[openib-general] kernel mode

[john t]

Hi,

A general doubt.

If I write a kernel program (linux kernel module) to send and receive data
using IB, will it perform better then its user mode counterpart. Unlike user
mode, in  kernel mode, I think it is possible to allocate physically
contiguous memory using "kmalloc or alloc_pages" which means HCAs need not
do any address translation (i.e. no need of page table lookup as I guess in
this case virtual address and physical address will differ only by a fixed
offset) for copying data into main memory. Besides I think traditional DMAs
give better performance with contiguous memory and use a special GFP_DMA
zone. Moreover polling a CQ may be more efficient in kernel. Is this
correct?

Regards,
John T.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openfabrics.org/pipermail/general/attachments/20060911/7928ad2b/attachment.html>