2002-12-07 04:24:21

by Z F

[permalink] [raw]
Subject: CPU cache problem

Hello everybody

Sorry to bother you with such a question, but I have a
Intel 1.7GHz Celeron processor with ASUS P4S533 motherboard.
The problem I have is that cat /proc/cpuinfo reports that

cache size : 20 KB

As far as I know, the CPU has 128K L2 cache.

The kernel version installed on my computer is 2.4.18.
I tried using cachesize=128 as a boot parameter, but it did not help.
L2 cache is enabled in BIOS.

Could someone tell me why it is happening, how to fix it and should I
be
worried that the motherboard is defective.

Thank you very much for your kind help

Lazar

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2002-12-07 04:30:32

by Manish Lachwani

[permalink] [raw]
Subject: RE: CPU cache problem

Did you check in the BIOS if there is an L2 cache size mentioned? Not every
BIOS supports it but you shoud check there ...

Thanks
-Manish

-----Original Message-----
From: Z F [mailto:[email protected]]
Sent: Friday, December 06, 2002 8:32 PM
To: [email protected]
Subject: CPU cache problem


Hello everybody

Sorry to bother you with such a question, but I have a
Intel 1.7GHz Celeron processor with ASUS P4S533 motherboard.
The problem I have is that cat /proc/cpuinfo reports that

cache size : 20 KB

As far as I know, the CPU has 128K L2 cache.

The kernel version installed on my computer is 2.4.18.
I tried using cachesize=128 as a boot parameter, but it did not help.
L2 cache is enabled in BIOS.

Could someone tell me why it is happening, how to fix it and should I
be
worried that the motherboard is defective.

Thank you very much for your kind help

Lazar

__________________________________________________
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2002-12-07 18:33:08

by Z F

[permalink] [raw]
Subject: RE: CPU cache problem

Hello Manish and Mark

The BIOS does not have any info about L2 cache accept for
enable/disable
switch.
I noticed that after the POST message in the table of all installed
devices it said CPU 1.7 GHz... Memory installed 256 M (RAM) and
CPU cache: NONE.

I have upgraded the BIOS on the system and now it says 128K, as it
should, according to CPU specifications.
Mark tells that /proc/cpuinfo reports L1 cache size (which I assume is
8K+12 K in my case, even though I do not understand what that means)
But how to check that L2 is operational?

For windows I have ASUSprobe software, which after the BIOS upgrade
started to report that CPU has L2 cache, but it reports it regardless
of BIOS switch(enable/disable) as if program simply reads the CPU
specifications. (Before BIOS upgrade it reported 0K L2 cache.)

The question I have is: Is it possible to tell whether or not
the kernel sees the L2 CPU cache and its size?

Thank you very much for your help

Lazar


--- Manish Lachwani <[email protected]> wrote:
> Did you check in the BIOS if there is an L2 cache size mentioned? Not
> every
> BIOS supports it but you shoud check there ...
>
> Thanks
> -Manish
>
> -----Original Message-----
> From: Z F [mailto:[email protected]]
> Sent: Friday, December 06, 2002 8:32 PM
> To: [email protected]
> Subject: CPU cache problem
>
>
> Hello everybody
>
> Sorry to bother you with such a question, but I have a
> Intel 1.7GHz Celeron processor with ASUS P4S533 motherboard.
> The problem I have is that cat /proc/cpuinfo reports that
>
> cache size : 20 KB
>
> As far as I know, the CPU has 128K L2 cache.
>
> The kernel version installed on my computer is 2.4.18.
> I tried using cachesize=128 as a boot parameter, but it did not help.
> L2 cache is enabled in BIOS.
>
> Could someone tell me why it is happening, how to fix it and should I
> be
> worried that the motherboard is defective.
>
> Thank you very much for your kind help
>
> Lazar
>
> __________________________________________________
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> Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
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2002-12-07 23:08:27

by J.A. Magallon

[permalink] [raw]
Subject: Re: CPU cache problem


On 2002.12.07 Z F wrote:
>Hello Manish and Mark
>
>The BIOS does not have any info about L2 cache accept for
>enable/disable
>switch.
>I noticed that after the POST message in the table of all installed
>devices it said CPU 1.7 GHz... Memory installed 256 M (RAM) and
>CPU cache: NONE.
>
>I have upgraded the BIOS on the system and now it says 128K, as it
>should, according to CPU specifications.
>Mark tells that /proc/cpuinfo reports L1 cache size (which I assume is
>8K+12 K in my case, even though I do not understand what that means)
>But how to check that L2 is operational?
>
>For windows I have ASUSprobe software, which after the BIOS upgrade
>started to report that CPU has L2 cache, but it reports it regardless
>of BIOS switch(enable/disable) as if program simply reads the CPU
>specifications. (Before BIOS upgrade it reported 0K L2 cache.)
>
>The question I have is: Is it possible to tell whether or not
>the kernel sees the L2 CPU cache and its size?
>

Supposing you have a recent kernel with cpuid support, try x86info,
at least it will tell you what processor-bios is reporting (ala your
ASUS utility).

To see what the kernel thinks about the processor, cat /proc/cpuinfo.
The cache reported there is L2.

Hope this helps.

--
J.A. Magallon <[email protected]> \ Software is like sex:
werewolf.able.es \ It's better when it's free
Mandrake Linux release 9.1 (Cooker) for i586
Linux 2.4.20-jam1 (gcc 3.2 (Mandrake Linux 9.1 3.2-4mdk))

2002-12-08 17:33:26

by Dave Jones

[permalink] [raw]
Subject: Re: CPU cache problem

On Fri, Dec 06, 2002 at 08:31:58PM -0800, Z F wrote:
> Hello everybody
>
> Sorry to bother you with such a question, but I have a
> Intel 1.7GHz Celeron processor with ASUS P4S533 motherboard.
> The problem I have is that cat /proc/cpuinfo reports that
>
> cache size : 20 KB
>
> As far as I know, the CPU has 128K L2 cache.
>
> The kernel version installed on my computer is 2.4.18.

This bug is fixed in Marcelo's current tree, fix will be in 2.4.20pre1

> I tried using cachesize=128 as a boot parameter, but it did not help.

Also a fix for a different bug where this gets used too late.

Dave

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

2002-12-08 17:43:31

by Dave Jones

[permalink] [raw]
Subject: Re: CPU cache problem

On Sun, Dec 08, 2002 at 05:38:16PM +0000, Dave Jones wrote:
> > As far as I know, the CPU has 128K L2 cache.
> > The kernel version installed on my computer is 2.4.18.
> This bug is fixed in Marcelo's current tree, fix will be in 2.4.20pre1

*sigh, long weekend..* I meant 2.4.21pre1 of course.
You can also find the patch at
ftp://ftp.kernel.org/pub/linux/kernel/people/davej/patches/2.4/2.4.20/descriptors.diff


Dave

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