Re: [dpdk-dev] [PATCH v1 2/6] compress/zlib: add device setup PMD ops

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

HI Lee

>-----Original Message-----
>From: Daly, Lee [mailto:lee.daly@intel.com]
>Sent: 25 June 2018 15:35
>To: Verma, Shally <Shally.Verma@cavium.com>
>Cc: Trahe, Fiona <fiona.trahe@intel.com>; dev@dpdk.org; pathreay@caviumnetworks.com; Sahu, Sunila <Sunila.Sahu@cavium.com>;
>Gupta, Ashish <Ashish.Gupta@cavium.com>; De Lara Guarch, Pablo <pablo.de.lara.guarch@intel.com>
>Subject: RE: [dpdk-dev] [PATCH v1 2/6] compress/zlib: add device setup PMD ops
>
//snip

>> >>+static const struct rte_compressdev_capabilities zlib_pmd_capabilities[]
>> = {
>> >>+      {   /* Deflate */
>> >>+              .algo = RTE_COMP_ALGO_DEFLATE,
>> >>+              .comp_feature_flags =
>> RTE_COMP_FF_SHAREABLE_PRIV_XFORM,
>> >[Lee] The priv_xform structure in this case is not shareable, as it
>> >contains your zlib_stream structure, which contains zlibs own zstream
>> >struct. This is not read only, the contents of this zstream will be written to,
>> which means it is not shareable across queue pairs or devices.
>> >
>> [Shally] Per my understanding, SHAREABLE_PRIV_XFORM here means xform
>> is shareable by all ops in one single enqueue_burst() but not across devices
>> or qps by multiple threads in parallel. Does your implementation support
>> such usage of shareable priv_xforms?
>>
>> Thanks for review.
>> Shally
>[Lee]
>Hey Shally, I have just clarified this with Fiona and Pablo and the intended use of Shareable priv xforms is to allow a xform to be shared
>across devices & qps not just all the ops in a burst, yes the ISA-L PMD has a shareable private xform due to all its contents being read
>only.
>
[Shally] Ok. Got that. Will change it accordingly.

Thanks
Shally

>>
>> >>+              .window_size = {
>> >>+                      .min = 8,
>> >>+                      .max = 15,
>> >>+                      .increment = 2
>> >>+              },
>> >>+      },
>> >>+
>> >>+      RTE_COMP_END_OF_CAPABILITIES_LIST()
>> >>+