[dpdk-dev] [PATCH 2/3] app/compress-perf: add performance measurement

[Jozwiak, TomaszX]

Hi Shally,

> I don't think segsz is required to input then?

Yes, this param. together with others like: input sz and max-num-segs-sgl
gives possibility to find the best performance values set for each PMD, so let's keep it.


Br, Tomek




> -----Original Message-----
> From: Verma, Shally [mailto:Shally.Verma at cavium.com]
> Sent: Sunday, December 2, 2018 7:40 AM
> To: Jozwiak, TomaszX <tomaszx.jozwiak at intel.com>; Trahe, Fiona
> <fiona.trahe at intel.com>; Daly, Lee <lee.daly at intel.com>
> Cc: dev at dpdk.org; akhil.goyal at nxp.com
> Subject: RE: [dpdk-dev] [PATCH 2/3] app/compress-perf: add performance
> measurement
> 
> Ok. Then to keep it simple can we keep input sz and max-num-segs-sgl at
> cmd line input. I don't think segsz is required to input then?
> 
> Thanks
> Shally
> 
> >-----Original Message-----
> >From: Jozwiak, TomaszX <tomaszx.jozwiak at intel.com>
> >Sent: 30 November 2018 20:13
> >To: Verma, Shally <Shally.Verma at cavium.com>; Trahe, Fiona
> ><fiona.trahe at intel.com>; Daly, Lee <lee.daly at intel.com>
> >Cc: dev at dpdk.org; akhil.goyal at nxp.com
> >Subject: RE: [dpdk-dev] [PATCH 2/3] app/compress-perf: add performance
> >measurement
> >
> >External Email
> >
> >Hi Shally,
> >
> >I'm about of sending V5 of compression-perf tool.
> >
> >Our performance testing shows that the number of sgls in a chain can be a
> factor in the performance.
> >So we want to keep this on the cmd line for the performance tool.
> >There are alternatives, like setting the input size and segment size to
> >get the num segments desired, but I prefer to have the option to specify
> the num segments explicitly.
> >We'll document that if the max-num-sgl-segs x seg_sz > input size then
> >segments number in the chain will be lower ( to store all the
> >data)
> >As regards adding the max_nb_segments_per_sgl into the
> >rte_compressdev_info struct we're investigating another workaround to
> this limitation in QAT, so will leave this off the API unless some other PMD
> needs it.
> >In the meantime we'll document the limitation in QAT.
> >
> >Please let me know your thoughts.
> >
> >--
> >Tomek
> >
> >> -----Original Message-----
> >> From: Verma, Shally [mailto:Shally.Verma at cavium.com]
> >> Sent: Wednesday, October 17, 2018 6:48 PM
> >> To: Trahe, Fiona <fiona.trahe at intel.com>; Daly, Lee
> >> <lee.daly at intel.com>
> >> Cc: Jozwiak, TomaszX <tomaszx.jozwiak at intel.com>; dev at dpdk.org;
> >> akhil.goyal at nxp.com
> >> Subject: RE: [dpdk-dev] [PATCH 2/3] app/compress-perf: add
> >> performance measurement
> >>
> >>
> >>
> >> >-----Original Message-----
> >> >From: Trahe, Fiona <fiona.trahe at intel.com>
> >> >Sent: 17 October 2018 22:15
> >> >To: Verma, Shally <Shally.Verma at cavium.com>; Daly, Lee
> >> ><lee.daly at intel.com>
> >> >Cc: Jozwiak, TomaszX <tomaszx.jozwiak at intel.com>; dev at dpdk.org;
> >> >akhil.goyal at nxp.com; Trahe, Fiona <fiona.trahe at intel.com>
> >> >Subject: RE: [dpdk-dev] [PATCH 2/3] app/compress-perf: add
> >> >performance measurement
> >> >
> >> >External Email
> >> >
> >> >> -----Original Message-----
> >> >> From: Verma, Shally [mailto:Shally.Verma at cavium.com]
> >> >> Sent: Wednesday, October 17, 2018 8:43 AM
> >> >> To: Trahe, Fiona <fiona.trahe at intel.com>; Daly, Lee
> >> >> <lee.daly at intel.com>
> >> >> Cc: Jozwiak, TomaszX <tomaszx.jozwiak at intel.com>; dev at dpdk.org;
> >> >> akhil.goyal at nxp.com
> >> >> Subject: RE: [dpdk-dev] [PATCH 2/3] app/compress-perf: add
> >> >> performance measurement
> >> >>
> >> >>
> >> >>
> >> >> >-----Original Message-----
> >> >> >From: Trahe, Fiona <fiona.trahe at intel.com>
> >> >> >Sent: 17 October 2018 20:04
> >> >> >To: Daly, Lee <lee.daly at intel.com>; Verma, Shally
> >> >> ><Shally.Verma at cavium.com>
> >> >> >Cc: Jozwiak, TomaszX <tomaszx.jozwiak at intel.com>; dev at dpdk.org;
> >> >> >akhil.goyal at nxp.com; Trahe, Fiona
> >> >> <fiona.trahe at intel.com>
> >> >> >Subject: RE: [dpdk-dev] [PATCH 2/3] app/compress-perf: add
> >> >> >performance measurement
> >> >> >
> >> >> >External Email
> >> >> >
> >> >> >Hi Shally, Lee,
> >> >> >
> >> >> >> -----Original Message-----
> >> >> >> From: Daly, Lee
> >> >> >> Sent: Monday, October 15, 2018 8:10 AM
> >> >> >> To: Verma, Shally <Shally.Verma at cavium.com>
> >> >> >> Cc: Jozwiak, TomaszX <tomaszx.jozwiak at intel.com>;
> dev at dpdk.org;
> >> >> >> Trahe, Fiona <fiona.trahe at intel.com>; akhil.goyal at nxp.com
> >> >> >> Subject: RE: [dpdk-dev] [PATCH 2/3] app/compress-perf: add
> >> >> >> performance measurement
> >> >> >>
> >> >> >> Thanks for your input Shally see comments below.
> >> >> >>
> >> >> >>
> >> >> >> I will be reviewing these changes while Tomasz is out this week.
> >> >> >>
> >> >> >> > -----Original Message-----
> >> >> >> > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Verma,
> >> >> >> > Shally
> >> >> >> > Sent: Friday, October 12, 2018 11:16 AM
> >> >> >> > To: Jozwiak, TomaszX <tomaszx.jozwiak at intel.com>;
> >> dev at dpdk.org;
> >> >> >> > Trahe, Fiona <fiona.trahe at intel.com>; akhil.goyal at nxp.com; De
> >> >> >> > Lara Guarch, Pablo <pablo.de.lara.guarch at intel.com>
> >> >> >> > Cc: De at dpdk.org; Lara at dpdk.org; Guarch at dpdk.org
> >> >> >> > Subject: Re: [dpdk-dev] [PATCH 2/3] app/compress-perf: add
> >> >> >> > performance measurement
> >> >> >> >
> >> >> >///
> >> >> >
> >> >> >> >Also, why do we need --max-num-  sgl-segs as an input option
> >> >> >> >from user? Shouldn't input_sz and seg_sz  internally decide on
> >> >> >> >num-segs?
> >> >> >> > Or is it added to serve some other different purpose?
> >> >> >> Will have to get back to you on this one, seems illogical to
> >> >> >> get this input from user, But I will have to do further
> >> >> >> investigation to find if
> >> there was a different purpose.
> >> >> >
> >> >> >[Fiona] Some PMDs have a limit on how many links can be in an sgl
> >> >> >chain, e.g. in QAT case the PMD allocates a pool of internal
> >> >> >structures of a suitable size during device initialisation, this
> >> >> >is not a hard
> >> limit but can be configured in .config to give the user control over
> >> the memory resources allocated.
> >> >> >This perf-tool max-num-sgl-segs is so the user can pick a value
> >> >> ><=
> >> whatever the PMD's max is.
> >> >>
> >> >> Then also, I believe this could be taken care internally by an app.
> >> >> App can choose convenient number of sgl segs as per PMD capability
> >> >> and input sz and chunk sz selected by user.
> >> >> Just my thoughts.
> >> >[Fiona] Then we'd need to add this capability to the API, e.g. add
> >> >uint16_t max_nb_segments_per_sgl into the rte_compressdev_info
> struct.
> >> >Special case 0 means no limit.
> >> >We did consider this before, I can't remember why we didn't do it, I
> >> >think
> >> it's needed.
> >> >I'll push an API patch for this in 19.02 and we can remove the
> >> >--max-num-sgl-segs param from the performance tool and hardcode it
> >> >in
> >> the tool in the meantime.
> >> >Ok?
> >> Yea. Sounds better.