[PATCH] drm/amdgpu: add shared fdinfo stats
Rob Clark
robdclark at gmail.com
Thu Nov 30 15:58:38 UTC 2023
On Thu, Nov 30, 2023 at 5:13 AM Christian König
<ckoenig.leichtzumerken at gmail.com> wrote:
>
> Am 28.11.23 um 18:52 schrieb Rob Clark:
> > On Tue, Nov 28, 2023 at 6:28 AM Alex Deucher <alexdeucher at gmail.com> wrote:
> >> On Tue, Nov 28, 2023 at 9:17 AM Christian König
> >> <ckoenig.leichtzumerken at gmail.com> wrote:
> >>> Am 17.11.23 um 20:56 schrieb Alex Deucher:
> >>>> Add shared stats. Useful for seeing shared memory.
> >>>>
> >>>> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> >>>> ---
> >>>> drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c | 4 ++++
> >>>> drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 11 +++++++++++
> >>>> drivers/gpu/drm/amd/amdgpu/amdgpu_object.h | 6 ++++++
> >>>> 3 files changed, 21 insertions(+)
> >>>>
> >>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c
> >>>> index 5706b282a0c7..c7df7fa3459f 100644
> >>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c
> >>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c
> >>>> @@ -97,6 +97,10 @@ void amdgpu_show_fdinfo(struct drm_printer *p, struct drm_file *file)
> >>>> stats.requested_visible_vram/1024UL);
> >>>> drm_printf(p, "amd-requested-gtt:\t%llu KiB\n",
> >>>> stats.requested_gtt/1024UL);
> >>>> + drm_printf(p, "drm-shared-vram:\t%llu KiB\n", stats.vram_shared/1024UL);
> >>>> + drm_printf(p, "drm-shared-gtt:\t%llu KiB\n", stats.gtt_shared/1024UL);
> >>>> + drm_printf(p, "drm-shared-cpu:\t%llu KiB\n", stats.cpu_shared/1024UL);
> >>>> +
> >>>> for (hw_ip = 0; hw_ip < AMDGPU_HW_IP_NUM; ++hw_ip) {
> >>>> if (!usage[hw_ip])
> >>>> continue;
> >>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> >>>> index d79b4ca1ecfc..c24f7b2c04c1 100644
> >>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> >>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> >>>> @@ -1287,25 +1287,36 @@ void amdgpu_bo_get_memory(struct amdgpu_bo *bo,
> >>>> struct amdgpu_mem_stats *stats)
> >>>> {
> >>>> uint64_t size = amdgpu_bo_size(bo);
> >>>> + struct drm_gem_object *obj;
> >>>> unsigned int domain;
> >>>> + bool shared;
> >>>>
> >>>> /* Abort if the BO doesn't currently have a backing store */
> >>>> if (!bo->tbo.resource)
> >>>> return;
> >>>>
> >>>> + obj = &bo->tbo.base;
> >>>> + shared = obj->handle_count > 1;
> >>> Interesting approach but I don't think that this is correct.
> >>>
> >>> The handle_count is basically how many GEM handles are there for BO, so
> >>> for example it doesn't catch sharing things with V4L.
> >>>
> >>> What we should probably rather do is to take a look if
> >>> bo->tbo.base.dma_buf is NULL or not.
> >> +Rob, dri-devel
> >>
> >> This is what the generic drm helper code does. See
> >> drm_show_memory_stats(). If that is not correct that code should
> >> probably be fixed too.
> > OTOH, v4l doesn't expose fdinfo. What "shared" is telling you is
> > whether the BO is counted multiple times when you look at all
> > processes fdinfo.
>
> Oh, then that's not fully correct either.
>
> You can have multiple handles for the same GEM object in a single client
> as well.
>
> This for example happens when you interact with KMS to get an handle for
> a displayed BO.
so, the handle is unique per drm_file which is (at least usually)
unique per process. The handle_count is agnostic to _how_ you got the
handle (ie. via flink or dma-buf)
> DRM flink was one of the major other reasons, but I hope we are not
> using that widely any more.
>
> What exactly is the purpose? To avoid counting a BO multiple times
> because you go over the handles in the common code?
>
> If yes than I would say use obj->handle_count in the common code and
> ob->dma_buf in amdgpu because that is certainly unique.
Because the drm_file is (usually) unique per process, the purpose was
to show the amount of memory that is getting counted against multiple
processes. The intention behind using handle_count was just that it
didn't care _how_ the buffer was shared, just that it is mapped into
more than a single drm_file.
Maybe amd userspace is doing something unique that I'm not aware of?
BR,
-R
> Regards,
> Christian.
>
> >
> > But I guess it would be ok to look for obj->handle_count > 1 || obj->dma_buf
> >
> > BR,
> > -R
> >
> >> Alex
> >>
> >>> Regards,
> >>> Christian.
> >>>
> >>>
> >>>> +
> >>>> domain = amdgpu_mem_type_to_domain(bo->tbo.resource->mem_type);
> >>>> switch (domain) {
> >>>> case AMDGPU_GEM_DOMAIN_VRAM:
> >>>> stats->vram += size;
> >>>> if (amdgpu_bo_in_cpu_visible_vram(bo))
> >>>> stats->visible_vram += size;
> >>>> + if (shared)
> >>>> + stats->vram_shared += size;
> >>>> break;
> >>>> case AMDGPU_GEM_DOMAIN_GTT:
> >>>> stats->gtt += size;
> >>>> + if (shared)
> >>>> + stats->gtt_shared += size;
> >>>> break;
> >>>> case AMDGPU_GEM_DOMAIN_CPU:
> >>>> default:
> >>>> stats->cpu += size;
> >>>> + if (shared)
> >>>> + stats->cpu_shared += size;
> >>>> break;
> >>>> }
> >>>>
> >>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> >>>> index d28e21baef16..0503af75dc26 100644
> >>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> >>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> >>>> @@ -138,12 +138,18 @@ struct amdgpu_bo_vm {
> >>>> struct amdgpu_mem_stats {
> >>>> /* current VRAM usage, includes visible VRAM */
> >>>> uint64_t vram;
> >>>> + /* current shared VRAM usage, includes visible VRAM */
> >>>> + uint64_t vram_shared;
> >>>> /* current visible VRAM usage */
> >>>> uint64_t visible_vram;
> >>>> /* current GTT usage */
> >>>> uint64_t gtt;
> >>>> + /* current shared GTT usage */
> >>>> + uint64_t gtt_shared;
> >>>> /* current system memory usage */
> >>>> uint64_t cpu;
> >>>> + /* current shared system memory usage */
> >>>> + uint64_t cpu_shared;
> >>>> /* sum of evicted buffers, includes visible VRAM */
> >>>> uint64_t evicted_vram;
> >>>> /* sum of evicted buffers due to CPU access */
>
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