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 <[email protected]> >Sent: 30 November 2018 20:13 >To: Verma, Shally <[email protected]>; Trahe, Fiona ><[email protected]>; Daly, Lee <[email protected]> >Cc: [email protected]; [email protected] >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:[email protected]] >> Sent: Wednesday, October 17, 2018 6:48 PM >> To: Trahe, Fiona <[email protected]>; Daly, Lee <[email protected]> >> Cc: Jozwiak, TomaszX <[email protected]>; [email protected]; >> [email protected] >> Subject: RE: [dpdk-dev] [PATCH 2/3] app/compress-perf: add performance >> measurement >> >> >> >> >-----Original Message----- >> >From: Trahe, Fiona <[email protected]> >> >Sent: 17 October 2018 22:15 >> >To: Verma, Shally <[email protected]>; Daly, Lee >> ><[email protected]> >> >Cc: Jozwiak, TomaszX <[email protected]>; [email protected]; >> >[email protected]; Trahe, Fiona <[email protected]> >> >Subject: RE: [dpdk-dev] [PATCH 2/3] app/compress-perf: add performance >> >measurement >> > >> >External Email >> > >> >> -----Original Message----- >> >> From: Verma, Shally [mailto:[email protected]] >> >> Sent: Wednesday, October 17, 2018 8:43 AM >> >> To: Trahe, Fiona <[email protected]>; Daly, Lee >> >> <[email protected]> >> >> Cc: Jozwiak, TomaszX <[email protected]>; [email protected]; >> >> [email protected] >> >> Subject: RE: [dpdk-dev] [PATCH 2/3] app/compress-perf: add >> >> performance measurement >> >> >> >> >> >> >> >> >-----Original Message----- >> >> >From: Trahe, Fiona <[email protected]> >> >> >Sent: 17 October 2018 20:04 >> >> >To: Daly, Lee <[email protected]>; Verma, Shally >> >> ><[email protected]> >> >> >Cc: Jozwiak, TomaszX <[email protected]>; [email protected]; >> >> >[email protected]; Trahe, Fiona >> >> <[email protected]> >> >> >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 <[email protected]> >> >> >> Cc: Jozwiak, TomaszX <[email protected]>; [email protected]; >> >> >> Trahe, Fiona <[email protected]>; [email protected] >> >> >> 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:[email protected]] On Behalf Of Verma, >> >> >> > Shally >> >> >> > Sent: Friday, October 12, 2018 11:16 AM >> >> >> > To: Jozwiak, TomaszX <[email protected]>; >> [email protected]; >> >> >> > Trahe, Fiona <[email protected]>; [email protected]; De >> >> >> > Lara Guarch, Pablo <[email protected]> >> >> >> > Cc: [email protected]; [email protected]; [email protected] >> >> >> > 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.
