Possible radeon-related kernel memory leak

[Hubert Kario]

On Thursday 07 of February 2013 10:12:34 Michel Dänzer wrote:
> On Mit, 2013-02-06 at 22:02 +0100, Hubert Kario wrote:
> > I've noticed that my main desktop, after about 4-5 days of uptime,
> > becomes more and more sluggish. After investigating the issue a bit
> > I've discovered that kernel itself takes more memory.
> > 
> > Right after logging in, `smem -wtk` reports:
> > $ smem -wtk -R 4G -K /boot/vmlinuz-linux-mainline
> > Area                           Used      Cache   Noncache
> > firmware/hardware            135.8M          0     135.8M
> > kernel image                   3.5M          0       3.5M
> > kernel dynamic memory          1.1G     932.9M     171.1M
> > userspace memory             792.7M     168.4M     624.2M
> > free memory                    2.0G       2.0G          0
> > ----------------------------------------------------------
> > 
> >                                4.0G       3.1G     934.6M
> > 
> > But after the system's been up for a week, the report looks quite
> > different: $ smem -wtk -R 4G -K /boot/vmlinuz-linux-mainline
> > Area                           Used      Cache   Noncache
> > firmware/hardware            135.8M          0     135.8M
> > kernel image                   3.5M          0       3.5M
> > kernel dynamic memory          2.0G       1.1G    1012.2M
> > userspace memory               1.7G     177.2M       1.5G
> > free memory                  149.8M     149.8M          0
> > ----------------------------------------------------------
> > 
> >                                4.0G       1.4G       2.6G
> > 
> > The interesting bit is that it's enough to kill X and log in back again
> > to make the system fast again.
> 
> That means the leak is more likely in userspace than in the kernel. Is
> it enough to kill any processes using r600_dri.so, in particular any
> compositing manager using OpenGL, to reclaim the memory?

No, restarting kwin (by `kwin --replace`) does not reclaim the memory.
I have to kill X to to reclaim it.

The memory is allocated by kernel, the 
noncache kernel dynamic memory is equal to total memory size reduced by 
cache, buffers and userspace allocations.

Even if I turn off all applications and restart kwin, it's still at 1G.

Regards,
-- 
Hubert Kario