On 14/03/2022 22:42, Dmitry Osipenko wrote:
> Replace Panfrost's memory shrinker with a generic DRM memory shrinker.
>
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
> ---
I gave this a spin on my Firefly-RK3288 board and everything seems to
work. So feel free to add a:
Tested-by: Steven Price <steven.price@xxxxxxx>
As Alyssa has already pointed out you need to remove the
panfrost_gem_shrinker.c file. But otherwise everything looks fine, and
I'm very happy to see the shrinker code gone ;)
Thanks,
Steve
> drivers/gpu/drm/panfrost/Makefile | 1 -
> drivers/gpu/drm/panfrost/panfrost_device.h | 4 ----
> drivers/gpu/drm/panfrost/panfrost_drv.c | 19 ++-------------
> drivers/gpu/drm/panfrost/panfrost_gem.c | 27 ++++++++++++++--------
> drivers/gpu/drm/panfrost/panfrost_gem.h | 9 --------
> drivers/gpu/drm/panfrost/panfrost_job.c | 22 +++++++++++++++++-
> 6 files changed, 40 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/Makefile b/drivers/gpu/drm/panfrost/Makefile
> index b71935862417..ecf0864cb515 100644
> --- a/drivers/gpu/drm/panfrost/Makefile
> +++ b/drivers/gpu/drm/panfrost/Makefile
> @@ -5,7 +5,6 @@ panfrost-y := \
> panfrost_device.o \
> panfrost_devfreq.o \
> panfrost_gem.o \
> - panfrost_gem_shrinker.o \
> panfrost_gpu.o \
> panfrost_job.o \
> panfrost_mmu.o \
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
> index 8b25278f34c8..fe04b21fc044 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.h
> @@ -115,10 +115,6 @@ struct panfrost_device {
> atomic_t pending;
> } reset;
>
> - struct mutex shrinker_lock;
> - struct list_head shrinker_list;
> - struct shrinker shrinker;
> -
> struct panfrost_devfreq pfdevfreq;
> };
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> index 94b6f0a19c83..b014dadcf51f 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> @@ -160,7 +160,6 @@ panfrost_lookup_bos(struct drm_device *dev,
> break;
> }
>
> - atomic_inc(&bo->gpu_usecount);
> job->mappings[i] = mapping;
> }
>
> @@ -390,7 +389,6 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
> {
> struct panfrost_file_priv *priv = file_priv->driver_priv;
> struct drm_panfrost_madvise *args = data;
> - struct panfrost_device *pfdev = dev->dev_private;
> struct drm_gem_object *gem_obj;
> struct panfrost_gem_object *bo;
> int ret = 0;
> @@ -403,7 +401,6 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
>
> bo = to_panfrost_bo(gem_obj);
>
> - mutex_lock(&pfdev->shrinker_lock);
> mutex_lock(&bo->mappings.lock);
> if (args->madv == PANFROST_MADV_DONTNEED) {
> struct panfrost_gem_mapping *first;
> @@ -429,17 +426,8 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
>
> args->retained = drm_gem_shmem_madvise(&bo->base, args->madv);
>
> - if (args->retained) {
> - if (args->madv == PANFROST_MADV_DONTNEED)
> - list_add_tail(&bo->base.madv_list,
> - &pfdev->shrinker_list);
> - else if (args->madv == PANFROST_MADV_WILLNEED)
> - list_del_init(&bo->base.madv_list);
> - }
> -
> out_unlock_mappings:
> mutex_unlock(&bo->mappings.lock);
> - mutex_unlock(&pfdev->shrinker_lock);
>
> drm_gem_object_put(gem_obj);
> return ret;
> @@ -570,9 +558,6 @@ static int panfrost_probe(struct platform_device *pdev)
> ddev->dev_private = pfdev;
> pfdev->ddev = ddev;
>
> - mutex_init(&pfdev->shrinker_lock);
> - INIT_LIST_HEAD(&pfdev->shrinker_list);
> -
> err = panfrost_device_init(pfdev);
> if (err) {
> if (err != -EPROBE_DEFER)
> @@ -594,7 +579,7 @@ static int panfrost_probe(struct platform_device *pdev)
> if (err < 0)
> goto err_out1;
>
> - panfrost_gem_shrinker_init(ddev);
> + drm_gem_shmem_shrinker_register(ddev);
>
> return 0;
>
> @@ -612,8 +597,8 @@ static int panfrost_remove(struct platform_device *pdev)
> struct panfrost_device *pfdev = platform_get_drvdata(pdev);
> struct drm_device *ddev = pfdev->ddev;
>
> + drm_gem_shmem_shrinker_unregister(ddev);
> drm_dev_unregister(ddev);
> - panfrost_gem_shrinker_cleanup(ddev);
>
> pm_runtime_get_sync(pfdev->dev);
> pm_runtime_disable(pfdev->dev);
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
> index 293e799e2fe8..d164d05ed84e 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
> @@ -19,16 +19,6 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
> struct panfrost_gem_object *bo = to_panfrost_bo(obj);
> struct panfrost_device *pfdev = obj->dev->dev_private;
>
> - /*
> - * Make sure the BO is no longer inserted in the shrinker list before
> - * taking care of the destruction itself. If we don't do that we have a
> - * race condition between this function and what's done in
> - * panfrost_gem_shrinker_scan().
> - */
> - mutex_lock(&pfdev->shrinker_lock);
> - list_del_init(&bo->base.madv_list);
> - mutex_unlock(&pfdev->shrinker_lock);
> -
> /*
> * If we still have mappings attached to the BO, there's a problem in
> * our refcounting.
> @@ -195,6 +185,22 @@ static int panfrost_gem_pin(struct drm_gem_object *obj)
> return drm_gem_shmem_pin(&bo->base);
> }
>
> +static unsigned long panfrost_gem_purge(struct drm_gem_object *obj)
> +{
> + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
> + struct panfrost_gem_object *bo = to_panfrost_bo(obj);
> +
> + if (!mutex_trylock(&bo->mappings.lock))
> + return 0;
> +
> + panfrost_gem_teardown_mappings_locked(bo);
> + drm_gem_shmem_purge_locked(&bo->base);
> +
> + mutex_unlock(&bo->mappings.lock);
> +
> + return shmem->base.size >> PAGE_SHIFT;
> +}
> +
> static const struct drm_gem_object_funcs panfrost_gem_funcs = {
> .free = panfrost_gem_free_object,
> .open = panfrost_gem_open,
> @@ -207,6 +213,7 @@ static const struct drm_gem_object_funcs panfrost_gem_funcs = {
> .vunmap = drm_gem_shmem_object_vunmap,
> .mmap = drm_gem_shmem_object_mmap,
> .vm_ops = &drm_gem_shmem_vm_ops,
> + .purge = panfrost_gem_purge,
> };
>
> /**
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
> index 8088d5fd8480..09da064f1c07 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
> @@ -30,12 +30,6 @@ struct panfrost_gem_object {
> struct mutex lock;
> } mappings;
>
> - /*
> - * Count the number of jobs referencing this BO so we don't let the
> - * shrinker reclaim this object prematurely.
> - */
> - atomic_t gpu_usecount;
> -
> bool noexec :1;
> bool is_heap :1;
> };
> @@ -84,7 +78,4 @@ panfrost_gem_mapping_get(struct panfrost_gem_object *bo,
> void panfrost_gem_mapping_put(struct panfrost_gem_mapping *mapping);
> void panfrost_gem_teardown_mappings_locked(struct panfrost_gem_object *bo);
>
> -void panfrost_gem_shrinker_init(struct drm_device *dev);
> -void panfrost_gem_shrinker_cleanup(struct drm_device *dev);
> -
> #endif /* __PANFROST_GEM_H__ */
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> index a6925dbb6224..e767e526e897 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -267,6 +267,22 @@ static void panfrost_attach_object_fences(struct drm_gem_object **bos,
> dma_resv_add_excl_fence(bos[i]->resv, fence);
> }
>
> +static bool panfrost_objects_alive(struct drm_gem_object **bos, int bo_count)
> +{
> + struct panfrost_gem_object *bo;
> + bool alive = true;
> +
> + while (alive && bo_count--) {
> + bo = to_panfrost_bo(bos[bo_count]);
> +
> + mutex_lock(&bo->mappings.lock);
> + alive = !bo->base.madv;
> + mutex_unlock(&bo->mappings.lock);
> + }
> +
> + return alive;
> +}
> +
> int panfrost_job_push(struct panfrost_job *job)
> {
> struct panfrost_device *pfdev = job->pfdev;
> @@ -278,6 +294,11 @@ int panfrost_job_push(struct panfrost_job *job)
> if (ret)
> return ret;
>
> + if (!panfrost_objects_alive(job->bos, job->bo_count)) {
> + ret = -ENOMEM;
> + goto unlock;
> + }
> +
> mutex_lock(&pfdev->sched_lock);
> drm_sched_job_arm(&job->base);
>
> @@ -319,7 +340,6 @@ static void panfrost_job_cleanup(struct kref *ref)
> if (!job->mappings[i])
> break;
>
> - atomic_dec(&job->mappings[i]->obj->gpu_usecount);
> panfrost_gem_mapping_put(job->mappings[i]);
> }
> kvfree(job->mappings);
