[Mesa-dev] [PATCH 4/4] gbm: Add map/unmap functions

[Rob Herring]

On Fri, Apr 22, 2016 at 9:08 PM, Rob Herring <robh at kernel.org> wrote:
> On Fri, Apr 22, 2016 at 6:32 PM, Emil Velikov <emil.l.velikov at gmail.com> wrote:
>> Hi Rob,
>>
>> On 22 April 2016 at 16:50, Rob Herring <robh at kernel.org> wrote:
>>> This adds map and unmap functions to GBM utilizing the DRIimage extension
>>> mapImage/unmapImage functions or existing internal mapping for dumb
>>> buffers.
>> Ftr that this is quite sensitive and apart from the obvious breakage
>> (coming in a second) it will need some testing on a gnome-continuous
>> setup (iirc some used to hand out in #xorg-devel)
>>
>>> Unlike prior attempts, this version provides a region to map and
>>> usage flags for the mapping. The operation follows the same semantics as
>>> the gallium transfer_map() function.
>>>
>>> This was tested with GBM based gralloc on Android.
>>>
>>> This still creates a context, but I've moved it into gbm_create_device
>>> rather than in the map function. This should remove any need for reference
>>> counting and problems with memory leaks.
>>>
>>> Signed-off-by: Rob Herring <robh at kernel.org>
>
> [...]
>

>>> @@ -1004,6 +1058,10 @@ dri_device_create(int fd)
>>>     if (ret)
>>>        goto err_dri;
>>>
>>> +   if (dri->image->base.version >= 12)
>>> +      dri->context = dri->dri2->createNewContext(dri->screen, NULL,
>>> +                                                 NULL, NULL);
>>> +
>> Have you measured how much this costs us (cpu time and/or memory) ?
>
> No, will do.

On Android (x86_64 + virgl), it is 2ms and ~2MB (out of 20). A
standalone test with swrast is 4ms and ~4MB. I measured with
getrusage().

Rob