Is there SMP support in BIGMEM kernel?

batkinso · 09-08-2004, 03:08 PM

I am running Redhat 8 on a 4 cpu server with 4.5 Gb of Ram. Currently I am running the 2.4.20-27.8smp kernel, but the system does not seem to be using all of the memory. When I do cat /proc/meminfo this is what I see:

total: used: free:
Mem: 3963768832 3932069888 31698944

Is there SMP support in the Bigmem kernel, and if so, how do I turn it on? I am pretty new with Linux, so any help would be appreciated.

thanks,

Brian

Tinkster · 09-08-2004, 03:16 PM

The only way to find that out is to look at
that kernels .config ... or just try to run it.

If high-mem is set, but the step set to 4GB
the picture you get is quite likely, you'd have
to push it up a notch (64G) to make use of the
remaining 512M

Cheers,
Tink

batkinso · 09-08-2004, 03:31 PM

Okay, I don't mean to sound like a newbie, but where is the kernels.config, and where do I see where high-mem is set so I can change it?

thanks

Proud · 09-08-2004, 03:33 PM

Btw I think you mean BIGMEM support in the SMP kernel

dsegel · 09-08-2004, 04:49 PM

If you have the source for the kernel, the config file is at:

/usr/src/linux/.config

replace 'linux' with the actual direcotry containing the source if it's not already symlinked. You can go into that directory and do a 'make menuconfig' if you want to step through it nicely.

stickman · 09-08-2004, 09:06 PM

Quote:

Originally posted by batkinso
Is there SMP support in the Bigmem kernel, and if so, how do I turn it on? I am pretty new with Linux, so any help would be appreciated.

The bigmem kernel is for SMP systems with more than 4GB of memory.

batkinso · 09-09-2004, 05:21 AM

Thanks to all for the responses. Ya know, I thought BIGMEM was for SMP systems with over 4 Gb of memory, but when I booted the BIGMEM kernel last week, the system only saw 1 CPU, so I booted back into the SMP kernel, now I see all 4 CPU's but less than the 4.5 Gb of memory the system really has. That's why I was confused. Is there a switch or anything when booting the BIGMEM kernel so it sees all 4 CPU's AND 4.5 Gb of memory?

thanks

Mara · 09-09-2004, 07:18 AM

From what I see there's no RPM for RH 8 with both SMP and support of 64GB RAM. It means you'd need to compile it yourself. No matter if you start from BIGMEM or from SMP source, you'd have only one option to change. Do you have source of one of them?

amosf · 09-09-2004, 07:23 AM

Just compile. It's easy to do... During this recent 2.6.9 testing I've been compiling kernels a couple of times a day