On Thu, Nov 21, 2019 at 09:02:59AM +0100, Gerd Hoffmann wrote:
> Hi,
>
> > > update-object-after-move works fine.
> > >
> > > try zap mappings with madvise(dontneed) has no bad effects (after vram
> > > move, trying to force re-creating the ptes).
> >
> > Well if it's broken the zapping wouldn't work :-)
> >
> > > didn't try the memory pressure thing yet.
> >
> > I'm surprised ... and I have no idea how/why it keeps working.
> >
> > For my paranoia, can you instrument the ttm page fault handler, and double
> > check that we get new faults after the move, and set up new ptes for the
> > same old mapping, but now pointing at the new place in vram?
>
> Hmm, only the drm device mapping is faulted in after moving it,
> the dma-buf mapping is not. Fixed by:
Ah yes, that's more what I'd expect to happen, and the below is what I'd
expect to fix things up. I think we should move it up ahead of the device
callback (so that drivers can overwrite) and then push as a fix. Separate
from a possible patch to undo the fake offset removal.
-Daniel
>
> -------------------------- cut here ------------------------
> From 3a7f6c6dbf3b1e4b412c2b283b2ea4edff9f33b5 Mon Sep 17 00:00:00 2001
> From: Gerd Hoffmann <kraxel@xxxxxxxxxx>
> Date: Thu, 21 Nov 2019 08:39:17 +0100
> Subject: [PATCH] drm: share address space for dma bufs
>
> ---
> drivers/gpu/drm/drm_prime.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
> index 0814211b0f3f..07c88d2aedee 100644
> --- a/drivers/gpu/drm/drm_prime.c
> +++ b/drivers/gpu/drm/drm_prime.c
> @@ -240,6 +240,7 @@ void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv)
> struct dma_buf *drm_gem_dmabuf_export(struct drm_device *dev,
> struct dma_buf_export_info *exp_info)
> {
> + struct drm_gem_object *obj = exp_info->priv;
> struct dma_buf *dma_buf;
>
> dma_buf = dma_buf_export(exp_info);
> @@ -247,7 +248,8 @@ struct dma_buf *drm_gem_dmabuf_export(struct drm_device *dev,
> return dma_buf;
>
> drm_dev_get(dev);
> - drm_gem_object_get(exp_info->priv);
> + drm_gem_object_get(obj);
> + dma_buf->file->f_mapping = obj->dev->anon_inode->i_mapping;
>
> return dma_buf;
> }
> --
> 2.18.1
>
> -------------------------- cut here ------------------------
>
> git branch: https://git.kraxel.org/cgit/linux/log/?h=drm-mmap-debug
>
> cheers,
> Gerd
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel
