On Sat, Jan 26, 2019 at 11:09:45AM -0600, Steve Wise wrote: > > > > -----Original Message----- > > From: linux-rdma-owner@xxxxxxxxxxxxxxx <linux-rdma- > > owner@xxxxxxxxxxxxxxx> On Behalf Of Shiraz Saleem > > Sent: Saturday, January 26, 2019 10:59 AM > > To: dledford@xxxxxxxxxx; jgg@xxxxxxxx; linux-rdma@xxxxxxxxxxxxxxx > > Cc: Shiraz, Saleem <shiraz.saleem@xxxxxxxxx>; Steve Wise > > <swise@xxxxxxxxxxx> > > Subject: [PATCH RFC 05/12] RDMA/cxgb4: Use for_each_sg_dma_page > > iterator on umem SGL > > > > From: "Shiraz, Saleem" <shiraz.saleem@xxxxxxxxx> > > > > Use the for_each_sg_dma_page iterator variant to walk the umem > > DMA-mapped SGL and get the page DMA address. This avoids the extra > > loop to iterate pages in the SGE when for_each_sg iterator is used. > > > > Additionally, purge umem->page_shift usage in the driver > > as its only relevant for ODP MRs. Use system page size and > > shift instead. > > Hey Shiraz, Doesn't umem->page_shift allow registering huge pages > efficiently? IE is umem->page_shift set for the 2MB shift if the memory in > this umem region is from the 2MB huge page pool? > Not quite. For non-ODP MRs, its just the shift w.r.t the default arch page size (4K on x86), i.e. PAGE_SHIFT. Even if the umem is backed by huge pages. https://elixir.bootlin.com/linux/v5.0-rc3/source/drivers/infiniband/core/umem.c#L126 Shiraz
