Re: [Freedreno] [PATCH 04/14] drm/msm: Add priv->mm_lock to protect active/inactive lists
On Sun, Oct 04, 2020 at 12:21:36PM -0700, Rob Clark wrote:
> From: Rob Clark
>
> Rather than relying on the big dev->struct_mutex hammer, introduce a
> more specific lock for protecting the bo lists.
Most excellent.
Reviewed-by: Jordan Crouse
> Signed-off-by: Rob Clark
> ---
> drivers/gpu/drm/msm/msm_debugfs.c | 7 +++
> drivers/gpu/drm/msm/msm_drv.c | 1 +
> drivers/gpu/drm/msm/msm_drv.h | 13 +++-
> drivers/gpu/drm/msm/msm_gem.c | 28 +++---
> drivers/gpu/drm/msm/msm_gem_shrinker.c | 12 +++
> drivers/gpu/drm/msm/msm_gpu.h | 5 -
> 6 files changed, 52 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_debugfs.c
> b/drivers/gpu/drm/msm/msm_debugfs.c
> index ee2e270f464c..64afbed89821 100644
> --- a/drivers/gpu/drm/msm/msm_debugfs.c
> +++ b/drivers/gpu/drm/msm/msm_debugfs.c
> @@ -112,6 +112,11 @@ static int msm_gem_show(struct drm_device *dev, struct
> seq_file *m)
> {
> struct msm_drm_private *priv = dev->dev_private;
> struct msm_gpu *gpu = priv->gpu;
> + int ret;
> +
> + ret = mutex_lock_interruptible(&priv->mm_lock);
> + if (ret)
> + return ret;
>
> if (gpu) {
> seq_printf(m, "Active Objects (%s):\n", gpu->name);
> @@ -121,6 +126,8 @@ static int msm_gem_show(struct drm_device *dev, struct
> seq_file *m)
> seq_printf(m, "Inactive Objects:\n");
> msm_gem_describe_objects(&priv->inactive_list, m);
>
> + mutex_unlock(&priv->mm_lock);
> +
> return 0;
> }
>
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 49685571dc0e..dc6efc089285 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -441,6 +441,7 @@ static int msm_drm_init(struct device *dev, struct
> drm_driver *drv)
> init_llist_head(&priv->free_list);
>
> INIT_LIST_HEAD(&priv->inactive_list);
> + mutex_init(&priv->mm_lock);
>
> drm_mode_config_init(ddev);
>
> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> index b9dd8f8f4887..50978e5db376 100644
> --- a/drivers/gpu/drm/msm/msm_drv.h
> +++ b/drivers/gpu/drm/msm/msm_drv.h
> @@ -174,8 +174,19 @@ struct msm_drm_private {
> struct msm_rd_state *hangrd; /* debugfs to dump hanging submits */
> struct msm_perf_state *perf;
>
> - /* list of GEM objects: */
> + /*
> + * List of inactive GEM objects. Every bo is either in the
> inactive_list
> + * or gpu->active_list (for the gpu it is active on[1])
> + *
> + * These lists are protected by mm_lock. If struct_mutex is involved,
> it
> + * should be aquired prior to mm_lock. One should *not* hold mm_lock in
> + * get_pages()/vmap()/etc paths, as they can trigger the shrinker.
> + *
> + * [1] if someone ever added support for the old 2d cores, there could
> be
> + * more than one gpu object
> + */
> struct list_head inactive_list;
> + struct mutex mm_lock;
>
> /* worker for delayed free of objects: */
> struct work_struct free_work;
> diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
> index a870b3ad129d..b04ed8b52f9d 100644
> --- a/drivers/gpu/drm/msm/msm_gem.c
> +++ b/drivers/gpu/drm/msm/msm_gem.c
> @@ -746,13 +746,17 @@ int msm_gem_sync_object(struct drm_gem_object *obj,
> void msm_gem_active_get(struct drm_gem_object *obj, struct msm_gpu *gpu)
> {
> struct msm_gem_object *msm_obj = to_msm_bo(obj);
> - WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
> + struct msm_drm_private *priv = obj->dev->dev_private;
> +
> + might_sleep();
> WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED);
>
> if (!atomic_fetch_inc(&msm_obj->active_count)) {
> + mutex_lock(&priv->mm_lock);
> msm_obj->gpu = gpu;
> list_del_init(&msm_obj->mm_list);
> list_add_tail(&msm_obj->mm_list, &gpu->active_list);
> + mutex_unlock(&priv->mm_lock);
> }
> }
>
> @@ -761,12 +765,14 @@ void msm_gem_active_put(struct drm_gem_object *obj)
> struct msm_gem_object *msm_obj = to_msm_bo(obj);
> struct msm_drm_private *priv = obj->dev->dev_private;
>
> - WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
> + might_sleep();
>
> if (!atomic_dec_return(&msm_obj->active_count)) {
> + mutex_lock(&priv->mm_lock);
> msm_obj->gpu = NULL;
> list_del_init(&msm_obj->mm_list);
> list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
> + mutex_unlock(&priv->mm_lock);
> }
> }
>
> @@ -921,13 +927,16 @@ static void free_object(struct msm_gem_object *msm_obj)
> {
> struct drm_gem_object *obj = &msm_obj->base;
> struct drm_device *dev = obj->dev;
> + struct msm_drm_private *priv = dev->dev_private;
>
> WARN_ON(!mutex_is_locked(&dev->struct
Re: [PATCH 04/14] drm/msm: Add priv->mm_lock to protect active/inactive lists
On Sun, Oct 4, 2020 at 3:15 PM Daniel Vetter wrote:
>
> On Sun, Oct 4, 2020 at 9:21 PM Rob Clark wrote:
> >
> > From: Rob Clark
> >
> > Rather than relying on the big dev->struct_mutex hammer, introduce a
> > more specific lock for protecting the bo lists.
> >
> > Signed-off-by: Rob Clark
> > ---
> > drivers/gpu/drm/msm/msm_debugfs.c | 7 +++
> > drivers/gpu/drm/msm/msm_drv.c | 1 +
> > drivers/gpu/drm/msm/msm_drv.h | 13 +++-
> > drivers/gpu/drm/msm/msm_gem.c | 28 +++---
> > drivers/gpu/drm/msm/msm_gem_shrinker.c | 12 +++
> > drivers/gpu/drm/msm/msm_gpu.h | 5 -
> > 6 files changed, 52 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_debugfs.c
> > b/drivers/gpu/drm/msm/msm_debugfs.c
> > index ee2e270f464c..64afbed89821 100644
> > --- a/drivers/gpu/drm/msm/msm_debugfs.c
> > +++ b/drivers/gpu/drm/msm/msm_debugfs.c
> > @@ -112,6 +112,11 @@ static int msm_gem_show(struct drm_device *dev, struct
> > seq_file *m)
> > {
> > struct msm_drm_private *priv = dev->dev_private;
> > struct msm_gpu *gpu = priv->gpu;
> > + int ret;
> > +
> > + ret = mutex_lock_interruptible(&priv->mm_lock);
> > + if (ret)
> > + return ret;
> >
> > if (gpu) {
> > seq_printf(m, "Active Objects (%s):\n", gpu->name);
> > @@ -121,6 +126,8 @@ static int msm_gem_show(struct drm_device *dev, struct
> > seq_file *m)
> > seq_printf(m, "Inactive Objects:\n");
> > msm_gem_describe_objects(&priv->inactive_list, m);
> >
> > + mutex_unlock(&priv->mm_lock);
> > +
> > return 0;
> > }
> >
> > diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> > index 49685571dc0e..dc6efc089285 100644
> > --- a/drivers/gpu/drm/msm/msm_drv.c
> > +++ b/drivers/gpu/drm/msm/msm_drv.c
> > @@ -441,6 +441,7 @@ static int msm_drm_init(struct device *dev, struct
> > drm_driver *drv)
> > init_llist_head(&priv->free_list);
> >
> > INIT_LIST_HEAD(&priv->inactive_list);
> > + mutex_init(&priv->mm_lock);
>
> I highly recommend you drop a
>
> fs_reclaim_acquire(GFP_KERNEL);
> might_lock(&priv->mm_lock);
> fs_reclaim_release(GFP_KERNEL);
>
> in here to teach lockdep about your ordering against the shrinker.
> Gives you full testing every boot, even if your shrinker never gets
> called.
Good idea..
(tbf, I have tested this with android+lockdep which pretty is great
shrinker exercise.. but immediate notification of future problems is a
good plan)
BR,
-R
Re: [PATCH 04/14] drm/msm: Add priv->mm_lock to protect active/inactive lists
On Sun, Oct 4, 2020 at 9:21 PM Rob Clark wrote:
>
> From: Rob Clark
>
> Rather than relying on the big dev->struct_mutex hammer, introduce a
> more specific lock for protecting the bo lists.
>
> Signed-off-by: Rob Clark
> ---
> drivers/gpu/drm/msm/msm_debugfs.c | 7 +++
> drivers/gpu/drm/msm/msm_drv.c | 1 +
> drivers/gpu/drm/msm/msm_drv.h | 13 +++-
> drivers/gpu/drm/msm/msm_gem.c | 28 +++---
> drivers/gpu/drm/msm/msm_gem_shrinker.c | 12 +++
> drivers/gpu/drm/msm/msm_gpu.h | 5 -
> 6 files changed, 52 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_debugfs.c
> b/drivers/gpu/drm/msm/msm_debugfs.c
> index ee2e270f464c..64afbed89821 100644
> --- a/drivers/gpu/drm/msm/msm_debugfs.c
> +++ b/drivers/gpu/drm/msm/msm_debugfs.c
> @@ -112,6 +112,11 @@ static int msm_gem_show(struct drm_device *dev, struct
> seq_file *m)
> {
> struct msm_drm_private *priv = dev->dev_private;
> struct msm_gpu *gpu = priv->gpu;
> + int ret;
> +
> + ret = mutex_lock_interruptible(&priv->mm_lock);
> + if (ret)
> + return ret;
>
> if (gpu) {
> seq_printf(m, "Active Objects (%s):\n", gpu->name);
> @@ -121,6 +126,8 @@ static int msm_gem_show(struct drm_device *dev, struct
> seq_file *m)
> seq_printf(m, "Inactive Objects:\n");
> msm_gem_describe_objects(&priv->inactive_list, m);
>
> + mutex_unlock(&priv->mm_lock);
> +
> return 0;
> }
>
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 49685571dc0e..dc6efc089285 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -441,6 +441,7 @@ static int msm_drm_init(struct device *dev, struct
> drm_driver *drv)
> init_llist_head(&priv->free_list);
>
> INIT_LIST_HEAD(&priv->inactive_list);
> + mutex_init(&priv->mm_lock);
I highly recommend you drop a
fs_reclaim_acquire(GFP_KERNEL);
might_lock(&priv->mm_lock);
fs_reclaim_release(GFP_KERNEL);
in here to teach lockdep about your ordering against the shrinker.
Gives you full testing every boot, even if your shrinker never gets
called.
-Daniel
>
> drm_mode_config_init(ddev);
>
> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> index b9dd8f8f4887..50978e5db376 100644
> --- a/drivers/gpu/drm/msm/msm_drv.h
> +++ b/drivers/gpu/drm/msm/msm_drv.h
> @@ -174,8 +174,19 @@ struct msm_drm_private {
> struct msm_rd_state *hangrd; /* debugfs to dump hanging submits */
> struct msm_perf_state *perf;
>
> - /* list of GEM objects: */
> + /*
> +* List of inactive GEM objects. Every bo is either in the
> inactive_list
> +* or gpu->active_list (for the gpu it is active on[1])
> +*
> +* These lists are protected by mm_lock. If struct_mutex is
> involved, it
> +* should be aquired prior to mm_lock. One should *not* hold mm_lock
> in
> +* get_pages()/vmap()/etc paths, as they can trigger the shrinker.
> +*
> +* [1] if someone ever added support for the old 2d cores, there
> could be
> +* more than one gpu object
> +*/
> struct list_head inactive_list;
> + struct mutex mm_lock;
>
> /* worker for delayed free of objects: */
> struct work_struct free_work;
> diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
> index a870b3ad129d..b04ed8b52f9d 100644
> --- a/drivers/gpu/drm/msm/msm_gem.c
> +++ b/drivers/gpu/drm/msm/msm_gem.c
> @@ -746,13 +746,17 @@ int msm_gem_sync_object(struct drm_gem_object *obj,
> void msm_gem_active_get(struct drm_gem_object *obj, struct msm_gpu *gpu)
> {
> struct msm_gem_object *msm_obj = to_msm_bo(obj);
> - WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
> + struct msm_drm_private *priv = obj->dev->dev_private;
> +
> + might_sleep();
> WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED);
>
> if (!atomic_fetch_inc(&msm_obj->active_count)) {
> + mutex_lock(&priv->mm_lock);
> msm_obj->gpu = gpu;
> list_del_init(&msm_obj->mm_list);
> list_add_tail(&msm_obj->mm_list, &gpu->active_list);
> + mutex_unlock(&priv->mm_lock);
> }
> }
>
> @@ -761,12 +765,14 @@ void msm_gem_active_put(struct drm_gem_object *obj)
> struct msm_gem_object *msm_obj = to_msm_bo(obj);
> struct msm_drm_private *priv = obj->dev->dev_private;
>
> - WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
> + might_sleep();
>
> if (!atomic_dec_return(&msm_obj->active_count)) {
> + mutex_lock(&priv->mm_lock);
> msm_obj->gpu = NULL;
> list_del_init(&msm_obj->mm_list);
> list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
> + mutex_unlock(&priv->mm_
[PATCH 04/14] drm/msm: Add priv->mm_lock to protect active/inactive lists
From: Rob Clark
Rather than relying on the big dev->struct_mutex hammer, introduce a
more specific lock for protecting the bo lists.
Signed-off-by: Rob Clark
---
drivers/gpu/drm/msm/msm_debugfs.c | 7 +++
drivers/gpu/drm/msm/msm_drv.c | 1 +
drivers/gpu/drm/msm/msm_drv.h | 13 +++-
drivers/gpu/drm/msm/msm_gem.c | 28 +++---
drivers/gpu/drm/msm/msm_gem_shrinker.c | 12 +++
drivers/gpu/drm/msm/msm_gpu.h | 5 -
6 files changed, 52 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_debugfs.c
b/drivers/gpu/drm/msm/msm_debugfs.c
index ee2e270f464c..64afbed89821 100644
--- a/drivers/gpu/drm/msm/msm_debugfs.c
+++ b/drivers/gpu/drm/msm/msm_debugfs.c
@@ -112,6 +112,11 @@ static int msm_gem_show(struct drm_device *dev, struct
seq_file *m)
{
struct msm_drm_private *priv = dev->dev_private;
struct msm_gpu *gpu = priv->gpu;
+ int ret;
+
+ ret = mutex_lock_interruptible(&priv->mm_lock);
+ if (ret)
+ return ret;
if (gpu) {
seq_printf(m, "Active Objects (%s):\n", gpu->name);
@@ -121,6 +126,8 @@ static int msm_gem_show(struct drm_device *dev, struct
seq_file *m)
seq_printf(m, "Inactive Objects:\n");
msm_gem_describe_objects(&priv->inactive_list, m);
+ mutex_unlock(&priv->mm_lock);
+
return 0;
}
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 49685571dc0e..dc6efc089285 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -441,6 +441,7 @@ static int msm_drm_init(struct device *dev, struct
drm_driver *drv)
init_llist_head(&priv->free_list);
INIT_LIST_HEAD(&priv->inactive_list);
+ mutex_init(&priv->mm_lock);
drm_mode_config_init(ddev);
diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index b9dd8f8f4887..50978e5db376 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -174,8 +174,19 @@ struct msm_drm_private {
struct msm_rd_state *hangrd; /* debugfs to dump hanging submits */
struct msm_perf_state *perf;
- /* list of GEM objects: */
+ /*
+* List of inactive GEM objects. Every bo is either in the
inactive_list
+* or gpu->active_list (for the gpu it is active on[1])
+*
+* These lists are protected by mm_lock. If struct_mutex is involved,
it
+* should be aquired prior to mm_lock. One should *not* hold mm_lock in
+* get_pages()/vmap()/etc paths, as they can trigger the shrinker.
+*
+* [1] if someone ever added support for the old 2d cores, there could
be
+* more than one gpu object
+*/
struct list_head inactive_list;
+ struct mutex mm_lock;
/* worker for delayed free of objects: */
struct work_struct free_work;
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index a870b3ad129d..b04ed8b52f9d 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -746,13 +746,17 @@ int msm_gem_sync_object(struct drm_gem_object *obj,
void msm_gem_active_get(struct drm_gem_object *obj, struct msm_gpu *gpu)
{
struct msm_gem_object *msm_obj = to_msm_bo(obj);
- WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+ struct msm_drm_private *priv = obj->dev->dev_private;
+
+ might_sleep();
WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED);
if (!atomic_fetch_inc(&msm_obj->active_count)) {
+ mutex_lock(&priv->mm_lock);
msm_obj->gpu = gpu;
list_del_init(&msm_obj->mm_list);
list_add_tail(&msm_obj->mm_list, &gpu->active_list);
+ mutex_unlock(&priv->mm_lock);
}
}
@@ -761,12 +765,14 @@ void msm_gem_active_put(struct drm_gem_object *obj)
struct msm_gem_object *msm_obj = to_msm_bo(obj);
struct msm_drm_private *priv = obj->dev->dev_private;
- WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+ might_sleep();
if (!atomic_dec_return(&msm_obj->active_count)) {
+ mutex_lock(&priv->mm_lock);
msm_obj->gpu = NULL;
list_del_init(&msm_obj->mm_list);
list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
+ mutex_unlock(&priv->mm_lock);
}
}
@@ -921,13 +927,16 @@ static void free_object(struct msm_gem_object *msm_obj)
{
struct drm_gem_object *obj = &msm_obj->base;
struct drm_device *dev = obj->dev;
+ struct msm_drm_private *priv = dev->dev_private;
WARN_ON(!mutex_is_locked(&dev->struct_mutex));
/* object should not be on active list: */
WARN_ON(is_active(msm_obj));
+ mutex_lock(&priv->mm_lock);
list_del(&msm_obj->mm_list);
+ mutex_unlock(&priv->mm_lock);
mutex_lock(&msm_ob
