Dedicated BOs waste memory and are also a significant cause of CPU
overhead when applications use hundreds of them per frame due to
all the work the kernel has to do to page in all these BOs for a job.
The UE4 Vehicle demo was hitting this causing it to freeze and stutter
under 1fps.
The hardware allows us to setup groups of 16 queries in consecutive
4-byte addresses, requiring only that each group of 16 queries is
aligned to a 1024 byte boundary. With this change, we allocate all
the queries in a pool in a single BO and we assign them different
offsets based on the above restriction. This eliminates the freezes
and stutters in the Vehicle sample.
One caveat of this solution is that we can only wait or test for
completion of a query by testing if the GPU is still using its BO,
which basically means that we can only wait for all active queries
in a pool to complete and not just the ones being requested by the
API. Since the Vulkan recommendation is to use a different query
pool per frame this should not be a big issue though.
If this ever becomes a problem (for example if an application does't
follow the recommendation and instead allocates a single pool and
splits its queries between frames), we could try to group queries
in a pool into a number of BOs to try and find a balance, but for
now this should work fine in most cases.
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10253>
Used as reference Hyujun's commit
5d3fdbc52b, that does the same for
turnip.
This commit also replaces in several cases alloc for zalloc, and adds
checks on more Destroy methods if the object to be free is NULL or
not. Most of them were needed to avoid crashes/weird behaviour due
trying to use un-initialized data. Note that now that vk_object_free
iterates over a array, making it more against un-initialized or just
NULL data.
Additionally, using zalloc we can also remove some memset to 0. In
fact we needed to remove them, as if not, they would override the
vk_object_base object to 0 (the alternative would me doing a memset
computing a pointer offset, but that's is not needed as we can just
use zalloc).
v2:
* Call memset(0) on reused descriptor sets when calling
ResetDescriptorPool, not when reallocating them (Iago)
* Add null check when calling DestroyImageView (detected by a full CTS run)
v3: Fixed rebase conflicts after last meta copy/clear changes
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7627>
V3D doesn't provide any means to acquire timestamps from the GPU
so we have to implement these in the CPU.
v2: enable timestampComputeAndGraphics and set timestampPeriod (Piñeiro)
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7373>
Heavily based on the already existing for the v3d OpenGL driver, but
without references, and with some extra OOM checks (Vulkan CTS has
several OOM tests).
With this commit v3dv_bo_alloc and v3dv_bo_free became frontends to
the bo_cache. The former tries to get a BO from the cache if possible,
and the latter stores the BO on the cache if possible. The former also
adds a new parameter to point if the BO to allocate is private.
As v3d we are only caching private BOs, those created by the driver
for internal use (like CLs, tile_alloc, etc). They are the ones with
the highest change of being reused (for example, CL BOs are always
4KB, so they can always be reused). User-created BOs can have any
size, including some very large ones for buffers and images, which
makes them far less likely to be reused and would add a lot of memory
pressure if we decided to cache them.
In any case, in practice, we found that we could get a performance
improvement by caching also user-created BOs, but that would need more
care and an analysis to decide which ones makes sense. Would also
require to change how the cached BOs are stored by size. Right now
there are an array of list_head, that doesn't work well with big
BOs. If done, that would be handled on a separate commit.
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6766>
The design for queries in Vulkan requires that some commands execute
in the GPU as part of a command buffer. Unfortunately, V3D doesn't
really have supprt for this, which means that we need to execute them
in the CPU but we still need to make it look as if they happened
inside the comamnd buffer from the point of view of the user, which
adds certain hassle.
The above means that in some cases we need to do CPU waits for certain
parts of the command buffer to execute so we can then run the CPU
code. For exmaple, we need to wait before executing a query resets
just in case the GPU is using them, and we have to do a CPU wait wait
for previous GPU jobs to complete before copying query results if the
user has asked us to do that. In the future, we may want to have
submission thread instead so we don't block the main thread in these
scenarios.
Because we now need to execute some tasks in the CPU as part of a
command buffer, this introduces the concept of job types, there is one
type for all GPU jobs, and then we have one type for each kind of job
that needs to execute in the CPU. CPU jobs are executed by the queue
in order just like GPU jobs, only that they are exclusively CPU tasks.
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6766>
