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

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

>-----Original Message-----
>From: Trahe, Fiona <fiona.trahe@intel.com>
>Sent: 17 October 2018 20:04
>To: Daly, Lee <lee.daly@intel.com>; Verma, Shally <Shally.Verma@cavium.com>
>Cc: Jozwiak, TomaszX <tomaszx.jozwiak@intel.com>; dev@dpdk.org; akhil.goyal@nxp.com; Trahe, Fiona <fiona.trahe@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@cavium.com>
>> Cc: Jozwiak, TomaszX <tomaszx.jozwiak@intel.com>; dev@dpdk.org; Trahe, Fiona
>> <fiona.trahe@intel.com>; akhil.goyal@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@dpdk.org] On Behalf Of Verma, Shally
>> > Sent: Friday, October 12, 2018 11:16 AM
>> > To: Jozwiak, TomaszX <tomaszx.jozwiak@intel.com>; dev@dpdk.org; Trahe,
>> > Fiona <fiona.trahe@intel.com>; akhil.goyal@nxp.com; De Lara Guarch, Pablo
>> > <pablo.de.lara.guarch@intel.com>
>> > Cc: De@dpdk.org; Lara@dpdk.org; Guarch@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.