diff mbox series

[2/5] drm/exec: don't immediately add the prelocked obj

Message ID 20240703132602.4756-3-christian.koenig@amd.com (mailing list archive)
State New, archived
Headers show
Series [1/5] dma-buf/dma-resv: Introduce dma_resv_trylock_ctx() | expand

Commit Message

Christian König July 3, 2024, 1:25 p.m. UTC
Some contended objects might never be locked again in the case of eviction
handling for example.

Make sure that those doesn't show up in the list of locked objects until
they are explicitely mentioned.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/drm_exec.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

Comments

Thomas Hellström July 3, 2024, 3:51 p.m. UTC | #1
On Wed, 2024-07-03 at 15:25 +0200, Christian König wrote:
> Some contended objects might never be locked again in the case of
> eviction
> handling for example.
> 
> Make sure that those doesn't show up in the list of locked objects
> until
> they are explicitely mentioned.

Could you be a bit more specific in the commit message about in what
situations that is bad?

/Thomas



> 
> Signed-off-by: Christian König <christian.koenig@amd.com>
> ---
>  drivers/gpu/drm/drm_exec.c | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_exec.c b/drivers/gpu/drm/drm_exec.c
> index 2da094bdf8a4..220df336fbd9 100644
> --- a/drivers/gpu/drm/drm_exec.c
> +++ b/drivers/gpu/drm/drm_exec.c
> @@ -61,8 +61,11 @@ static void drm_exec_unlock_all(struct drm_exec
> *exec)
>  		drm_gem_object_put(obj);
>  	}
>  
> -	drm_gem_object_put(exec->prelocked);
> -	exec->prelocked = NULL;
> +	if (exec->prelocked) {
> +		dma_resv_unlock(exec->prelocked->resv);
> +		drm_gem_object_put(exec->prelocked);
> +		exec->prelocked = NULL;
> +	}
>  }
>  
>  /**
> @@ -179,16 +182,9 @@ static int drm_exec_lock_contended(struct
> drm_exec *exec)
>  		dma_resv_lock_slow(obj->resv, &exec->ticket);
>  	}
>  
> -	ret = drm_exec_obj_locked(exec, obj);
> -	if (unlikely(ret))
> -		goto error_unlock;
> -
>  	exec->prelocked = obj;
>  	return 0;
>  
> -error_unlock:
> -	dma_resv_unlock(obj->resv);
> -
>  error_dropref:
>  	drm_gem_object_put(obj);
>  	return ret;
> @@ -214,6 +210,10 @@ int drm_exec_lock_obj(struct drm_exec *exec,
> struct drm_gem_object *obj)
>  		return ret;
>  
>  	if (exec->prelocked == obj) {
> +		ret = drm_exec_obj_locked(exec, obj);
> +		if (unlikely(ret))
> +			return ret;
> +
>  		drm_gem_object_put(exec->prelocked);
>  		exec->prelocked = NULL;
>  		return 0;
Christian König July 5, 2024, 12:41 p.m. UTC | #2
Am 03.07.24 um 17:51 schrieb Thomas Hellström:
> On Wed, 2024-07-03 at 15:25 +0200, Christian König wrote:
>> Some contended objects might never be locked again in the case of
>> eviction
>> handling for example.
>>
>> Make sure that those doesn't show up in the list of locked objects
>> until
>> they are explicitely mentioned.
> Could you be a bit more specific in the commit message about in what
> situations that is bad?

The prelocked object is not necessarily expected to be in the list of 
locked objects.

I ran into issues because amdgpu tried to validate all locked objects 
and so tried to also validate the prelocked one (which was only locked 
for eviction).

That obviously didn't made much sense.

Regards,
Christian.

>
> /Thomas
>
>
>
>> Signed-off-by: Christian König <christian.koenig@amd.com>
>> ---
>>   drivers/gpu/drm/drm_exec.c | 18 +++++++++---------
>>   1 file changed, 9 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_exec.c b/drivers/gpu/drm/drm_exec.c
>> index 2da094bdf8a4..220df336fbd9 100644
>> --- a/drivers/gpu/drm/drm_exec.c
>> +++ b/drivers/gpu/drm/drm_exec.c
>> @@ -61,8 +61,11 @@ static void drm_exec_unlock_all(struct drm_exec
>> *exec)
>>   		drm_gem_object_put(obj);
>>   	}
>>   
>> -	drm_gem_object_put(exec->prelocked);
>> -	exec->prelocked = NULL;
>> +	if (exec->prelocked) {
>> +		dma_resv_unlock(exec->prelocked->resv);
>> +		drm_gem_object_put(exec->prelocked);
>> +		exec->prelocked = NULL;
>> +	}
>>   }
>>   
>>   /**
>> @@ -179,16 +182,9 @@ static int drm_exec_lock_contended(struct
>> drm_exec *exec)
>>   		dma_resv_lock_slow(obj->resv, &exec->ticket);
>>   	}
>>   
>> -	ret = drm_exec_obj_locked(exec, obj);
>> -	if (unlikely(ret))
>> -		goto error_unlock;
>> -
>>   	exec->prelocked = obj;
>>   	return 0;
>>   
>> -error_unlock:
>> -	dma_resv_unlock(obj->resv);
>> -
>>   error_dropref:
>>   	drm_gem_object_put(obj);
>>   	return ret;
>> @@ -214,6 +210,10 @@ int drm_exec_lock_obj(struct drm_exec *exec,
>> struct drm_gem_object *obj)
>>   		return ret;
>>   
>>   	if (exec->prelocked == obj) {
>> +		ret = drm_exec_obj_locked(exec, obj);
>> +		if (unlikely(ret))
>> +			return ret;
>> +
>>   		drm_gem_object_put(exec->prelocked);
>>   		exec->prelocked = NULL;
>>   		return 0;
Thomas Hellström July 5, 2024, 1:33 p.m. UTC | #3
On Fri, 2024-07-05 at 14:41 +0200, Christian König wrote:
> Am 03.07.24 um 17:51 schrieb Thomas Hellström:
> > On Wed, 2024-07-03 at 15:25 +0200, Christian König wrote:
> > > Some contended objects might never be locked again in the case of
> > > eviction
> > > handling for example.
> > > 
> > > Make sure that those doesn't show up in the list of locked
> > > objects
> > > until
> > > they are explicitely mentioned.
> > Could you be a bit more specific in the commit message about in
> > what
> > situations that is bad?
> 
> The prelocked object is not necessarily expected to be in the list of
> locked objects.
> 
> I ran into issues because amdgpu tried to validate all locked objects
> and so tried to also validate the prelocked one (which was only
> locked 
> for eviction).
> 
> That obviously didn't made much sense.

Indeed. Could you add a similar description to the commit message?

/Thomas



> 
> Regards,
> Christian.
> 
> > 
> > /Thomas
> > 
> > 
> > 
> > > Signed-off-by: Christian König <christian.koenig@amd.com>
> > > ---
> > >   drivers/gpu/drm/drm_exec.c | 18 +++++++++---------
> > >   1 file changed, 9 insertions(+), 9 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/drm_exec.c
> > > b/drivers/gpu/drm/drm_exec.c
> > > index 2da094bdf8a4..220df336fbd9 100644
> > > --- a/drivers/gpu/drm/drm_exec.c
> > > +++ b/drivers/gpu/drm/drm_exec.c
> > > @@ -61,8 +61,11 @@ static void drm_exec_unlock_all(struct
> > > drm_exec
> > > *exec)
> > >   		drm_gem_object_put(obj);
> > >   	}
> > >   
> > > -	drm_gem_object_put(exec->prelocked);
> > > -	exec->prelocked = NULL;
> > > +	if (exec->prelocked) {
> > > +		dma_resv_unlock(exec->prelocked->resv);
> > > +		drm_gem_object_put(exec->prelocked);
> > > +		exec->prelocked = NULL;
> > > +	}
> > >   }
> > >   
> > >   /**
> > > @@ -179,16 +182,9 @@ static int drm_exec_lock_contended(struct
> > > drm_exec *exec)
> > >   		dma_resv_lock_slow(obj->resv, &exec->ticket);
> > >   	}
> > >   
> > > -	ret = drm_exec_obj_locked(exec, obj);
> > > -	if (unlikely(ret))
> > > -		goto error_unlock;
> > > -
> > >   	exec->prelocked = obj;
> > >   	return 0;
> > >   
> > > -error_unlock:
> > > -	dma_resv_unlock(obj->resv);
> > > -
> > >   error_dropref:
> > >   	drm_gem_object_put(obj);
> > >   	return ret;
> > > @@ -214,6 +210,10 @@ int drm_exec_lock_obj(struct drm_exec *exec,
> > > struct drm_gem_object *obj)
> > >   		return ret;
> > >   
> > >   	if (exec->prelocked == obj) {
> > > +		ret = drm_exec_obj_locked(exec, obj);
> > > +		if (unlikely(ret))
> > > +			return ret;
> > > +
> > >   		drm_gem_object_put(exec->prelocked);
> > >   		exec->prelocked = NULL;
> > >   		return 0;
>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_exec.c b/drivers/gpu/drm/drm_exec.c
index 2da094bdf8a4..220df336fbd9 100644
--- a/drivers/gpu/drm/drm_exec.c
+++ b/drivers/gpu/drm/drm_exec.c
@@ -61,8 +61,11 @@  static void drm_exec_unlock_all(struct drm_exec *exec)
 		drm_gem_object_put(obj);
 	}
 
-	drm_gem_object_put(exec->prelocked);
-	exec->prelocked = NULL;
+	if (exec->prelocked) {
+		dma_resv_unlock(exec->prelocked->resv);
+		drm_gem_object_put(exec->prelocked);
+		exec->prelocked = NULL;
+	}
 }
 
 /**
@@ -179,16 +182,9 @@  static int drm_exec_lock_contended(struct drm_exec *exec)
 		dma_resv_lock_slow(obj->resv, &exec->ticket);
 	}
 
-	ret = drm_exec_obj_locked(exec, obj);
-	if (unlikely(ret))
-		goto error_unlock;
-
 	exec->prelocked = obj;
 	return 0;
 
-error_unlock:
-	dma_resv_unlock(obj->resv);
-
 error_dropref:
 	drm_gem_object_put(obj);
 	return ret;
@@ -214,6 +210,10 @@  int drm_exec_lock_obj(struct drm_exec *exec, struct drm_gem_object *obj)
 		return ret;
 
 	if (exec->prelocked == obj) {
+		ret = drm_exec_obj_locked(exec, obj);
+		if (unlikely(ret))
+			return ret;
+
 		drm_gem_object_put(exec->prelocked);
 		exec->prelocked = NULL;
 		return 0;