Re: [PATCH v4 2/5] dma-buf/sync_file: refactor fence storage in struct sync_file

[Sumit Semwal]

(Adding Greg KH)

Hi Greg,

On 19 July 2016 at 17:45, Sumit Semwal <sumit.semwal@xxxxxxxxxx> wrote:
> Hi Greg,
>
>
> On 12 July 2016 at 23:38, Gustavo Padovan <gustavo@xxxxxxxxxxx> wrote:
>> From: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxxxx>
>>
>> Create sync_file->fence to abstract the type of fence we are using for
>> each sync_file. If only one fence is present we use a normal struct fence
>> but if there is more fences to be added to the sync_file a fence_array
>> is created.
>>
>> This change cleans up sync_file a bit. We don't need to have sync_file_cb
>> array anymore. Instead, as we always have  one fence, only one fence
>> callback is registered per sync_file.
>>
> Since this is a simple change in sync_debug,c, may I request for your
> Ack so I could take it along with the other dma-buf patches?
>
Missed the fact that you weren't CCed; for this simple update to
sync_debug,c, may I request for your Ack so I can take it with dam-buf
patches?
>> v4: fixes checkpatch warnings
>>
>> v4: Comments from Chris Wilson
>>         - use sizeof(*fence) to reallocate array
>>         - fix typo in comments
>>         - protect num_fences sum against overflows
>>         - use array->base instead of casting the to struct fence
>>
>> v3: Comments from Chris Wilson and Christian KÃnig
>>         - struct sync_file lost status member in favor of fence_is_signaled()
>>         - drop use of fence_array_teardown()
>>         - use sizeof(*fence) to allocate only an array on fence pointers
>>
>> v2: Comments from Chris Wilson and Christian KÃnig
>>         - Not using fence_ops anymore
>>         - fence_is_array() was created to differentiate fence from fence_array
>>         - fence_array_teardown() is now exported and used under fence_is_array()
>>         - struct sync_file lost num_fences member
>>
>> Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
>> Cc: Christian KÃnig <christian.koenig@xxxxxxx>
>> Signed-off-by: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxxxx>
>> Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
>> Acked-by: Christian KÃnig <christian.koenig@xxxxxxx>
>> ---
>>  drivers/dma-buf/sync_file.c          | 169 +++++++++++++++++++++++------------
>>  drivers/staging/android/sync_debug.c |  12 ++-
>>  include/linux/sync_file.h            |  17 ++--
>>  3 files changed, 124 insertions(+), 74 deletions(-)
>>
> <snip>
>
>> diff --git a/drivers/staging/android/sync_debug.c b/drivers/staging/android/sync_debug.c
>> index 5f57499..e07958c 100644
>> --- a/drivers/staging/android/sync_debug.c
>> +++ b/drivers/staging/android/sync_debug.c
>> @@ -159,10 +159,16 @@ static void sync_print_sync_file(struct seq_file *s,
>>         int i;
>>
>>         seq_printf(s, "[%p] %s: %s\n", sync_file, sync_file->name,
>> -                  sync_status_str(atomic_read(&sync_file->status)));
>> +                  sync_status_str(!fence_is_signaled(sync_file->fence)));
>>
>> -       for (i = 0; i < sync_file->num_fences; ++i)
>> -               sync_print_fence(s, sync_file->cbs[i].fence, true);
>> +       if (fence_is_array(sync_file->fence)) {
>> +               struct fence_array *array = to_fence_array(sync_file->fence);
>> +
>> +               for (i = 0; i < array->num_fences; ++i)
>> +                       sync_print_fence(s, array->fences[i], true);
>> +       } else {
>> +               sync_print_fence(s, sync_file->fence, true);
>> +       }
>>  }
>>
>>  static int sync_debugfs_show(struct seq_file *s, void *unused)
>> diff --git a/include/linux/sync_file.h b/include/linux/sync_file.h
>> index c6ffe8b..2efc5ec 100644
>> --- a/include/linux/sync_file.h
>> +++ b/include/linux/sync_file.h
>> @@ -19,12 +19,7 @@
>>  #include <linux/list.h>
>>  #include <linux/spinlock.h>
>>  #include <linux/fence.h>
>> -
>> -struct sync_file_cb {
>> -       struct fence_cb cb;
>> -       struct fence *fence;
>> -       struct sync_file *sync_file;
>> -};
>> +#include <linux/fence-array.h>
>>
>>  /**
>>   * struct sync_file - sync file to export to the userspace
>> @@ -32,10 +27,9 @@ struct sync_file_cb {
>>   * @kref:              reference count on fence.
>>   * @name:              name of sync_file.  Useful for debugging
>>   * @sync_file_list:    membership in global file list
>> - * @num_fences:                number of sync_pts in the fence
>>   * @wq:                        wait queue for fence signaling
>> - * @status:            0: signaled, >0:active, <0: error
>> - * @cbs:               sync_pts callback information
>> + * @fence:             fence with the fences in the sync_file
>> + * @cb:                        fence callback information
>>   */
>>  struct sync_file {
>>         struct file             *file;
>> @@ -44,12 +38,11 @@ struct sync_file {
>>  #ifdef CONFIG_DEBUG_FS
>>         struct list_head        sync_file_list;
>>  #endif
>> -       int num_fences;
>>
>>         wait_queue_head_t       wq;
>> -       atomic_t                status;
>>
>> -       struct sync_file_cb     cbs[];
>> +       struct fence            *fence;
>> +       struct fence_cb cb;
>>  };
>>
>>  struct sync_file *sync_file_create(struct fence *fence);
>> --
>> 2.5.5
>>
>
> BR,
> ~Sumit.
>
> --
> Thanks and regards,
>
> Sumit Semwal
> Linaro Mobile Group - Kernel Team Lead
> Linaro.org â Open source software for ARM SoCs



-- 
Thanks and regards,

Sumit Semwal
Linaro Mobile Group - Kernel Team Lead
Linaro.org â Open source software for ARM SoCs