[dpdk-stable] [19.11 4/4] crypto/qat: add minimum enq threshold

[Ali Alnubani]

Hi,

> -----Original Message-----
> From: stable <stable-bounces at dpdk.org> On Behalf Of Trahe, Fiona
> Sent: Friday, August 7, 2020 6:24 PM
> To: Luca Boccassi <bluca at debian.org>; Kusztal, ArkadiuszX
> <arkadiuszx.kusztal at intel.com>
> Cc: stable at dpdk.org
> Subject: Re: [dpdk-stable] [19.11 4/4] crypto/qat: add minimum enq
> threshold
> 
> Thanks Luca
> 
> > -----Original Message-----
> > From: Luca Boccassi <bluca at debian.org>
> > Sent: Friday, August 7, 2020 3:53 PM
> > To: Kusztal, ArkadiuszX <arkadiuszx.kusztal at intel.com>; Trahe, Fiona
> > <fiona.trahe at intel.com>
> > Cc: stable at dpdk.org
> > Subject: Re: [dpdk-stable] [19.11 4/4] crypto/qat: add minimum enq
> > threshold
> >
> > On Fri, 2020-08-07 at 14:57 +0200, Arek Kusztal wrote:
> > > [ upstream commit 47c3f7a41a26c9943f9804691d03828b2ce09f40 ]
> > >
> > > This patch adds minimum enqueue threshold to Intel QuickAssist
> > > Technology PMD.
> > > It is an optimisation, configured by a command line option, which
> > > can be used to reduce MMIO write occurrences.
> > >
> > > Cc: stable at dpdk.org
> > >
> > > Signed-off-by: Fiona Trahe <fiona.trahe at intel.com>
> > > Signed-off-by: Arek Kusztal <arkadiuszx.kusztal at intel.com>
> > > ---
> > >  doc/guides/cryptodevs/qat.rst       | 18 +++++++
> > >  drivers/common/qat/qat_common.c     |  3 ++
> > >  drivers/common/qat/qat_common.h     |  3 ++
> > >  drivers/common/qat/qat_device.c     | 99
> ++++++++++++++++++++++++++++++++-----
> > >  drivers/common/qat/qat_device.h     | 22 +++++++--
> > >  drivers/common/qat/qat_qp.c         | 10 ++++
> > >  drivers/common/qat/qat_qp.h         |  3 ++
> > >  drivers/compress/qat/qat_comp_pmd.c | 14 +++++-
> > > drivers/compress/qat/qat_comp_pmd.h |  4 +-
> > >  drivers/crypto/qat/qat_asym_pmd.c   | 14 +++++-
> > >  drivers/crypto/qat/qat_asym_pmd.h   |  4 +-
> > >  drivers/crypto/qat/qat_sym_pmd.c    | 14 +++++-
> > >  drivers/crypto/qat/qat_sym_pmd.h    |  4 +-
> > >  13 files changed, 190 insertions(+), 22 deletions(-)
> > >
> > > diff --git a/doc/guides/cryptodevs/qat.rst
> > > b/doc/guides/cryptodevs/qat.rst index 5135703..aa3cdcf 100644
> > > --- a/doc/guides/cryptodevs/qat.rst
> > > +++ b/doc/guides/cryptodevs/qat.rst
> > > @@ -273,6 +273,24 @@ allocated while for GEN1 devices, 12 buffers
> > > are allocated, plus 1472 bytes
> > over
> > >  	larger than the input size).
> > >
> > >
> > > +Running QAT PMD with minimum threshold for burst size
> > > +~~~~~~~~~~~~~~~~~~~~~~~~
> > > +
> > > +If only a small number or packets can be enqueued. Each enqueue
> causes an expensive MMIO write.
> > > +These MMIO write occurrences can be optimised by setting any of the
> > > +following parameters
> > > +- qat_sym_enq_threshold
> > > +- qat_asym_enq_threshold
> > > +- qat_comp_enq_threshold
> > > +When any of these parameters is set rte_cryptodev_enqueue_burst
> > > +function will return 0 (thereby avoiding an MMIO) if the device is
> > > +congested and number of packets possible to enqueue is smaller.
> > > +To use this feature the user must set the parameter on process start as
> a device additional parameter:
> > > + .example: '-w
> 03:01.1,qat_sym_enq_threshold=32,qat_comp_enq_threshold=16'
> > > +All parameters can be used with the same device regardless of
> > > +order. Parameters are separated by comma. When the same parameter
> > > +is used more than once first occurrence of the parameter is used.
> > > +Maximum threshold that can be set is 32.
> > > +
> > >  Device and driver naming
> > >  ~~~~~~~~~~~~~~~~~~~~~~~
> >
> > Normally I wouldn't accept a patch that adds new command line
> > features, but given it's restricted to a single PMD _and_ the feature
> > is present in the first short term release after 19.11 (20.02) thus
> > allowing non- breaking upgrades, I'll merge the series.
> >
> > --
> > Kind regards,
> > Luca Boccassi

This change is causing a warning when building the html guides:

"""
$ make doc-guides-html > /dev/null

/tmp/dpdk-stable/doc/guides/cryptodevs/qat.rst:277: WARNING: Title underline too short.

Running QAT PMD with minimum threshold for burst size
~~~~~~~~~~~~~~~~~~~~~~~~
/tmp/dpdk-stable/doc/guides/cryptodevs/qat.rst:277: WARNING: Title underline too short.

Running QAT PMD with minimum threshold for burst size
~~~~~~~~~~~~~~~~~~~~~~~~
/tmp/dpdk-stable/doc/guides/cryptodevs/qat.rst:288: WARNING: Unexpected indentation.
/tmp/dpdk-stable/doc/guides/cryptodevs/qat.rst:289: WARNING: Block quote ends without a blank line; unexpected unindent.
"""

Reproduces on both Ubuntu 18.04 LTS with sphinx-build 1.6.7, and Ubuntu 20.04 with sphinx-build 1.8.5.

Regards,
Ali