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References: <20211210195005.2582884-1-bob.beckett@collabora.com> <e7cad6ca-d106-c529-6f22-93a7847cd7c0@intel.com>
In-Reply-To: <e7cad6ca-d106-c529-6f22-93a7847cd7c0@intel.com>
From:   Matthew Auld <matthew.william.auld@gmail.com>
Date:   Tue, 14 Dec 2021 14:52:08 +0000
Message-ID: <CAM0jSHNn4yq1u_Qwr9v9kUCcEexBmb+=LML2=OF1Rspyf-TDfA@mail.gmail.com>
Subject: Re: [Intel-gfx] [PATCH] drm/i915/ttm: fix large buffer population trucation
To:     Matthew Auld <matthew.auld@intel.com>
Cc:     Robert Beckett <bob.beckett@collabora.com>,
        Jani Nikula <jani.nikula@linux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@intel.com>,
        Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        =?UTF-8?Q?Thomas_Hellstr=C3=B6m?= 
        <thomas.hellstrom@linux.intel.com>, Oak Zeng <oak.zeng@intel.com>,
        Intel Graphics Development <intel-gfx@lists.freedesktop.org>,
        kernel list <linux-kernel@vger.kernel.org>,
        ML dri-devel <dri-devel@lists.freedesktop.org>
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Precedence: bulk

On Mon, 13 Dec 2021 at 13:03, Matthew Auld <matthew.auld@intel.com> 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 <bob.beckett@collabora.com>
>
> Nice catch,
> Reviewed-by: Matthew Auld <matthew.auld@intel.com>

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;
> >