Hi Zicao,

that won't work any more the render Node is mandatory for correct ROCm operation by now.

Regards,
Christian.

Am 06.03.24 um 06:25 schrieb 曹子龙:
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] <mailto:[email protected]>>
    *Sent:* Tuesday, March 5, 2024 8:46 AM
    *To:* Deucher, Alexander <[email protected]
    <mailto:[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.

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