2021-12-10 19:50:24

by Bob Beckett

Subject: [PATCH] drm/i915/ttm: fix large buffer population trucation

ttm->num_pages is uint32_t which was causing very large buffers to
only populate a truncated size.

This fixes gem_create@create-clear igt test on large memory systems.

Fixes: 7ae034590cea ("drm/i915/ttm: add tt shmem backend")
Signed-off-by: Robert Beckett <[email protected]>
---
drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index 218a9b3037c7..923cc7ad8d70 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -166,7 +166,7 @@ static int i915_ttm_tt_shmem_populate(struct ttm_device *bdev,
struct intel_memory_region *mr = i915->mm.regions[INTEL_MEMORY_SYSTEM];
struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
const unsigned int max_segment = i915_sg_segment_size();
- const size_t size = ttm->num_pages << PAGE_SHIFT;
+ const size_t size = (size_t)ttm->num_pages << PAGE_SHIFT;
struct file *filp = i915_tt->filp;
struct sgt_iter sgt_iter;
struct sg_table *st;
--
2.25.1

2021-12-13 13:02:51

by Matthew Auld

Subject: Re: [PATCH] drm/i915/ttm: fix large buffer population trucation

On 10/12/2021 19:50, Robert Beckett wrote:
> ttm->num_pages is uint32_t which was causing very large buffers to
> only populate a truncated size.
>
> This fixes gem_create@create-clear igt test on large memory systems.
>
> Fixes: 7ae034590cea ("drm/i915/ttm: add tt shmem backend")
> Signed-off-by: Robert Beckett <[email protected]>

Nice catch,
Reviewed-by: Matthew Auld <[email protected]>

> ---
> drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> index 218a9b3037c7..923cc7ad8d70 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> @@ -166,7 +166,7 @@ static int i915_ttm_tt_shmem_populate(struct ttm_device *bdev,
> struct intel_memory_region *mr = i915->mm.regions[INTEL_MEMORY_SYSTEM];
> struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
> const unsigned int max_segment = i915_sg_segment_size();
> - const size_t size = ttm->num_pages << PAGE_SHIFT;
> + const size_t size = (size_t)ttm->num_pages << PAGE_SHIFT;
> struct file *filp = i915_tt->filp;
> struct sgt_iter sgt_iter;
> struct sg_table *st;
>

2021-12-14 14:52:40

by Matthew Auld

Subject: Re: [Intel-gfx] [PATCH] drm/i915/ttm: fix large buffer population trucation

On Mon, 13 Dec 2021 at 13:03, Matthew Auld <[email protected]> wrote:
>
> On 10/12/2021 19:50, Robert Beckett wrote:
> > ttm->num_pages is uint32_t which was causing very large buffers to
> > only populate a truncated size.
> >
> > This fixes gem_create@create-clear igt test on large memory systems.
> >
> > Fixes: 7ae034590cea ("drm/i915/ttm: add tt shmem backend")
> > Signed-off-by: Robert Beckett <[email protected]>
>
> Nice catch,
> Reviewed-by: Matthew Auld <[email protected]>

Pushed to drm-intel-gt-next. Thanks again for the fix.

>
> > ---
> > drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> > index 218a9b3037c7..923cc7ad8d70 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> > @@ -166,7 +166,7 @@ static int i915_ttm_tt_shmem_populate(struct ttm_device *bdev,
> > struct intel_memory_region *mr = i915->mm.regions[INTEL_MEMORY_SYSTEM];
> > struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
> > const unsigned int max_segment = i915_sg_segment_size();
> > - const size_t size = ttm->num_pages << PAGE_SHIFT;
> > + const size_t size = (size_t)ttm->num_pages << PAGE_SHIFT;
> > struct file *filp = i915_tt->filp;
> > struct sgt_iter sgt_iter;
> > struct sg_table *st;
> >