dmesg.txt if somone mind.


Another fuzzy thing .. compiling my kernel normaly ( -j 1 ) take 30min and when I make it with -j 2/8/16 it take 25min, I think this is due to my L2 cache problem but that not normal, if somone have an idea.. I should be realy interested.

Another little detail that could help you, my mother board is an AMI MegaRUM II(that a dual p2/p3 mobo).

I hope somone will have an solution.
Thank you for your time
Xavier LaRue

Re: L2 Cache problem

[Marc-Christian Petersen]

On Monday 16 December 2002 19:30, Xavier LaRue wrote:

Hi Xavier,

> My linux kernel did'nt detect my L2 cache on any of my two cpu ( this is an
> smp box ) here is the /proc/cpuinfo: Therse processor are perfect Steping
> match SL3FJ( therse old katmai processor have 512k l2 cache ).
> And I get nothing in my dmesg about l2 cache ( 'dmesg | grep L2' give
> nothing ) I'm on an plain vanilla kernel ( 2.4.18 taken at kernel.org )
> with xfs-1.1 patch. At boot my bios say that my L2 of my two cpu are ok.
This is fixed in 2.4.21-pre1. You have to upgrade or play with this patch:

http://linux.bkbits.net:8080/linux-2.4/cset@1.757.30.17?nav=index.html|ChangeSet@-3w

I am afraid this will not apply clean ontop of 2.4.18.

ciao, Marc

Re: L2 Cache problem

[Mike Dresser]

On Mon, 16 Dec 2002, Xavier LaRue wrote:

> my dmesg will be online at http://paxl.no-ip.org/~paxl/dmesg.txt if somone mind.
>
>
> Another fuzzy thing .. compiling my kernel normaly ( -j 1 ) take 30min
> and when I make it with -j 2/8/16 it take 25min, I think this is due to
> my L2 cache problem but that not normal, if somone have an idea.. I
> should be realy interested.

sounds like you've got your l2 turned off in the bios to me.

Mike

Re: L2 Cache problem

[Dave Jones]

On Mon, Dec 16, 2002 at 01:56:09PM -0500, Mike Dresser wrote:
 > > my dmesg will be online at http://paxl.no-ip.org/~paxl/dmesg.txt if somone mind.
 > > Another fuzzy thing .. compiling my kernel normaly ( -j 1 ) take 30min
 > > and when I make it with -j 2/8/16 it take 25min, I think this is due to
 > > my L2 cache problem but that not normal, if somone have an idea.. I
 > > should be realy interested.
 > sounds like you've got your l2 turned off in the bios to me.

2.4 right up until .21pre1 has a bug in the cache sizing routine.
It should be fixed now.

		Dave

-- 
| Dave Jones.        http://www.codemonkey.org.uk
| SuSE Labs

Re: L2 Cache problem

[Xavier LaRue]

On Mon, 16 Dec 2002 13:56:09 -0500 (EST)
Mike Dresser <mdresser_l@windsormachine.com> wrote:

> On Mon, 16 Dec 2002, Xavier LaRue wrote:
> 
> > my dmesg will be online at http://paxl.no-ip.org/~paxl/dmesg.txt if somone mind.
> >
> >
> > Another fuzzy thing .. compiling my kernel normaly ( -j 1 ) take 30min
> > and when I make it with -j 2/8/16 it take 25min, I think this is due to
> > my L2 cache problem but that not normal, if somone have an idea.. I
> > should be realy interested.
> 
> sounds like you've got your l2 turned off in the bios to me.

There is no option in my bios to enable or disable L2 cache..
And at boot I get this

DSP Microcode OK ...... L2 512KB OK
AS#1 Microcode OK ...... L2 512KB OK

So I assume that the bios enable it, do there is a way to Force the kernel to use it even if he can't detect it ??

Thank you for your time and answer :)
Xavier LaRue