Thread (35 messages) 35 messages, 6 authors, 2022-05-19

Re: [EXTERNAL] Re: [PATCH 05/12] net: mana: Set the DMA device max page size

From: Jason Gunthorpe <jgg@ziepe.ca>
Date: 2022-05-18 16:05:35
Also in: linux-hyperv, linux-rdma, lkml

On Wed, May 18, 2022 at 05:59:00AM +0000, Ajay Sharma wrote:
Thanks Long. 
Hello Jason,
I am the author of the patch.
To your comment below : 
" As I've already said, you are supposed to set the value that limits to ib_sge and *NOT* the value that is related to ib_umem_find_best_pgsz. It is usually 2G because the ib_sge's typically work on a 32 bit length."

The ib_sge is limited by the __sg_alloc_table_from_pages() which
uses ib_dma_max_seg_size() which is what is set by the eth driver
using dma_set_max_seg_size() . Currently our hw does not support
PTEs larger than 2M.
*sigh* again it has nothing to do with *PTEs* in the HW.

Jason
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help