Re: Problem Pinning Physical Memory

Tom Tucker
2010-11-30T20:26:26Z

On 11/30/10 9:24 AM, Alan Cook wrote:
>> Tom Tucker<tom@...> writes:
>>
>> Yes. I removed the new verb and followed Jason's recommendation of adding
>> this support to the core reg_mr support. I used the type bits in the vma
>> struct to determine the type of memory being registered and just did the
>> "right thing."
>>
>> I'll repost in the the next day or two.
>>
>> Tom
>>
> Tom,
>
> Couple of questions:
>
> I noticed that OFED 1.5.3 was released last week. Are the changes you speak of
> part of that release?
No.
> If not, is there an alternate branch/project that I should
> be looking at or into to for the mentioned changes?
The patch will be against the top-of-tree Linux kernel.
> Also, I am inferring that the changes allowing the registering of physical
> memory will only happen if my application is running in kernel space.

Actually, no.

> Is this
> correct? or will I be able to register the physical memory from user space now
> as well?
What I implemented was support for mmap'd memory. In practical terms for
your application you would write a driver that supported the mmap file op.
The driver's mmap routine would ioremap the pci memory of interest and
stuff it in the provided vma. The user-mode app then ibv_reg_mr the
address and length returned by mmap.

Make sense?
Tom

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