Possible radeon-related kernel memory leak

[Michel Dänzer]

On Don, 2013-02-14 at 12:03 +0100, Hubert Kario wrote: 
> On Wednesday 13 of February 2013 11:51:00 Michel Dänzer wrote:
> > On Die, 2013-02-12 at 22:54 +0100, Hubert Kario wrote:
> > > On Monday 11 of February 2013 13:00:41 Michel Dänzer wrote:
> > > > On Son, 2013-02-10 at 15:01 +0100, Hubert Kario wrote:
> > > > > > > Even if I turn off all applications and restart kwin, it's still
> > > > > > > at
> > > > > > > 1G.
> > > > > > 
> > > > > > xlsclients only lists kwin at that point, no other clients?
> > > > > 
> > > > > no, there's still the plasma desktop, krunner, probably something
> > > > > else...
> > > > 
> > > > Have you tried killing those?
> > > 
> > > If I have the problem next time, I'll try restarting or killing
> > > everything that shows up in xlsclients
> > > 
> > > Is there any specific data you want to see before and after killing
> > > those
> > > applications? And before and after killing X (without system restart) if
> > > restarting X clients doesn't resolve the issue?
> > 
> > Not sure offhand what to look at other than the numbers you've posted.
> > 
> > But really, if the memory is reclaimed when X dies, by definition it's
> > not leaked in the kernel.
> 
> It depends on how you define leaked.
> 
> In this case I define "leak" as memory that can't be used actively by kernel 
> or userspace, not necessarily memory we don't have references for.

The point is that the kernel only keeps track of and recovers memory
allocated on behalf of userspace in the first place.


> While it's not technically a leak, it has all the side effects of a real 
> leak.

You can only recover actually leaked kernel memory by rebooting.


> > > > > [drm:radeon_cs_ioctl] ERROR Failed to parse relocation -12
> > > > > 
> > > > > Can't this cause leaks of kernel memory that are freed only on full
> > > > > X
> > > > > re-
> > > > > initialisation?
> > > > 
> > > > These errors are symptoms of running out of kernel memory, probably
> > > > not
> > > > the cause of it.
> > > 
> > > Thing is, when I'm playing the game in question I turn off everything
> > > besides the KDE services and background daemons, so I have close to
> > > 3.5GiB of free memory.
> > 
> > You could be running into
> > https://bugzilla.kernel.org/show_bug.cgi?id=49981
> 
> This very much looks like it. Now, should I go and compile mesa from git

That would certainly be interesting.

> or still try to reach 1G of noncache kernel dynamic memory (I'm at  800M)...

Does that make any difference? What matters is whether it decreases
significantly when a certain process dies.


-- 
Earthling Michel Dänzer           |                   http://www.amd.com
Libre software enthusiast         |          Debian, X and DRI developer