How to use IB netlink infrastructure

How to use IB netlink infrastructure

[Daniel Ng]

Hi, I'm new to IB and RDMA.

Can I use the IB netlink infrastructure to produce actual RDMA data transfers?

If so, can you please give an example showing the path of function calls? I
would like to see how get_user_pages() ultimately gets called as a result of a
netlink operation.

If this is not possible, what is the actual entry point in the IB kernel code
that results in a call to get_user_pages()?  

Cheers,
Daniel

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Re: How to use IB netlink infrastructure

[Daniel Ng]

Hi,

It's been a few days since I posted this question,
but I've had no responses so far.

Can anyone help please?

If I'm asking on the wrong list, please suggest an alternative one.

Cheers,
Daniel

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RE: How to use IB netlink infrastructure

[Hefty, Sean]

> It's been a few days since I posted this question,
> but I've had no responses so far.

Can I use the IB netlink infrastructure to produce actual RDMA data transfers?

no

If this is not possible, what is the actual entry point in the IB kernel code
that results in a call to get_user_pages()?

I believe the memory registration calls will result in this being called.  Look for ib_uverbs_reg_mr.

> If I'm asking on the wrong list, please suggest an alternative one.

This is the correct list.

- Sean
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Re: How to use IB netlink infrastructure

[Daniel Ng]

Hefty, Sean <sean.hefty@...> writes:
>> What is the actual entry point in the IB kernel code
>> that results in a call to get_user_pages()?
> 
> I believe the memory registration calls will result in this being called.  
>Look for ib_uverbs_reg_mr.

Thanks for your helpful suggestions Sean.

I've noticed this article on LWN.net:

http://lwn.net/Articles/133649/

It was written in 2005 and points out some shortcomings with using
get_user_pages() for RDMA. Do you know if these shortcomings have been addressed
since 2005?

If not, is there perhaps another way RDMA has been implemented in the kernel?

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