On 12 May 2016 at 13:06, Santosh Shukla <santosh.shukla at caviumnetworks.com> wrote: > On Thu, May 12, 2016 at 11:42:26AM +0800, Jianbo Liu wrote: >> On 12 May 2016 at 11:17, Santosh Shukla >> <santosh.shukla at caviumnetworks.com> wrote: >> > On Thu, May 12, 2016 at 10:01:05AM +0800, Jianbo Liu wrote: >> >> On 12 May 2016 at 02:25, Stephen Hemminger <stephen at >> >> networkplumber.org> wrote: >> >> > On Wed, 11 May 2016 22:32:16 +0530 >> >> > Jerin Jacob <jerin.jacob at caviumnetworks.com> wrote: >> >> > >> >> >> On Wed, May 11, 2016 at 08:22:59AM -0700, Stephen Hemminger wrote: >> >> >> > On Wed, 11 May 2016 19:17:58 +0530 >> >> >> > Hemant Agrawal <hemant.agrawal at nxp.com> wrote: >> >> >> > >> >> >> > > IGB_UIO not supported for arm64 arch in kernel so disable. >> >> >> > > >> >> >> > > Signed-off-by: Hemant Agrawal <hemant.agrawal at nxp.com> >> >> >> > > Reviewed-by: Santosh Shukla <santosh.shukla at caviumnetworks.com> >> >> >> > >> >> >> > Really, I have use IGB_UIO on ARM64 >> >> >> >> >> >> May I know what is the technical use case for igb_uio on arm64 >> >> >> which cannot be addressed through vfio or vfioionommu. >> >> > >> >> > I was running on older kernel which did not support vfioionommu mode. >> >> >> >> As I said, most of DPDK developers are not kernel developers. They may >> >> have their own kernel tree, and couldn't like to upgrade to latest >> >> kernel. >> >> They can choose to use or not use igb_uio when binding the driver. But >> >> blindly disabling it in the base config seems unreasonable. >> > >> > if user keeping his own kernel so they could also keep IGB_UIO=y in their >> > local >> Most likely they don't have local dpdk tree. They write their own >> applications, complie and link to dpdk lib, then done. >> >> > dpdk tree. Why are you imposing user-x custome depedancy on upstream dpdk >> > base >> Customer requiremnts is important. I want they can choose the way they like. >> > > so you choose to keep igb_uio option, provided arch doesn't support? > new user did reported issues with igb_uio for arm64, refer this thread [1], as > well hemanth too faced issues. we want to avoid that. > > If customer maintaing out-of-tree kernel then he can also switch to vfio-way. > isn;t it? > >> > config. Is it not enough for explanation that - Base config ie.. armv8 >> > doesn;t >> > support pci mmap, so igb_uio is n/a. New user wont able to build/run >> > dpdk/arm64 >> > in igb_uio-way, He'll prefer to use upstream stuff. I think, you are not >> > making >> You are wrong, he can build dpdk. If he like to use upstream without >> patching, he can use vfio. > > I disagree, we want to avoid [1] for new user. > >> But you can't ignore the need from old user which is more comfortable >> with older kernel. >> > arm/arm64 dpdk support recently added and I am guessing, most likely customer > using near latest kernel, switching to vfio won't be so difficult. > > Or can you take up responsibility of upstreaming pci mmap patch, then we don't > need this patch. > > [1] http://dpdk.org/ml/archives/dev/2016-January/031313.html
Can you read carefully about the guide at http://dpdk.org/doc/guides/linux_gsg/build_dpdk.html? It says to use uio_pci_generic, igb_uio or vfio-pci. Could it be possible that the user in that thread has already read and tried them all and found that he can't enable vifo with his kernel, and igb_uio is the easy way for him and asked for help from community? If so, we have no choice but keeping igb_uio enabled. He use lsmod to show us the modules, most likely he know vifo-pci. Below are the details on modules, hugepages and device binding. root at arm64:~# lsmod Module Size Used by rte_kni 292795 0 igb_uio 4338 0 ixgbe 184456 0
