diff mbox

[1/2] dma-buf: keep only not signaled fence in reservation_object_add_shared_replace v2

Message ID 20171031084306.1986-1-christian.koenig@amd.com (mailing list archive)
State New, archived
Headers show

Commit Message

Christian König Oct. 31, 2017, 8:43 a.m. UTC
The amdgpu issue to also need signaled fences in the reservation objects
should be fixed by now.

Optimize the list by keeping only the not signaled yet fences around.

v2: temporary put the signaled fences at the end of the new container

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/dma-buf/reservation.c | 36 ++++++++++++++++++++++++++----------
 1 file changed, 26 insertions(+), 10 deletions(-)

Comments

Chunming Zhou Oct. 31, 2017, 8:51 a.m. UTC | #1
On 2017年10月31日 16:43, Christian König wrote:
> The amdgpu issue to also need signaled fences in the reservation objects
> should be fixed by now.
>
> Optimize the list by keeping only the not signaled yet fences around.
>
> v2: temporary put the signaled fences at the end of the new container
>
> Signed-off-by: Christian König <christian.koenig@amd.com>
> ---
>   drivers/dma-buf/reservation.c | 36 ++++++++++++++++++++++++++----------
>   1 file changed, 26 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c
> index b44d9d7db347..6fc794576997 100644
> --- a/drivers/dma-buf/reservation.c
> +++ b/drivers/dma-buf/reservation.c
> @@ -145,8 +145,8 @@ reservation_object_add_shared_replace(struct reservation_object *obj,
>   				      struct reservation_object_list *fobj,
>   				      struct dma_fence *fence)
>   {
> -	unsigned i;
>   	struct dma_fence *old_fence = NULL;
> +	unsigned i, j, k;
>   
>   	dma_fence_get(fence);
>   
> @@ -162,9 +162,7 @@ reservation_object_add_shared_replace(struct reservation_object *obj,
>   	 * references from the old struct are carried over to
>   	 * the new.
>   	 */
> -	fobj->shared_count = old->shared_count;
> -
> -	for (i = 0; i < old->shared_count; ++i) {
> +	for (i = 0, j = 0, k = fobj->shared_max; i < old->shared_count; ++i) {
>   		struct dma_fence *check;
>   
>   		check = rcu_dereference_protected(old->shared[i],
> @@ -172,10 +170,18 @@ reservation_object_add_shared_replace(struct reservation_object *obj,
>   
>   		if (!old_fence && check->context == fence->context) {
>   			old_fence = check;
> -			RCU_INIT_POINTER(fobj->shared[i], fence);
> -		} else
> -			RCU_INIT_POINTER(fobj->shared[i], check);
> +			RCU_INIT_POINTER(fobj->shared[j++], fence);
> +		} else if (!dma_fence_is_signaled(check)) {
> +			RCU_INIT_POINTER(fobj->shared[j++], check);
> +		} else {
> +			/*
> +			 * Temporary save the signaled fences at the end of the
> +			 * new container
> +			 */
> +			RCU_INIT_POINTER(fobj->shared[--k], check);
> +		}
>   	}
> +	fobj->shared_count = j;
>   	if (!old_fence) {
>   		RCU_INIT_POINTER(fobj->shared[fobj->shared_count], fence);
Seems you still don't address here, how do you sure 
fobj->shared[fobj->shared_count] is null? if not NULL, the old one will 
be leak.

Regards,
David Zhou
>   		fobj->shared_count++;
> @@ -192,10 +198,20 @@ reservation_object_add_shared_replace(struct reservation_object *obj,
>   	write_seqcount_end(&obj->seq);
>   	preempt_enable();
>   
> -	if (old)
> -		kfree_rcu(old, rcu);
> -
>   	dma_fence_put(old_fence);
> +
> +	if (!old)
> +		return;
> +
> +	/* Drop the references to the signaled fences */
> +	for (i = k; i < fobj->shared_max; ++i) {
> +		struct dma_fence *f;
> +
> +		f = rcu_dereference_protected(fobj->shared[i],
> +					      reservation_object_held(obj));
> +		dma_fence_put(f);
> +	}
> +	kfree_rcu(old, rcu);
>   }
>   
>   /**
Christian König Oct. 31, 2017, 8:55 a.m. UTC | #2
Am 31.10.2017 um 09:51 schrieb Chunming Zhou:
>
>
> On 2017年10月31日 16:43, Christian König wrote:
>> The amdgpu issue to also need signaled fences in the reservation objects
>> should be fixed by now.
>>
>> Optimize the list by keeping only the not signaled yet fences around.
>>
>> v2: temporary put the signaled fences at the end of the new container
>>
>> Signed-off-by: Christian König <christian.koenig@amd.com>
>> ---
>>   drivers/dma-buf/reservation.c | 36 
>> ++++++++++++++++++++++++++----------
>>   1 file changed, 26 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/dma-buf/reservation.c 
>> b/drivers/dma-buf/reservation.c
>> index b44d9d7db347..6fc794576997 100644
>> --- a/drivers/dma-buf/reservation.c
>> +++ b/drivers/dma-buf/reservation.c
>> @@ -145,8 +145,8 @@ reservation_object_add_shared_replace(struct 
>> reservation_object *obj,
>>                         struct reservation_object_list *fobj,
>>                         struct dma_fence *fence)
>>   {
>> -    unsigned i;
>>       struct dma_fence *old_fence = NULL;
>> +    unsigned i, j, k;
>>         dma_fence_get(fence);
>>   @@ -162,9 +162,7 @@ reservation_object_add_shared_replace(struct 
>> reservation_object *obj,
>>        * references from the old struct are carried over to
>>        * the new.
>>        */
>> -    fobj->shared_count = old->shared_count;
>> -
>> -    for (i = 0; i < old->shared_count; ++i) {
>> +    for (i = 0, j = 0, k = fobj->shared_max; i < old->shared_count; 
>> ++i) {
>>           struct dma_fence *check;
>>             check = rcu_dereference_protected(old->shared[i],
>> @@ -172,10 +170,18 @@ reservation_object_add_shared_replace(struct 
>> reservation_object *obj,
>>             if (!old_fence && check->context == fence->context) {
>>               old_fence = check;
>> -            RCU_INIT_POINTER(fobj->shared[i], fence);
>> -        } else
>> -            RCU_INIT_POINTER(fobj->shared[i], check);
>> +            RCU_INIT_POINTER(fobj->shared[j++], fence);
>> +        } else if (!dma_fence_is_signaled(check)) {
>> +            RCU_INIT_POINTER(fobj->shared[j++], check);
>> +        } else {
>> +            /*
>> +             * Temporary save the signaled fences at the end of the
>> +             * new container
>> +             */
>> +            RCU_INIT_POINTER(fobj->shared[--k], check);
>> +        }
>>       }
>> +    fobj->shared_count = j;
>>       if (!old_fence) {
>> RCU_INIT_POINTER(fobj->shared[fobj->shared_count], fence);
> Seems you still don't address here, how do you sure 
> fobj->shared[fobj->shared_count] is null? if not NULL, the old one 
> will be leak.

I've put them at the end of the container, see above "k = 
fobj->shared_max". Since shared_max >> shared_count (at least twice as 
large in this situation) we should be on the save side.

Regards,
Christian.

>
> Regards,
> David Zhou
>>           fobj->shared_count++;
>> @@ -192,10 +198,20 @@ reservation_object_add_shared_replace(struct 
>> reservation_object *obj,
>>       write_seqcount_end(&obj->seq);
>>       preempt_enable();
>>   -    if (old)
>> -        kfree_rcu(old, rcu);
>> -
>>       dma_fence_put(old_fence);
>> +
>> +    if (!old)
>> +        return;
>> +
>> +    /* Drop the references to the signaled fences */
>> +    for (i = k; i < fobj->shared_max; ++i) {
>> +        struct dma_fence *f;
>> +
>> +        f = rcu_dereference_protected(fobj->shared[i],
>> +                          reservation_object_held(obj));
>> +        dma_fence_put(f);
>> +    }
>> +    kfree_rcu(old, rcu);
>>   }
>>     /**
>
Chunming Zhou Oct. 31, 2017, 9:10 a.m. UTC | #3
On 2017年10月31日 16:55, Christian König wrote:
> Am 31.10.2017 um 09:51 schrieb Chunming Zhou:
>>
>>
>> On 2017年10月31日 16:43, Christian König wrote:
>>> The amdgpu issue to also need signaled fences in the reservation 
>>> objects
>>> should be fixed by now.
>>>
>>> Optimize the list by keeping only the not signaled yet fences around.
>>>
>>> v2: temporary put the signaled fences at the end of the new container
>>>
>>> Signed-off-by: Christian König <christian.koenig@amd.com>
>>> ---
>>>   drivers/dma-buf/reservation.c | 36 
>>> ++++++++++++++++++++++++++----------
>>>   1 file changed, 26 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/drivers/dma-buf/reservation.c 
>>> b/drivers/dma-buf/reservation.c
>>> index b44d9d7db347..6fc794576997 100644
>>> --- a/drivers/dma-buf/reservation.c
>>> +++ b/drivers/dma-buf/reservation.c
>>> @@ -145,8 +145,8 @@ reservation_object_add_shared_replace(struct 
>>> reservation_object *obj,
>>>                         struct reservation_object_list *fobj,
>>>                         struct dma_fence *fence)
>>>   {
>>> -    unsigned i;
>>>       struct dma_fence *old_fence = NULL;
>>> +    unsigned i, j, k;
>>>         dma_fence_get(fence);
>>>   @@ -162,9 +162,7 @@ reservation_object_add_shared_replace(struct 
>>> reservation_object *obj,
>>>        * references from the old struct are carried over to
>>>        * the new.
>>>        */
>>> -    fobj->shared_count = old->shared_count;
>>> -
>>> -    for (i = 0; i < old->shared_count; ++i) {
>>> +    for (i = 0, j = 0, k = fobj->shared_max; i < old->shared_count; 
>>> ++i) {
>>>           struct dma_fence *check;
>>>             check = rcu_dereference_protected(old->shared[i],
>>> @@ -172,10 +170,18 @@ reservation_object_add_shared_replace(struct 
>>> reservation_object *obj,
>>>             if (!old_fence && check->context == fence->context) {
>>>               old_fence = check;
>>> -            RCU_INIT_POINTER(fobj->shared[i], fence);
>>> -        } else
>>> -            RCU_INIT_POINTER(fobj->shared[i], check);
>>> +            RCU_INIT_POINTER(fobj->shared[j++], fence);
>>> +        } else if (!dma_fence_is_signaled(check)) {
>>> +            RCU_INIT_POINTER(fobj->shared[j++], check);
>>> +        } else {
>>> +            /*
>>> +             * Temporary save the signaled fences at the end of the
>>> +             * new container
>>> +             */
>>> +            RCU_INIT_POINTER(fobj->shared[--k], check);
>>> +        }
>>>       }
>>> +    fobj->shared_count = j;
>>>       if (!old_fence) {
>>> RCU_INIT_POINTER(fobj->shared[fobj->shared_count], fence);
>> Seems you still don't address here, how do you sure 
>> fobj->shared[fobj->shared_count] is null? if not NULL, the old one 
>> will be leak.
>
> I've put them at the end of the container, see above "k = 
> fobj->shared_max". Since shared_max >> shared_count (at least twice as 
> large in this situation) we should be on the save side.
Ah, oops, Reviewed-by: Chunming Zhou <david1.zhou@amd.com> for the series.

Thanks,
David Zhou
>
> Regards,
> Christian.
>
>>
>> Regards,
>> David Zhou
>>>           fobj->shared_count++;
>>> @@ -192,10 +198,20 @@ reservation_object_add_shared_replace(struct 
>>> reservation_object *obj,
>>>       write_seqcount_end(&obj->seq);
>>>       preempt_enable();
>>>   -    if (old)
>>> -        kfree_rcu(old, rcu);
>>> -
>>>       dma_fence_put(old_fence);
>>> +
>>> +    if (!old)
>>> +        return;
>>> +
>>> +    /* Drop the references to the signaled fences */
>>> +    for (i = k; i < fobj->shared_max; ++i) {
>>> +        struct dma_fence *f;
>>> +
>>> +        f = rcu_dereference_protected(fobj->shared[i],
>>> +                          reservation_object_held(obj));
>>> +        dma_fence_put(f);
>>> +    }
>>> +    kfree_rcu(old, rcu);
>>>   }
>>>     /**
>>
>
diff mbox

Patch

diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c
index b44d9d7db347..6fc794576997 100644
--- a/drivers/dma-buf/reservation.c
+++ b/drivers/dma-buf/reservation.c
@@ -145,8 +145,8 @@  reservation_object_add_shared_replace(struct reservation_object *obj,
 				      struct reservation_object_list *fobj,
 				      struct dma_fence *fence)
 {
-	unsigned i;
 	struct dma_fence *old_fence = NULL;
+	unsigned i, j, k;
 
 	dma_fence_get(fence);
 
@@ -162,9 +162,7 @@  reservation_object_add_shared_replace(struct reservation_object *obj,
 	 * references from the old struct are carried over to
 	 * the new.
 	 */
-	fobj->shared_count = old->shared_count;
-
-	for (i = 0; i < old->shared_count; ++i) {
+	for (i = 0, j = 0, k = fobj->shared_max; i < old->shared_count; ++i) {
 		struct dma_fence *check;
 
 		check = rcu_dereference_protected(old->shared[i],
@@ -172,10 +170,18 @@  reservation_object_add_shared_replace(struct reservation_object *obj,
 
 		if (!old_fence && check->context == fence->context) {
 			old_fence = check;
-			RCU_INIT_POINTER(fobj->shared[i], fence);
-		} else
-			RCU_INIT_POINTER(fobj->shared[i], check);
+			RCU_INIT_POINTER(fobj->shared[j++], fence);
+		} else if (!dma_fence_is_signaled(check)) {
+			RCU_INIT_POINTER(fobj->shared[j++], check);
+		} else {
+			/*
+			 * Temporary save the signaled fences at the end of the
+			 * new container
+			 */
+			RCU_INIT_POINTER(fobj->shared[--k], check);
+		}
 	}
+	fobj->shared_count = j;
 	if (!old_fence) {
 		RCU_INIT_POINTER(fobj->shared[fobj->shared_count], fence);
 		fobj->shared_count++;
@@ -192,10 +198,20 @@  reservation_object_add_shared_replace(struct reservation_object *obj,
 	write_seqcount_end(&obj->seq);
 	preempt_enable();
 
-	if (old)
-		kfree_rcu(old, rcu);
-
 	dma_fence_put(old_fence);
+
+	if (!old)
+		return;
+
+	/* Drop the references to the signaled fences */
+	for (i = k; i < fobj->shared_max; ++i) {
+		struct dma_fence *f;
+
+		f = rcu_dereference_protected(fobj->shared[i],
+					      reservation_object_held(obj));
+		dma_fence_put(f);
+	}
+	kfree_rcu(old, rcu);
 }
 
 /**