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Re: F7 64bit 4G Memory



Try use the kernel-PAE!

Read a section 9.3 this document:

http://mirror.atrpms.net/fedora/linux/releases/7/Fedora/i386/os/RELEASE-NOTES-en_US.html



On Mon, 2007-07-02 at 22:37 -0400, Srikanth Konjarla wrote:
Thanks for the response. Interestingly, i could not find any BIOS 
options pertaining to memory.

I found the following.

# cat /proc/mtrr
reg00: base=0xfeda0000 (4077MB), size= 128KB: write-back, count=1
reg01: base=0xfff00000 (4095MB), size=   1MB: write-protect, count=1
reg02: base=0x00000000 (   0MB), size=2048MB: write-back, count=1
reg03: base=0x80000000 (2048MB), size=1024MB: write-back, count=1
reg04: base=0xc0000000 (3072MB), size= 256MB: write-back, count=1

Could be incompatible memory modules or something?

Thanks

Srikanth

Wolfgang S. Rupprecht wrote:
> Srikanth Konjarla <srikanth konjarla gmail com> writes:
>> I am running F7 in 64-bit mode on a laptop. I have upgraded the memory
>> from 3G to 4G (Bios confirms it) but kernel sees only 3.2G (i have
>> passed mem=4096M kernel parameter). Wondering if i am missing anything
>> here.
> 
> What you are missing is the really nasty design of IBM-PC legacy
> memory allocations.  ;-)
> 
> Play around in your BIOS and see if you can map the excess memory
> above 4GB.  Often the labels for the settings will have the term
> "MTRR" in the name.  When you get it right "cat /proc/mtrr" should
> show the extra 750MBytes mapped above 4 Gigs.  The setting names might
> not make much sense (at least they don't on my Tyan).  You might need
> to just try them all and see what effect they have on the linux mttr
> settings.  Here is what it looks like on my board when I have it set
> to see all 4 GBytes:
> 
> $ cat /proc/mtrr 
> reg00: base=0x00000000 (   0MB), size=2048MB: write-back, count=1
> reg01: base=0x80000000 (2048MB), size=1024MB: write-back, count=1
> reg02: base=0xc0000000 (3072MB), size= 256MB: write-back, count=1
> reg03: base=0xcff00000 (3327MB), size=   1MB: uncachable, count=1
> reg04: base=0x100000000 (4096MB), size= 512MB: write-back, count=1
> reg05: base=0x120000000 (4608MB), size= 256MB: write-back, count=1
> reg06: base=0xd8000000 (3456MB), size= 128MB: write-combining, count=2
> 
> Notice the first 3 entries are 3.25 GBytes (reg00, reg01 and reg02).
> The last 0.75GBytes are mapped above 4GByte (reg04 and reg05).
> 
> -wolfgang


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