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

[Verma, Shally]

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.