DPDK patches and discussions
 help / color / mirror / Atom feed
From: Ferruh Yigit <ferruh.yigit@intel.com>
To: Andrew Rybchenko <arybchenko@solarflare.com>,
	Viacheslav Ovsiienko <viacheslavo@mellanox.com>,
	dev@dpdk.org
Cc: matan@mellanox.com, rasland@mellanox.com, thomas@monjalon.net,
	jerinjacobk@gmail.com, stephen@networkplumber.org,
	ajit.khaparde@broadcom.com, maxime.coquelin@redhat.com,
	olivier.matz@6wind.com, david.marchand@redhat.com
Subject: Re: [dpdk-dev] [PATCH] doc: announce changes to ethdev rxconf structure
Date: Thu, 6 Aug 2020 17:15:48 +0100
Message-ID: <fc87c958-99ff-eef3-342c-5f336633d52c@intel.com> (raw)
In-Reply-To: <32d6e003-d4e7-06b0-39f3-f4a3ba2b6df6@solarflare.com>

On 8/3/2020 3:31 PM, Andrew Rybchenko wrote:
> On 8/3/20 1:58 PM, Viacheslav Ovsiienko wrote:
>> The DPDK datapath in the transmit direction is very flexible.
>> The applications can build multisegment packets and manages
>> almost all data aspects - the memory pools where segments
>> are allocated from, the segment lengths, the memory attributes
>> like external, registered, etc.
>>
>> In the receiving direction, the datapath is much less flexible,
>> the applications can only specify the memory pool to configure
>> the receiving queue and nothing more. In order to extend the
>> receiving datapath capabilities it is proposed to add the new
>> fields into rte_eth_rxconf structure:
>>
>> struct rte_eth_rxconf {
>>     ...
>>     uint16_t rx_split_num; /* number of segments to split */
>>     uint16_t *rx_split_len; /* array of segment lengthes */
>>     struct rte_mempool **mp; /* array of segment memory pools */
>>     ...
>> };
>>
>> The non-zero value of rx_split_num field configures the receiving
>> queue to split ingress packets into multiple segments to the mbufs
>> allocated from various memory pools according to the specified
>> lengths. The zero value of rx_split_num field provides the
>> backward compatibility and queue should be configured in a regular
>> way (with single/multiple mbufs of the same data buffer length
>> allocated from the single memory pool).
> 
> From the above description it is not 100% clear how it will
> coexist with:
>  - existing mb_pool argument of the rte_eth_rx_queue_setup()

+1

>  - DEV_RX_OFFLOAD_SCATTER
>  - DEV_RX_OFFLOAD_HEADER_SPLIT
> How will application know that the feature is supported? Limitations?

+1

> Is it always split by specified/fixed length?
> What happens if header length is actually different?

As far as I understand intention is to filter specific packets to a queue first
and later do the split, so the header length will be fixed...

> 
>> The new approach would allow splitting the ingress packets into
>> multiple parts pushed to the memory with different attributes.
>> For example, the packet headers can be pushed to the embedded data
>> buffers within mbufs and the application data into the external
>> buffers attached to mbufs allocated from the different memory
>> pools. The memory attributes for the split parts may differ
>> either - for example the application data may be pushed into
>> the external memory located on the dedicated physical device,
>> say GPU or NVMe. This would improve the DPDK receiving datapath
>> flexibility preserving compatibility with existing API.
>>
>> Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
>> ---
>>  doc/guides/rel_notes/deprecation.rst | 5 +++++
>>  1 file changed, 5 insertions(+)
>>
>> diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
>> index ea4cfa7..cd700ae 100644
>> --- a/doc/guides/rel_notes/deprecation.rst
>> +++ b/doc/guides/rel_notes/deprecation.rst
>> @@ -99,6 +99,11 @@ Deprecation Notices
>>    In 19.11 PMDs will still update the field even when the offload is not
>>    enabled.
>>  
>> +* ethdev: add new fields to ``rte_eth_rxconf`` to configure the receiving
>> +  queues to split ingress packets into multiple segments according to the
>> +  specified lengths into the buffers allocated from the specified
>> +  memory pools. The backward compatibility to existing API is preserved.
>> +
>>  * ethdev: ``rx_descriptor_done`` dev_ops and ``rte_eth_rx_descriptor_done``
>>    will be deprecated in 20.11 and will be removed in 21.11.
>>    Existing ``rte_eth_rx_descriptor_status`` and ``rte_eth_tx_descriptor_status``
> 


  reply	other threads:[~2020-08-06 16:15 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-03 10:58 Viacheslav Ovsiienko
2020-08-03 11:56 ` Jerin Jacob
2020-08-03 13:06   ` Slava Ovsiienko
2020-08-04 13:32     ` Jerin Jacob
2020-08-05  6:35       ` Slava Ovsiienko
2020-08-06 15:58       ` Ferruh Yigit
2020-08-06 16:25         ` Stephen Hemminger
2020-08-06 16:41           ` Jerin Jacob
2020-08-06 17:03           ` Slava Ovsiienko
2020-08-06 18:10             ` Stephen Hemminger
2020-08-07 11:23               ` Slava Ovsiienko
2020-08-03 14:31 ` [dpdk-dev] ***Spam*** " Andrew Rybchenko
2020-08-06 16:15   ` Ferruh Yigit [this message]
2020-08-06 16:29     ` [dpdk-dev] " Slava Ovsiienko
2020-08-06 16:37       ` Ferruh Yigit
2020-08-06 16:39         ` Slava Ovsiienko
2020-08-06 16:43           ` Ferruh Yigit
2020-08-06 16:48             ` Slava Ovsiienko
2020-08-05  8:49 ` [dpdk-dev] [PATCH v2] " Viacheslav Ovsiienko
2020-08-05 11:14   ` Andrew Rybchenko
2020-08-06 12:39     ` Thomas Monjalon
2020-08-06 21:42       ` Thomas Monjalon
2020-08-06 16:31   ` Ferruh Yigit
2020-08-06 17:00     ` Slava Ovsiienko
2020-08-06 16:55   ` [dpdk-dev] [PATCH v2] doc: fix the release notes for Mellanox PMD Viacheslav Ovsiienko
2020-08-06 17:12     ` Asaf Penso
2020-08-06 22:37       ` Thomas Monjalon
2020-08-03 15:18 [dpdk-dev] [PATCH] doc: announce changes to ethdev rxconf structure Slava Ovsiienko
2020-08-03 15:31 ` Andrew Rybchenko
2020-08-03 16:51   ` Slava Ovsiienko
2020-08-30 12:58     ` Andrew Rybchenko
2020-08-30 18:26       ` Stephen Hemminger
2020-08-31  6:35         ` Andrew Rybchenko
2020-08-31 16:59           ` Stephen Hemminger

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=fc87c958-99ff-eef3-342c-5f336633d52c@intel.com \
    --to=ferruh.yigit@intel.com \
    --cc=ajit.khaparde@broadcom.com \
    --cc=arybchenko@solarflare.com \
    --cc=david.marchand@redhat.com \
    --cc=dev@dpdk.org \
    --cc=jerinjacobk@gmail.com \
    --cc=matan@mellanox.com \
    --cc=maxime.coquelin@redhat.com \
    --cc=olivier.matz@6wind.com \
    --cc=rasland@mellanox.com \
    --cc=stephen@networkplumber.org \
    --cc=thomas@monjalon.net \
    --cc=viacheslavo@mellanox.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

DPDK patches and discussions

This inbox may be cloned and mirrored by anyone:

	git clone --mirror https://inbox.dpdk.org/dev/0 dev/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 dev dev/ https://inbox.dpdk.org/dev \
		dev@dpdk.org
	public-inbox-index dev

Example config snippet for mirrors.
Newsgroup available over NNTP:
	nntp://inbox.dpdk.org/inbox.dpdk.dev


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git