128MB lost... where ?

128MB lost... where ?

[Giuliano Pochini]

Perhaps this is a faq...
I have a dual-800 (mb asus, no AGP) with 1GB ram,
but according to /proc/meminfo tells I only have
900000KB. I tried "mem=1024" boot parameter without
success. How can I get my 128MB back ?


Bye.
    Giuliano Pochini ->)|(<- Shiny Corporation {AS6665} ->)|(<-

RE: 128MB lost... where ?

[Davide Libenzi]

On 21-Feb-2001 Giuliano Pochini wrote:
> 
> Perhaps this is a faq...
> I have a dual-800 (mb asus, no AGP) with 1GB ram,
> but according to /proc/meminfo tells I only have
> 900000KB. I tried "mem=1024" boot parameter without
> success. How can I get my 128MB back ?

Check Your BIOS setting coz some motherboards reserves main memory fog AGP.



- Davide

 

Re: 128MB lost... where ?

[Tigran Aivazian]

On Wed, 21 Feb 2001, Giuliano Pochini wrote:

> 
> Perhaps this is a faq...
> I have a dual-800 (mb asus, no AGP) with 1GB ram,
> but according to /proc/meminfo tells I only have
> 900000KB. I tried "mem=1024" boot parameter without
> success. How can I get my 128MB back ?
> 

when you compile your 2.4.x kernel make sure you set the "4G of RAM"
option, i.e. CONFIG_HIGHMEM4G. If you chose "up to 1G" then it means "up
to 986M" (or something like that) -- the number in Help is just rounded up
to confuse the dummy user :)

Regards,
Tigran

Re: 128MB lost... where ?

[Tigran Aivazian]

On Wed, 21 Feb 2001, Tigran Aivazian wrote:

> On Wed, 21 Feb 2001, Giuliano Pochini wrote:
> 
> > 
> > Perhaps this is a faq...
> > I have a dual-800 (mb asus, no AGP) with 1GB ram,
> > but according to /proc/meminfo tells I only have
> > 900000KB. I tried "mem=1024" boot parameter without
> > success. How can I get my 128MB back ?
> > 
> 
> when you compile your 2.4.x kernel make sure you set the "4G of RAM"
> option, i.e. CONFIG_HIGHMEM4G. If you chose "up to 1G" then it means "up
> to 986M" (or something like that) -- the number in Help is just rounded up
     ~~~

not 986M but (unsigned long)(-PAGE_OFFSET-VMALLOC_RESERVE)>>20 MB which is
around 876M or so.

Regards,
Tigran

Re: 128MB lost... where ?

[Richard B. Johnson]

On Wed, 21 Feb 2001, Giuliano Pochini wrote:

> 
> Perhaps this is a faq...
> I have a dual-800 (mb asus, no AGP) with 1GB ram,
> but according to /proc/meminfo tells I only have
> 900000KB. I tried "mem=1024" boot parameter without
> success. How can I get my 128MB back ?
> 
> 
> Bye.
>     Giuliano Pochini ->)|(<- Shiny Corporation {AS6665} ->)|(<-
> 

You can't. You have to enable HIGHMEM4G in `make config`, then
rebuild the entire kernel. This doesn't work well with 2.4.1 because
many modules will have unresolved symbols. Maybe this has been
fixed in a later kernel.


Cheers,
Dick Johnson

Penguin : Linux version 2.4.1 on an i686 machine (799.53 BogoMips).

"Memory is like gasoline. You use it up when you are running. Of
course you get it all back when you reboot..."; Actual explanation
obtained from the Micro$oft help desk.

RE: 128MB lost... where ?

[Desjardins, Kristian]

> On Wed, 21 Feb 2001, Tigran Aivazian wrote:
> 
> > 
> > when you compile your 2.4.x kernel make sure you set the "4G of RAM"
> > option, i.e. CONFIG_HIGHMEM4G. If you chose "up to 1G" then 
> it means "up
> > to 986M" (or something like that) -- the number in Help is 
> just rounded up
>      ~~~
> 
> not 986M but (unsigned 
> long)(-PAGE_OFFSET-VMALLOC_RESERVE)>>20 MB which is
> around 876M or so.
> 

I also have a question about RAM. I am running 2.4.2pre4 on Dell Poweredge
6400 with 6.4GB of RAM (12x512MB + 4x64MB). With 4GB support free reports
3597324 total, and with 64GB support it reports about ~5.9GB.  I also have
another problem, when using 64GB large_mem support, the system will
sometimes oops (I haven't captured one yet) or completely hang when I run
out of physical memory. Swap does not even get touched (8GB swap, 4 x 2GB,
why can I only use 2GB swap partitions?)

/proc/meminfo

        total:    used:    free:  shared: buffers:  cached:
Mem:  3683659776 510230528 3173429248        0  1044480 458235904
Swap: 4144005120 169009152 3974995968
MemTotal:      3597324 kB
MemFree:       3099052 kB
MemShared:           0 kB
Buffers:          1020 kB
Cached:         447496 kB
Active:           3324 kB
Inact_dirty:    170156 kB
Inact_clean:    275036 kB
Inact_target:        4 kB
HighTotal:     2752504 kB
HighFree:      2351772 kB
LowTotal:       844820 kB
LowFree:        747280 kB
SwapTotal:     8241184 kB
SwapFree:      8076136 kB

RE: 128MB lost... where ?

[Tigran Aivazian]

Hi,

free is not an interesting command. Much more interesting is the kernel
messages on boot, e.g. on my laptop it looks like this:

BIOS-provided physical RAM map:
 BIOS-e820: 000000000009fc00 @ 0000000000000000 (usable)
 BIOS-e820: 0000000000000400 @ 000000000009fc00 (reserved)
 BIOS-e820: 000000000000c000 @ 00000000000c0000 (reserved)
 BIOS-e820: 0000000007ef0000 @ 0000000000100000 (usable)
 BIOS-e820: 0000000000010000 @ 0000000007ff0000 (ACPI data)
 BIOS-e820: 0000000000060000 @ 00000000100a0000 (reserved)
 BIOS-e820: 0000000000200000 @ 00000000ffe00000 (reserved)
On node 0 totalpages: 32752
zone(0): 4096 pages.
zone(1): 28656 pages.
zone(2): 0 pages.
Kernel command line: auto BOOT_IMAGE=241 ro root=302
BOOT_FILE=/boot/vmlinuz-2.4.1
Initializing CPU#0
Detected 448.628 MHz processor.
Console: colour VGA+ 80x25
Calibrating delay loop... 894.56 BogoMIPS
kdb version 1.7 by Scott Lurndal, Keith Owens. Copyright SGI, All Rights
Reserved
Memory: 125696k/131008k available (1311k kernel code, 4924k reserved, 949k
data, 184k init, 0k highm
em)

as you can see, the above tells you exactly how many pages you have in
each zone and the total number of usable pages. But even that is not
relevant to your question. What is relevant is the number after the first
"/" in the "Memory:" line and also the BIOS-e820 map, of course.

Also, on 6.4G machine you should definitely use 64G i.e. PAE support and
so if not all memory is detected, please report to this list. People like
David Parsons will probably be interested in your configuration...

Regards,
Tigran

RE: 128MB lost... where ?

[Desjardins, Kristian]

> as you can see, the above tells you exactly how many pages you have in
> each zone and the total number of usable pages. But even that is not
> relevant to your question. What is relevant is the number 
> after the first
> "/" in the "Memory:" line and also the BIOS-e820 map, of course.
> 
> Also, on 6.4G machine you should definitely use 64G i.e. PAE 
> support and
> so if not all memory is detected, please report to this list. 
> People like
> David Parsons will probably be interested in your configuration...
> 
> Regards,
> Tigran
> 

Thanks, the problem was that I never saw the beginning of the kernel output
(dmesg) until I attached a PC and used it as a serial console.

Memory: 5917096k/6553600k available (1504k kernel code, 111824k reserved,
555k d

Re: 128MB lost... where ?

[Giuliano Pochini]

>when you compile your 2.4.x kernel make sure you set the "4G of RAM"
>option, i.e. CONFIG_HIGHMEM4G. If you chose "up to 1G" then it means "up
>to 986M" (or something like that) -- the number in Help is just rounded up
>to confuse the dummy user :)

Ok, I tried it, but it doesn't boot. It doesn't show errors during
init, but then it can't execute anything. The boot sequence stops with
"cannot exec modprobe...." repeated hundreds times.
Yes, modutils are the latest version.

(ASUS cur-dls, dual-833. It runs a Slackware 7.1 + some updates.
Kernel 2.4.2-SMP compiled with egcs-2.91.66.)


Bye.
    Giuliano Pochini ->)|(<- Shiny Corporation {AS6665} ->)|(<-