F7 64bit 4G Memory

[Srikanth Konjarla]

After the installation, does the Kernel see 4G RAM?

Giancarlo del Rossi wrote:
> Check the kernel version and update.
> 
> If in any case the problems persist, make a simply test with the last 
> kernel version 2.6.21.5
> 
> With 4 Gbyte of ram i have a problems on sata controller because that 
> dont recognize the HD device, but i fixed with the kernel upgrade.
> 
> Look here:
> 
> https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=242969
> 
> Bye
> 
> Giancarlo
> 
> 
> Marcelo de Souza Sant'Anna ha scritto:
> 
> 
>> Read this too:
>>
>> http://fedora.kiewel-online.de/repoview/linux/releases/7/Everything/i386/repodata/repoview/kernel-PAE-0-2.6.21-1.3194.fc7.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 at gmail.com <mailto:srikanth.konjarla at 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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> Giancarlo del Rossi
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