memory use in 5336 driver

[csh]

Normally, my X server uses about 265MB of virtual memory. Loading a
game like Infiltration, or heavy 3D application makes it grow to
over 300MB at times. After exiting the application, X virtual process
size stayed at its maximum size.

That is standard behavior for most UNIX processes. The more addresses
a program requests, the more it is given, and they are only returned to
the OS if your application explicitly unmaps them. Not all OS can even
do that.

Since upgrading the driver, I noticed things had improved all around, so
today I took a good look at X memory use. Things have changed...

Now my X server uses an average of 76MB. Playing Infiltration moves
virtual size to 98MB. Exiting the game causes virtual size to shrink
back to 76MB.

It even shrinks after using things like The Gimp, and other image
programs.

I am wondering what nVidia did in this driver that makes such a big difference.

Has anyone else seen this on their system?

[Andy Mecham]

There's a blurb about memory usage under X in the readme. Search for "Why does X use so much memory?".

--andy

[csh]

Originally posted by Andy Mecham
There's a blurb about memory usage under X in the readme. Search for "Why does X use so much memory?".

--andy

It looks like you didn't read or understand my post.

The README doesn't answer any question in my post. I understand normal X memory usage and why it is so high.

My point is that the high memory use has gone away in the 5336, and I can find no explanation for why that is. Something major has changed in the new driver versus the old.

[zander]

Take a look at the server's viritual memory map, chances are the NVIDIA driver simply doesn't unconditionally map all of the installed video memory any more; a similar change was made to the kernel component of the driver at some point in the past: the NVIDIA driver used to exhaust the kernel's virtual address space with video memory and register mappings.

[csh]

Originally posted by zander
Take a look at the server's viritual memory map, chances are the NVIDIA driver simply doesn't unconditionally map all of the installed video memory any more; a similar change was made to the kernel component of the driver at some point in the past: the NVIDIA driver used to exhaust the kernel's virtual address space with video memory and register mappings.

That's likely, and it fits with that I see from memory use and checking the process mapping in detail. I thought I saved pmap and my own memory program's output for the
older driver, but now I can't find it to compare, and changing drivers is currently highly inconvienient.

I was hoping someone from nVidia could give a definitive answer.

If someone with one of the older drivers wants to post the output of pmap, that would be cool.