Hi All,
Just to summarize, below items have arisen from the initial review. 1) Can the new mempool flag be made default to all the pools and will there be case that new flag functionality would fail for some page sizes.? 2) Adding HW device info(pci dev info) to KNI device structure, will it break KNI on virtual devices in VA or PA mode.? Can someone suggest if any changes required to address above issues. ________________________________ From: dev <dev-boun...@dpdk.org> on behalf of Vamsi Krishna Attunuru <vattun...@marvell.com> Sent: Monday, July 1, 2019 7:21:22 PM To: Jerin Jacob Kollanukkaran; Burakov, Anatoly; dev@dpdk.org Cc: ferruh.yi...@intel.com; olivier.m...@6wind.com; arybche...@solarflare.com Subject: [EXT] Re: [dpdk-dev] [PATCH v6 0/4] add IOVA = VA support in KNI External Email ---------------------------------------------------------------------- ping.. ________________________________ From: Jerin Jacob Kollanukkaran Sent: Thursday, June 27, 2019 3:04:58 PM To: Burakov, Anatoly; Vamsi Krishna Attunuru; dev@dpdk.org Cc: ferruh.yi...@intel.com; olivier.m...@6wind.com; arybche...@solarflare.com Subject: RE: [dpdk-dev] [PATCH v6 0/4] add IOVA = VA support in KNI > -----Original Message----- > From: Burakov, Anatoly <anatoly.bura...@intel.com> > Sent: Tuesday, June 25, 2019 7:09 PM > To: Jerin Jacob Kollanukkaran <jer...@marvell.com>; Vamsi Krishna Attunuru > <vattun...@marvell.com>; dev@dpdk.org > Cc: ferruh.yi...@intel.com; olivier.m...@6wind.com; > arybche...@solarflare.com > Subject: Re: [dpdk-dev] [PATCH v6 0/4] add IOVA = VA support in KNI > > On 25-Jun-19 12:30 PM, Burakov, Anatoly wrote: > > On 25-Jun-19 12:15 PM, Jerin Jacob Kollanukkaran wrote: > >>> -----Original Message----- > >>> From: dev <dev-boun...@dpdk.org> On Behalf Of Burakov, Anatoly > >>> Sent: Tuesday, June 25, 2019 3:30 PM > >>> To: Vamsi Krishna Attunuru <vattun...@marvell.com>; dev@dpdk.org > >>> Cc: ferruh.yi...@intel.com; olivier.m...@6wind.com; > >>> arybche...@solarflare.com > >>> Subject: Re: [dpdk-dev] [PATCH v6 0/4] add IOVA = VA support in KNI > >>> > >>> On 25-Jun-19 4:56 AM, vattun...@marvell.com wrote: > >>>> From: Vamsi Attunuru <vattun...@marvell.com> > >>>> > >>>> ---- > >>>> V6 Changes: > >>>> * Added new mempool flag to ensure mbuf memory is not scattered > >>>> across page boundaries. > >>>> * Added KNI kernel module required PCI device information. > >>>> * Modified KNI example application to create mempool with new > >>>> mempool flag. > >>>> > >>> Others can chime in, but my 2 cents: this reduces the usefulness of > >>> KNI because it limits the kinds of mempools one can use them with, > >>> and makes it so that the code that works with every other PMD > >>> requires changes to work with KNI. > >> > >> # One option to make this flag as default only for packet mempool(not > >> allow allocate on page boundary). > >> In real world the overhead will be very minimal considering Huge page > >> size is 1G or 512M # Enable this flag explicitly only IOVA = VA mode > >> in library. Not need to expose to application # I don’t think, there > >> needs to be any PMD specific change to make KNI with IOVA = VA mode # > >> No preference on flags to be passed by application vs in library. > >> But IMO this change would be > >> needed in mempool support KNI in IOVA = VA mode. > >> > > > > I would be OK to just make it default behavior to not cross page > > boundaries when allocating buffers. This would solve the problem for > > KNI and for any other use case that would rely on PA-contiguous > > buffers in face of IOVA as VA mode. > > > > We could also add a flag to explicitly allow page crossing without > > also making mbufs IOVA-non-contiguous, but i'm not sure if there are > > use cases that would benefit from this. > > On another thought, such a default would break 4K pages in case for packets > bigger than page size (i.e. jumbo frames). Should we care? The hugepage size will not be 4K. Right? Olivier, As a maintainer any thoughts of exposing/not exposing the new mepool flag to Skip the page boundaries? All, Either option is fine, Asking for feedback to processed further?
