On 08/08/2019 17:48, Chunming Zhou
wrote:
> 在 2019/8/8 22:34, Lionel Landwerlin 写道:
>> On 08/08/2019 17:16, Chunming Zhou wrote:
>>> 在 2019/8/8 22:01, Lionel Landwerlin 写道:
>>>> On 08/08/2019 16:42, Chunming Zhou wrote:
>>>>> No, I just see your comment "The next
vkQueueSubmit()
>>>>> waiting on a the syncobj will read
the sideband payload and wait for a
>>>>> fence chain element with a seqno
superior or equal to the sideband
>>>>> payload value to be added into the
fence chain and use that fence to
>>>>> trigger the submission on the kernel
driver. ".
>>>> That was meant to say wait on the chain
fence to reach the sideband
>>>> payload value.
>>>>
>>>> It a bit confusing but I can't see any
other way to word it.
>>>>
>>>>
>>>>> In that, you mentioned wait for
sideband.
>>>>> So I want to know we how to use that,
maybe I miss something in
>>>>> previous
>>>>> discussing thread.
>>>> In QueueSubmit(), we start by reading the
sideband payloads :
>>>>
https://gitlab.freedesktop.org/llandwerlin/mesa/blob/review/anv-timeline_semaphore_prep/src/intel/vulkan/anv_queue.c#L655
>>>>
>>>>
>>>> Then build everything for the submission
and hand it over to the
>>>> submission thread.
>>>>
>>>> Instead of the just waiting on the
timeline semaphore values, we also
>>>> wait on the binary semaphore sideband
payload values.
>>> Waiting on timeline values is when finding
fence in kernel.
>>
>> Hmm aren't you waiting in a thread in userspace?
> Yes, For timeline case, we can use
waitForSyncobj()..., At begin of
> QueueThread, I let it wait in cs_ioctl when
drm_syncobj_find_fence.
>
> But I still didn't get how to wait on sideband for
binary Syncobj.
>
> Ah, I see, you will compare it in your QueueThread,
if sideband value is
> >= expected, then do submission, otherwise, loop
QueueThread, right?
Just treat binary semaphores as timelines and
waitForSyncobj on the
sideband payload value.
It should make the submission thread any busier than
currently.
-Lionel
>
> That sounds the QueueThread will be always busy.
>
> -David
>
>
>>
>>> But I don't see how to wait/block in kernel
when finding fence for
>>> binary sideband payload values.
>>
>> Essentially our driver now handles timelines
& binary semaphore using
>> dma-fence-chain in both cases.
>
>
>> Only with timelines we take the values submitted
by the vulkan
>> application.
>
>> The binary semaphore auto increment on
vkQueueSubmit() and that is
>> managed by the userspace driver.
>>
>>
>> -Lionel
>>
>>
>>>
>>> -David
>>>
>>>> Finally before exiting the QueueSubmit()
call, we bump the sideband
>>>> payloads of all the binary semaphores
have have been signaled :
>>>>
https://gitlab.freedesktop.org/llandwerlin/mesa/blob/review/anv-timeline_semaphore_prep/src/intel/vulkan/anv_queue.c#L806
>>>>
>>>>
>>>>
>>>> Whoever calls QueueSubmit() after that
will pickup the new sideband
>>>> payload values to wait on.
>>>>
>>>>
>>>> -Lionel
>>>>
>>>>
>>>>
>>>>> -DAvid
>>>>>
>>>>>
>>>>> 在 2019/8/8 21:38, Lionel Landwerlin
写道:
>>>>>> Interesting question :)
>>>>>>
>>>>>> I didn't see any usecase for
that.
>>>>>> This sideband payload value is
used for a wait so waiting on the wait
>>>>>> value for another wait is bit
meta :)
>>>>>>
>>>>>> Do you have a use case for that?
>>>>>>
>>>>>> -Lionel
>>>>>>
>>>>>> On 08/08/2019 16:23, Chunming
Zhou wrote:
>>>>>>> The propursal is fine with
me.
>>>>>>>
>>>>>>> one question:
>>>>>>>
>>>>>>> how to wait sideband payload?
Following patch will show that?
>>>>>>>
>>>>>>> -David
>>>>>>>
>>>>>>> 在 2019/8/8 21:14, Lionel
Landwerlin 写道:
>>>>>>>> The Vulkan timeline
semaphores allow signaling to happen on the
>>>>>>>> point
>>>>>>>> of the timeline without
all of the its dependencies to be created.
>>>>>>>>
>>>>>>>> The current 2
implementations (AMD/Intel) of the Vulkan spec on
>>>>>>>> top of
>>>>>>>> the Linux kernel are
using a thread to wait on the dependencies
>>>>>>>> of a
>>>>>>>> given point to
materialize and delay actual submission to the
>>>>>>>> kernel
>>>>>>>> driver until the wait
completes.
>>>>>>>>
>>>>>>>> If a binary semaphore is
submitted for signaling along the side
>>>>>>>> of a
>>>>>>>> timeline semaphore
waiting for completion that means that the drm
>>>>>>>> syncobj associated with
that binary semaphore will not have a DMA
>>>>>>>> fence associated with it
by the time vkQueueSubmit() returns. This
>>>>>>>> and
>>>>>>>> the fact that a binary
semaphore can be signaled and unsignaled as
>>>>>>>> before its DMA fences
materialize mean that we cannot just rely on
>>>>>>>> the
>>>>>>>> fence within the syncobj
but we also need a sideband payload
>>>>>>>> verifying
>>>>>>>> that the fence in the
syncobj matches the last submission from the
>>>>>>>> Vulkan API point of view.
>>>>>>>>
>>>>>>>> This change adds a
sideband payload that is incremented with
>>>>>>>> signaled
>>>>>>>> syncobj when
vkQueueSubmit() is called. The next vkQueueSubmit()
>>>>>>>> waiting on a the syncobj
will read the sideband payload and wait
>>>>>>>> for a
>>>>>>>> fence chain element with
a seqno superior or equal to the sideband
>>>>>>>> payload value to be added
into the fence chain and use that
>>>>>>>> fence to
>>>>>>>> trigger the submission on
the kernel driver.
>>>>>>>>
>>>>>>>> v2: Use a separate ioctl
to get/set the sideband value (Christian)
>>>>>>>>
>>>>>>>> v3: Use 2 ioctls for
get/set (Christian)
>>>>>>>>
>>>>>>>> Signed-off-by: Lionel
Landwerlin
<lionel.g.landwerlin@xxxxxxxxx>
>>>>>>>> Cc: Christian Koenig
<Christian.Koenig@xxxxxxx>
>>>>>>>> Cc: Jason Ekstrand
<jason@xxxxxxxxxxxxxx>
>>>>>>>> Cc: David(ChunMing) Zhou
<David1.Zhou@xxxxxxx>
>>>>>>>> ---
>>>>>>>>
drivers/gpu/drm/drm_internal.h | 4 ++
>>>>>>>>
drivers/gpu/drm/drm_ioctl.c | 5 +++
>>>>>>>>
drivers/gpu/drm/drm_syncobj.c | 79
>>>>>>>>
+++++++++++++++++++++++++++++++++-
>>>>>>>>
include/drm/drm_syncobj.h | 9 ++++
>>>>>>>>
include/uapi/drm/drm.h | 2 +
>>>>>>>> 5 files changed, 98
insertions(+), 1 deletion(-)
>>>>>>>>
>>>>>>>> diff --git
a/drivers/gpu/drm/drm_internal.h
>>>>>>>>
b/drivers/gpu/drm/drm_internal.h
>>>>>>>> index
51a2055c8f18..0c9736199df0 100644
>>>>>>>> ---
a/drivers/gpu/drm/drm_internal.h
>>>>>>>> +++
b/drivers/gpu/drm/drm_internal.h
>>>>>>>> @@ -208,6 +208,10 @@ int
drm_syncobj_timeline_signal_ioctl(struct
>>>>>>>> drm_device *dev, void
*data,
>>>>>>>>
struct drm_file *file_private);
>>>>>>>> int
drm_syncobj_query_ioctl(struct drm_device *dev, void
>>>>>>>> *data,
>>>>>>>>
struct drm_file *file_private);
>>>>>>>> +int
drm_syncobj_get_sideband_ioctl(struct drm_device *dev,
void
>>>>>>>> *data,
>>>>>>>> +
struct drm_file *file_private);
>>>>>>>> +int
drm_syncobj_set_sideband_ioctl(struct drm_device *dev,
void
>>>>>>>> *data,
>>>>>>>> +
struct drm_file *file_private);
>>>>>>>> /*
drm_framebuffer.c */
>>>>>>>> void
drm_framebuffer_print_info(struct drm_printer *p,
>>>>>>>> unsigned
>>>>>>>> int indent,
>>>>>>>> diff --git
a/drivers/gpu/drm/drm_ioctl.c
>>>>>>>>
b/drivers/gpu/drm/drm_ioctl.c
>>>>>>>> index
f675a3bb2c88..48500bf62801 100644
>>>>>>>> ---
a/drivers/gpu/drm/drm_ioctl.c
>>>>>>>> +++
b/drivers/gpu/drm/drm_ioctl.c
>>>>>>>> @@ -703,6 +703,11 @@
static const struct drm_ioctl_desc
>>>>>>>> drm_ioctls[]
>>>>>>>> = {
>>>>>>>>
DRM_RENDER_ALLOW),
>>>>>>>>
DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_QUERY,
>>>>>>>> drm_syncobj_query_ioctl,
>>>>>>>>
DRM_RENDER_ALLOW),
>>>>>>>> +
DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_GET_SIDEBAND,
>>>>>>>>
drm_syncobj_get_sideband_ioctl,
>>>>>>>> +
DRM_RENDER_ALLOW),
>>>>>>>> +
DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SET_SIDEBAND,
>>>>>>>>
drm_syncobj_set_sideband_ioctl,
>>>>>>>> +
DRM_RENDER_ALLOW),
>>>>>>>> +
>>>>>>>>
DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE,
>>>>>>>>
drm_crtc_get_sequence_ioctl, 0),
>>>>>>>>
DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE,
>>>>>>>>
drm_crtc_queue_sequence_ioctl, 0),
>>>>>>>>
DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE,
>>>>>>>>
drm_mode_create_lease_ioctl, DRM_MASTER),
>>>>>>>> diff --git
a/drivers/gpu/drm/drm_syncobj.c
>>>>>>>>
b/drivers/gpu/drm/drm_syncobj.c
>>>>>>>> index
b927e482e554..c90ef20b9242 100644
>>>>>>>> ---
a/drivers/gpu/drm/drm_syncobj.c
>>>>>>>> +++
b/drivers/gpu/drm/drm_syncobj.c
>>>>>>>> @@ -1150,8 +1150,10 @@
drm_syncobj_reset_ioctl(struct drm_device
>>>>>>>> *dev, void *data,
>>>>>>>> if (ret < 0)
>>>>>>>> return ret;
>>>>>>>> - for (i = 0; i
< args->count_handles; i++)
>>>>>>>> + for (i = 0; i <
args->count_handles; i++) {
>>>>>>>>
drm_syncobj_replace_fence(syncobjs[i], NULL);
>>>>>>>> +
syncobjs[i]->sideband_payload = 0;
>>>>>>>> + }
>>>>>>>>
drm_syncobj_array_free(syncobjs, args->count_handles);
>>>>>>>> @@ -1321,6 +1323,81
@@ int drm_syncobj_query_ioctl(struct
>>>>>>>> drm_device *dev, void
*data,
>>>>>>>> if (ret)
>>>>>>>> break;
>>>>>>>> }
>>>>>>>> +
>>>>>>>> +
drm_syncobj_array_free(syncobjs, args->count_handles);
>>>>>>>> +
>>>>>>>> + return ret;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +int
drm_syncobj_get_sideband_ioctl(struct drm_device *dev,
void
>>>>>>>> *data,
>>>>>>>> +
struct drm_file *file_private)
>>>>>>>> +{
>>>>>>>> + struct
drm_syncobj_timeline_array *args = data;
>>>>>>>> + struct drm_syncobj
**syncobjs;
>>>>>>>> + uint64_t __user
*points = u64_to_user_ptr(args->points);
>>>>>>>> + uint32_t i;
>>>>>>>> + int ret;
>>>>>>>> +
>>>>>>>> + if
(!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
>>>>>>>> + return
-EOPNOTSUPP;
>>>>>>>> +
>>>>>>>> + if (args->pad !=
0)
>>>>>>>> + return -EINVAL;
>>>>>>>> +
>>>>>>>> + if
(args->count_handles == 0)
>>>>>>>> + return -EINVAL;
>>>>>>>> +
>>>>>>>> + ret =
drm_syncobj_array_find(file_private,
>>>>>>>> +
u64_to_user_ptr(args->handles),
>>>>>>>> +
args->count_handles,
>>>>>>>> +
&syncobjs);
>>>>>>>> + if (ret < 0)
>>>>>>>> + return ret;
>>>>>>>> +
>>>>>>>> + for (i = 0; i <
args->count_handles; i++) {
>>>>>>>> +
copy_to_user(&points[i],
&syncobjs[i]->sideband_payload,
>>>>>>>> sizeof(uint64_t));
>>>>>>>> + ret = ret ?
-EFAULT : 0;
>>>>>>>> + if (ret)
>>>>>>>> + break;
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> +
drm_syncobj_array_free(syncobjs, args->count_handles);
>>>>>>>> +
>>>>>>>> + return ret;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +int
drm_syncobj_set_sideband_ioctl(struct drm_device *dev,
void
>>>>>>>> *data,
>>>>>>>> +
struct drm_file *file_private)
>>>>>>>> +{
>>>>>>>> + struct
drm_syncobj_timeline_array *args = data;
>>>>>>>> + struct drm_syncobj
**syncobjs;
>>>>>>>> + uint64_t __user
*points = u64_to_user_ptr(args->points);
>>>>>>>> + uint32_t i;
>>>>>>>> + int ret;
>>>>>>>> +
>>>>>>>> + if
(!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
>>>>>>>> + return
-EOPNOTSUPP;
>>>>>>>> +
>>>>>>>> + if (args->pad !=
0)
>>>>>>>> + return -EINVAL;
>>>>>>>> +
>>>>>>>> + if
(args->count_handles == 0)
>>>>>>>> + return -EINVAL;
>>>>>>>> +
>>>>>>>> + ret =
drm_syncobj_array_find(file_private,
>>>>>>>> +
u64_to_user_ptr(args->handles),
>>>>>>>> +
args->count_handles,
>>>>>>>> +
&syncobjs);
>>>>>>>> + if (ret < 0)
>>>>>>>> + return ret;
>>>>>>>> +
>>>>>>>> + for (i = 0; i <
args->count_handles; i++) {
>>>>>>>> +
copy_from_user(&syncobjs[i]->sideband_payload,
&points[i],
>>>>>>>> sizeof(uint64_t));
>>>>>>>> + ret = ret ?
-EFAULT : 0;
>>>>>>>> + if (ret)
>>>>>>>> + break;
>>>>>>>> + }
>>>>>>>> +
>>>>>>>>
drm_syncobj_array_free(syncobjs, args->count_handles);
>>>>>>>> return ret;
>>>>>>>> diff --git
a/include/drm/drm_syncobj.h b/include/drm/drm_syncobj.h
>>>>>>>> index
6cf7243a1dc5..b587b8e07547 100644
>>>>>>>> ---
a/include/drm/drm_syncobj.h
>>>>>>>> +++
b/include/drm/drm_syncobj.h
>>>>>>>> @@ -61,6 +61,15 @@ struct
drm_syncobj {
>>>>>>>> * @file: A
file backing for this syncobj.
>>>>>>>> */
>>>>>>>> struct file
*file;
>>>>>>>> + /**
>>>>>>>> + *
@sideband_payload: A 64bit side band payload.
>>>>>>>> + *
>>>>>>>> + * We use the
sideband payload value to wait on binary syncobj
>>>>>>>> fences
>>>>>>>> + * to materialize.
It is a reservation mechanism for the
>>>>>>>> signaler to
>>>>>>>> + * express that at
some point in the future a dma fence with
>>>>>>>> the same
>>>>>>>> + * seqno will be put
into the syncobj.
>>>>>>>> + */
>>>>>>>> + u64
sideband_payload;
>>>>>>>> };
>>>>>>>> void
drm_syncobj_free(struct kref *kref);
>>>>>>>> diff --git
a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
>>>>>>>> index
8a5b2f8f8eb9..cffdc6c9772c 100644
>>>>>>>> ---
a/include/uapi/drm/drm.h
>>>>>>>> +++
b/include/uapi/drm/drm.h
>>>>>>>> @@ -946,6 +946,8 @@
extern "C" {
>>>>>>>> #define
DRM_IOCTL_SYNCOBJ_QUERY DRM_IOWR(0xCB, struct
>>>>>>>>
drm_syncobj_timeline_array)
>>>>>>>> #define
DRM_IOCTL_SYNCOBJ_TRANSFER DRM_IOWR(0xCC, struct
>>>>>>>> drm_syncobj_transfer)
>>>>>>>> #define
DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL DRM_IOWR(0xCD,
>>>>>>>> struct
drm_syncobj_timeline_array)
>>>>>>>> +#define
DRM_IOCTL_SYNCOBJ_GET_SIDEBAND DRM_IOR(0xCE, struct
>>>>>>>>
drm_syncobj_timeline_array)
>>>>>>>> +#define
DRM_IOCTL_SYNCOBJ_SET_SIDEBAND DRM_IOWR(0xCF, struct
>>>>>>>>
drm_syncobj_timeline_array)
>>>>>>>> /**
>>>>>>>> * Device specific
ioctls should only be in their respective
>>>>>>>> headers
>>
