incorrect memory size reported

tintapok · 10-28-2005, 02:59 PM

Hi folks,
Recently I've installed the new Slackware 10.2 with kernel 2.6.13. Now the problem is, that although I have 1GB RAM, Slackware reports only 906108KB RAM. This is wierd, because the bios, and a knoppix which I've tried reported correctly the amount of RAM.
Any ideas, what should I check further?
Thank you,
T.

Tinkster · 10-28-2005, 03:07 PM

That's because slacks default kernel isn't compiled with
high-memory support. You'll need to recompile your kernel
with the appropriate setting changed.

Cheers,
Tink

nilleso · 10-28-2005, 03:11 PM

Your kernel likely doesn't have CONFIG_HIGHMEM flagged

Refer to here as an example (there are many more)... where it states:

It is advised to not enable CONFIG_HIGHMEM in the kernel to utilize
the extra 128 MB you get for your 1 GB RAM system. I/O Devices cannot
directly address high memory from PCI space, so bounce buffers have to
be used. Plus the virtual memory management and paging costs come with
extra mappings.

If you do a `dmesg|grep HIGHMEM` you'll probably see something like the following:

Code:

Jun 7 23:36:30 hostname kernel: Warning only 896MB will be used.
Jun 7 23:36:30 hostname kernel: Use a HIGHMEM enabled kernel.

cheers

tintapok · 10-29-2005, 01:11 AM

All right, thank you.
T.