Re: Shared memory management

[Ben Widawsky <ben@bwidawsk.net>]

On Thu, Mar 01, 2012 at 11:41:53AM -0500, Michal Mocny wrote:
> Hello,
> 
> I am trying to measure video memory usage as per Ben Widawsky's
> instructions from a while back:
> 
> mount debugfs
> cat /sys/kernel/debug/dri/0/i915_gem_gtt
> 
> However, the numbers are difficult to read/draw conclusions from.  Can I
> get some insight into the meaning of the various column values?
>  Specifically, if I would like to measure the actual current physical
> memory usage, should any of the values be ignored?
> 
> Thanks,
> -Michal

At the bottom you should see something like:
Total 370 objects, 35368960 bytes, 35368960 GTT size

The number in bytes (not sure offhand how it differs from GTT) is the
current physical memory usage of GEM objects. While it does not account
for internal data structures, or currently locked user pages (which
could be very large at various times), it is a good approximation.

I've since learned Eugeni Dodonov has written a tool to make this more
readable. I'm not sure what you get if you use that instead.

~Ben