Re: [dpdk-dev] [PATCH] compressdev: add feature flag to specify where processing is done

["Verma, Shally" <Shally.Verma@cavium.com>]

>-----Original Message-----
>From: Trahe, Fiona <fiona.trahe@intel.com>
>Sent: 18 December 2018 20:13
>To: Stephen Hemminger <stephen@networkplumber.org>
>Cc: dev@dpdk.org; akhil.goyal@nxp.com; Jozwiak, TomaszX <tomaszx.jozwiak@intel.com>; Verma, Shally
><Shally.Verma@cavium.com>; Gupta, Ashish <Ashish.Gupta@cavium.com>; Daly, Lee <lee.daly@intel.com>; Luse, Paul E
><paul.e.luse@intel.com>; Trahe, Fiona <fiona.trahe@intel.com>
>Subject: RE: [dpdk-dev] [PATCH] compressdev: add feature flag to specify where processing is done
>
>External Email
>
>Hi Stephen
>
>//snip//
>> > > Subject: Re: [dpdk-dev] [PATCH] compressdev: add feature flag to specify where processing is done
>> > >
>> > > On Tue, 20 Nov 2018 01:39:48 +0000
>> > > Fiona Trahe <fiona.trahe@intel.com> wrote:
>> > >
>> > > > A new device feature flag, RTE_COMPDEV_FF_SW_OP_DONE_IN_DEQUEUE
>> > > > is added. A PMD which processes operations using a software
>> > > > acceleration engine should set this if the bulk of the
>> > > > processing is done during the dequeue. It should leave it
>> > > > cleared if the bulk of the processing is done during the
>> > > > enqueue (default).
>> > > > An application may find this useful for tuning.
>> > > >
>> > > > Signed-off-by: Fiona Trahe <fiona.trahe@intel.com>
>> > >
>> > > What application? or is this "if we build it they will come?"
>> > [Fiona] Our storage team asked for this, so not quite.
>> > Seems like it might by generically useful, so a bit of the latter too :)
>> > Would you prefer I removed that line?
>>
>> Hopefully, there would be one or more open source projects using the API.
>> I just did a survey of DPDK an 1/3 of it is never used by any open source
>> project.  Hate to see more dead code and special cases created.
>>
>> At least, some example code in examples would help. Something like a simple
>> in memory compressed storage server using a network API (SMB?/SSH?/FTP?)
>[Fiona] There is no compressdev sample app yet.
>However I've double-checked with the SPDK team, they're currently integrating
>compressdev and intend to push a patch to SPDK - a storage open-source project - using this flag.
[Shally] Am seeing some of our HW based PMD also leveraging this choice. So I would say to make it generic feature flag instead of SW specific.

Thanks
Shally