[Intel-gfx] [PATCH 1/3] drm/i915: Use pagecache write to prepopulate shmemfs from pwrite-ioctl

[Chris Wilson]

On Tue, Mar 07, 2017 at 11:55:20AM +0200, Petri Latvala wrote:
> 
> For the record, manually launched extended test run on SKL
> resulted in:
> 
> commit f88cf1067cc499f4c9236c4e3ff7e410f9cc76d7
> Author: Chris Wilson <chris at chris-wilson.co.uk>
> Date:   Sat Mar 4 10:35:32 2017 +0000
> 
>     drm/i915: Use pagecache write to prepopulate shmemfs from pwrite-ioctl
> 
> 
> igt at gem_madvise@dontneed-before-exec: pass -> {'fail', 'incomplete'}
That test is expected to fail, that it ever passed is a fluke.
incomplete there should be a failure in the runner? That should quite
happily spot the purged object in execbuf.

> igt at gem_madvise@dontneed-before-pwrite: pass -> fail
Hmm. Here we are relying on shmemfs reporting the write to the truncated
object as invalid. Looks like we need to do the filtering ourselves. It
is not a huge problem as we still prevent any later instantiation of
pages so just a temporary slip. Setting obj->mm.pages = -EFAULT; is
likely a fun solution.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre