Re: Linux 2.6.39 -- *ERROR* Attempting to mmap a purgeable buffer

[Mark Lord <kernel@teksavvy.com>]

On 11-05-20 06:00 PM, Linus Torvalds wrote:
> On Thu, May 19, 2011 at 8:26 AM, Mark Lord <kernel@teksavvy.com> wrote:
>>
>> Just got weird stuff in the syslog this morning from rc7-git12:
>>
>> [43190.824700] [drm:i915_gem_mmap_gtt] *ERROR* Attempting to mmap a purgeable buffer
>> [43190.827426] [drm:i915_gem_mmap_gtt] *ERROR* Attempting to mmap a purgeable buffer
>> [43190.827506] [drm:i915_gem_mmap_gtt] *ERROR* Attempting to mmap a purgeable buffer
>> [43190.827568] [drm:i915_gem_mmap_gtt] *ERROR* Attempting to mmap a purgeable buffer
>> [43190.828685] [drm:i915_gem_mmap_gtt] *ERROR* Attempting to mmap a purgeable buffer
>> [43190.830498] [drm:i915_gem_mmap_gtt] *ERROR* Attempting to mmap a purgeable buffer
>> [43190.830603] [drm:i915_gem_mmap_gtt] *ERROR* Attempting to mmap a purgeable buffer
>> [43190.831055] [drm:i915_gem_mmap_gtt] *ERROR* Attempting to mmap a purgeable buffer
>> [43190.832580] [drm:i915_gem_mmap_gtt] *ERROR* Attempting to mmap a purgeable buffer
>> [43190.832788] [drm:i915_gem_mmap_gtt] *ERROR* Attempting to mmap a purgeable buffer
> 
> Quoting from an earlier mail about this issue from the DRM people:
> 
>   "Userspace is attempting to write to/read from a buffer it has
> marked as being no longer required, so some rendering is going amiss.
> And it does not rule out the possibility that at some point it will
> catch the error later and result in a SIGBUS being sent to the
> application (probably X).
> 
>   However since it is not a kernel error nor is it fatal, that and a
> lot of similar messages can be demoted to debug."
> 
> So it's basically user space trying to access something stale, but it
> should be harmless.

Peachy.  I suspect the messages get generated when I run gmplayer or vlc
(not sure which, don't really care much either).

Thanks.