> -----Original Message----- > From: Burakov, Anatoly <[email protected]> > Sent: Tuesday, July 16, 2019 8:03 PM > To: Jerin Jacob Kollanukkaran <[email protected]>; [email protected]; John > McNamara <[email protected]>; Marko Kovacevic > <[email protected]> > Cc: [email protected]; [email protected] > Subject: [EXT] Re: [dpdk-dev] [PATCH v2 4/4] eal: select IOVA mode as VA for > default case > > On 16-Jul-19 2:46 PM, [email protected] wrote: > > From: Jerin Jacob <[email protected]> > > > > When bus layer selected the preferred mode as RTE_IOVA_DC then select > > the IOVA mode as RTE_IOVA_VA. > > > > The RTE_IOVA_VA selected as the default because, > > > > 1) All drivers work in RTE_IOVA_VA mode, irrespective of physical > > address availability. > > > > 2) By default, the mempool, first asks for IOVA-contiguous memory > > using RTE_MEMZONE_IOVA_CONTIG and this is slow in IOVA as PA mode > and > > it may affect the application boot time. > > > > Signed-off-by: Jerin Jacob <[email protected]> > > --- > > I should celebrate now :D > > > doc/guides/prog_guide/env_abstraction_layer.rst | 10 ++++++++-- > > lib/librte_eal/linux/eal/eal.c | 6 ++---- > > 2 files changed, 10 insertions(+), 6 deletions(-) > > > > diff --git a/doc/guides/prog_guide/env_abstraction_layer.rst > > b/doc/guides/prog_guide/env_abstraction_layer.rst > > index 77307e3a6..1b0343eee 100644 > > --- a/doc/guides/prog_guide/env_abstraction_layer.rst > > +++ b/doc/guides/prog_guide/env_abstraction_layer.rst > > @@ -445,8 +445,14 @@ kernels. > > - if the preferred mode is RTE_IOVA_PA but there is no access to Physical > > Addresses, then EAL init will fail early, since later probing of the > > devices > > would fail anyway, > > -- if the preferred mode is RTE_IOVA_DC then based on the Physical > > Addresses > > - availability, the preferred mode is adjusted to RTE_IOVA_PA or > RTE_IOVA_VA. > > +- if the preferred mode is RTE_IOVA_DC then select the IOVA mode as > RTE_IOVA_VA. > > + The RTE_IOVA_VA selected as the default because, > > + > > +#. All drivers work in RTE_IOVA_VA mode, irrespective of physical address > availability. > > Is there anywhere we can document that any new driver must support both > before being accepted?
Not sure why new drivers need to support both PA and VA. Do you mean VA? And not sure where to document this as well if need. > > > + > > +#. By default, the mempool, first asks for IOVA-contiguous memory using > ``RTE_MEMZONE_IOVA_CONTIG``, > > + and this is slow in IOVA as PA mode and it may affect the application > boot time. > > I would also add a point about usability improvement for use-cases which > require large amounts of IOVA-contiguous memory. I will add in next version: How about the following, Let me know if any change required. #. It is easy to enable large amount of IOVA-contiguous memory use-cases with IOVA in VA mode. > > Otherwise, > > Acked-by: Anatoly Burakov <[email protected]>
