Hi alex/guys:
No such situation exists. there is always a rendernode.
=======>
if so, why the logic in function "kfd_process_device_init_vm" has a situation
that in consideration of the "drm render file" not exsists? and even im
"kfd_bind_process_to_device" therea are lazy vm conetxt binding " err =
kfd_process_device_init_vm(pdd, NULL);" which pass NULL pointer as drm file
directly ? if so , can the another path on scenario drm_file empty
"amdgpu_amdkfd_gpuvm_create_process_vm" call is redundant?
Thank you!
774 int kfd_process_device_init_vm(struct kfd_process_device *pdd,
775 ¦ struct file *drm_file)
776 {
777 struct kfd_process *p;
778 struct kfd_dev *dev;
779 int ret;
780
781 if (pdd->vm)
782 return drm_file ? -EBUSY : 0;
783
784 p = pdd->process;
785 dev = pdd->dev;
786
787 if (drm_file)
788 ret = amdgpu_amdkfd_gpuvm_acquire_process_vm(
789 dev->kgd, drm_file, p->pasid,
790 &pdd->vm, &p->kgd_process_info, &p->ef);
791 else
792 ret = amdgpu_amdkfd_gpuvm_create_process_vm(dev->kgd,
p->pasid,
793 &pdd->vm, &p->kgd_process_info, &p->ef);
794 if (ret) {
795 pr_err("Failed to create process VM object\n");
796 return ret;
797 }
At 2024-03-06 22:45:13, "Deucher, Alexander" <[email protected]> wrote:
[Public]
No such situation exists. there is always a rendernode.
Alex
From: 曹子龙 <[email protected]>
Sent: Wednesday, March 6, 2024 12:25 AM
To: [email protected] <[email protected]>
Cc: Deucher, Alexander <[email protected]>; Yat Sin, David
<[email protected]>; Kuehling, Felix <[email protected]>
Subject: Re:RE: Why has to offer "/dev/drv/render128" fd when running ROCm demo?
Hi felix:
Thanks for your kindly help.
i still has a question, if on a pure-compute platform, which has no
/dev/dri/render node, but only with a single /dev/kfd node, how the compue
scenario works since that wei have no "render" fd exists?
is such platfom(without render node) exists?
thanks for your kindly help.!
BRs
zlcao.
At 2024-03-06 04:43:30, "Kuehling, Felix" <[email protected]> wrote:
[AMD Official Use Only - General]
I already answered this question in a reply to another email that was addressed
to me:
The render nodes are used for CPU mapping of VRAM with mmap calls and an offset
that identifies the BO. The render node also creates the GPU virtual address
space that is used by KFD to create the GPU memory mappings. Applications that
use both graphics and compute can share the same GPU virtual address space in
this way.
Zlcao, in the future, this type of question may be better addressed to a
mailing list such as [email protected], instead of writing
separately to different maintainers.
Regards,
Felix
From: Deucher, Alexander <[email protected]>
Sent: Tuesday, March 5, 2024 3:17 PM
To:曹子龙 <[email protected]>; Kuehling, Felix <[email protected]>; Yat Sin,
David <[email protected]>
Subject: Re: Why has to offer "/dev/drv/render128" fd when running ROCm demo?
[AMD Official Use Only - General]
+ Felix, David to comment.
From:曹子龙 <[email protected]>
Sent: Tuesday, March 5, 2024 8:46 AM
To: Deucher, Alexander <[email protected]>
Subject: Why has to offer "/dev/drv/render128" fd when running ROCm demo?
Hi alexander.:
sorry for bother. but i really need some help to deal with my puzzle.
i am a freshman to AMD GPU Driver, NOW i am trying to write a simple demo to
use "/dev/kfd" and do some vram alloc/free tests, but i found you must do the
right "AMDKFD_IOC_ACQUIRE_VM" ioctl comamnd before you try GPU to do vram
allocation and other things. from the kfd driver code,the pre-condition to do
the right "AMDKFD_IOC_ACQUIRE_VM" is to offer a "/dev/drv/render128" fd to the
parameters.
so, why need to do this? kfd is used for compute, but "/dev/dri/render128" is
specify to gfx usaged, why must open the "/dev/dri/render128" during the KFD
compute scenario?
thanks for your kindly help!
BRs
zlcao.
