>-----Original Message-----
>From: De Lara Guarch, Pablo <pablo.de.lara.gua...@intel.com>
>Sent: 24 July 2018 13:24
>To: Verma, Shally <shally.ve...@cavium.com>
>Cc: dev@dpdk.org; Athreya, Narayana Prasad
><narayanaprasad.athr...@cavium.com>; Challa, Mahipal
><mahipal.cha...@cavium.com>; Sahu, Sunila <sunila.s...@cavium.com>; Sahu,
>Sunila <sunila.s...@cavium.com>; Gupta, Ashish
><ashish.gu...@cavium.com>
>Subject: RE: [PATCH v4 4/5] compress/zlib: support burst enqueue/dequeue
>
>External Email
>
>> -----Original Message-----
>> From: Verma, Shally [mailto:shally.ve...@cavium.com]
>> Sent: Tuesday, July 24, 2018 8:45 AM
>> To: De Lara Guarch, Pablo <pablo.de.lara.gua...@intel.com>
>> Cc: dev@dpdk.org; Athreya, Narayana Prasad
>> <narayanaprasad.athr...@cavium.com>; Challa, Mahipal
>> <mahipal.cha...@cavium.com>; Sahu, Sunila <sunila.s...@cavium.com>; Sahu,
>> Sunila <sunila.s...@cavium.com>; Gupta, Ashish <ashish.gu...@cavium.com>
>> Subject: RE: [PATCH v4 4/5] compress/zlib: support burst enqueue/dequeue
>>
>>
>>
>> >-----Original Message-----
>> >From: De Lara Guarch, Pablo <pablo.de.lara.gua...@intel.com>
>> >Sent: 24 July 2018 03:55
>> >To: Verma, Shally <shally.ve...@cavium.com>
>> >Cc: dev@dpdk.org; Athreya, Narayana Prasad
>> ><narayanaprasad.athr...@cavium.com>; Challa, Mahipal
>> ><mahipal.cha...@cavium.com>; Sahu, Sunila <sunila.s...@cavium.com>;
>> >Sahu, Sunila <sunila.s...@cavium.com>; Gupta, Ashish
>> ><ashish.gu...@cavium.com>
>> >Subject: RE: [PATCH v4 4/5] compress/zlib: support burst
>> >enqueue/dequeue
>> >
>> >External Email
>> >
>> >> -----Original Message-----
>> >> From: Shally Verma [mailto:shally.ve...@caviumnetworks.com]
>> >> Sent: Monday, July 23, 2018 3:51 PM
>> >> To: De Lara Guarch, Pablo <pablo.de.lara.gua...@intel.com>
>> >> Cc: dev@dpdk.org; pathr...@caviumnetworks.com;
>> >> mcha...@caviumnetworks.com; Sunila Sahu <ss...@caviumnetworks.com>;
>> >> Sunila Sahu <sunila.s...@caviumnetworks.com>; Ashish Gupta
>> >> <ashish.gu...@caviumnetworks.com>
>> >> Subject: [PATCH v4 4/5] compress/zlib: support burst enqueue/dequeue
>> >>
>> >> From: Sunila Sahu <ss...@caviumnetworks.com>
>> >>
>> >> Signed-off-by: Sunila Sahu <sunila.s...@caviumnetworks.com>
>> >> Signed-off-by: Shally Verma <shally.ve...@caviumnetworks.com>
>> >> Signed-off-by: Ashish Gupta <ashish.gu...@caviumnetworks.com>
>> >> ---
>> >> drivers/compress/zlib/zlib_pmd.c | 255
>> >> ++++++++++++++++++++++++++++++++++++++-
>> >> 1 file changed, 254 insertions(+), 1 deletion(-)
>> >>
>> >> diff --git a/drivers/compress/zlib/zlib_pmd.c
>> >> b/drivers/compress/zlib/zlib_pmd.c
>> >> index 47bc73d..dc1e230 100644
>> >> --- a/drivers/compress/zlib/zlib_pmd.c
>> >> +++ b/drivers/compress/zlib/zlib_pmd.c
>> >> @@ -7,7 +7,214 @@
>> >>
>> >> #include "zlib_pmd_private.h"
>> >>
>> >> -/** Parse comp xform and set private xform/stream parameters */
>> >> +/** Compute next mbuf in the list, assign data buffer and length,
>> >> + * returns 0 if mbuf is NULL
>> >> + */
>> >> +#define COMPUTE_BUF(mbuf, data, len) \
>> >> + ((mbuf = mbuf->next) ? \
>> >> + (data = rte_pktmbuf_mtod(mbuf, uint8_t *)), \
>> >> + (len = rte_pktmbuf_data_len(mbuf)) : 0)
>> >> +
>> >> +static void
>> >> +process_zlib_deflate(struct rte_comp_op *op, z_stream *strm) {
>> >
>> >...
>> >
>> >> + /* Update z_stream with the inputs provided by application */
>> >> + strm->next_in = rte_pktmbuf_mtod_offset(mbuf_src, uint8_t *,
>> >> + op->src.offset);
>> >
>> >This is assuming that src buffer is a linear buffer or that offset won't be
>> >large
>> enough to cross boundaries between segments.
>> >If an SGL is passed and offset is bigger than the first segment,
>> >next_in should point at a different segment, with the remaining part of
>> >the offset in that segment (look at ISA-L SGL patch:
>> http://patches.dpdk.org/patch/43283/). Same applies to avail_in, next_out and
>> avail_out.
>>
>> [Shally] as per my last knowledge, offset was expected to be belonging only
>> to
>> the first segment in chained mbuf. Isn't that the case anymore? Did I miss
>> any
>> update on its definition?
>> We had added the logic earlier that you're suggesting but removed that
>> later, as
>> I understood clarification about offset falling into any segment is still
>> pending.
>>
>
>According to the comments:
>
> uint32_t offset;
> /**< Starting point for compression or decompression,
> * specified as number of bytes from start of packet in
> * source buffer.
> * This offset starts from the first segment
> * of the buffer, in case the m_src is a chain of mbufs.
>
>It says that the offset starts from the first segment, but not that
>it is only applicable for the first segment.
>From my point of view, an SGL should be seen like a contiguous (linear) buffer,
>so if the offset crosses multiple segments, it is still valid, as it is still
>part of the buffer.
>
Also believe doc need an update, it's kind of misleading "start from first
segment", should replace by "in case of chained mbuf, it can fall into any
segments".
Thanks
Shally
>Thanks,
>Pablo
>
>> Thanks
>> Shally
