DPDK patches and discussions
 help / color / mirror / Atom feed
From: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>
To: Chengchang Tang <tangchengchang@huawei.com>,
	"Yigit, Ferruh" <ferruh.yigit@intel.com>,
	"dev@dpdk.org" <dev@dpdk.org>
Cc: "linuxarm@huawei.com" <linuxarm@huawei.com>,
	"chas3@att.com" <chas3@att.com>,
	"humin29@huawei.com" <humin29@huawei.com>
Subject: Re: [dpdk-dev] [RFC 0/2] add Tx prepare support for bonding device
Date: Tue, 20 Apr 2021 08:33:23 +0000
Message-ID: <DM6PR11MB4491DA4721949C6D0D56F3729A489@DM6PR11MB4491.namprd11.prod.outlook.com> (raw)
In-Reply-To: <b68da1e1-e202-30db-4005-41d1cf6e6183@huawei.com>

Hi everyone,

> 
> On 2021/4/20 9:26, Ferruh Yigit wrote:
> > On 4/16/2021 12:04 PM, Chengchang Tang wrote:
> >> This patch add Tx prepare for bonding device.
> >>
> >> Currently, the bonding driver has not implemented the callback of
> >> rte_eth_tx_prepare function. Therefore, the TX prepare function of the
> >> slave devices will never be invoked. When hardware offloading such as
> >> CKSUM and TSO are enabled for some drivers, tx_prepare needs to be used
> >> to adjust packets (for example, set correct pseudo packet headers).
> >> Otherwise, related offloading fails and even packets are sent
> >> incorrectly. Due to this limitation, the bonded device cannot use these
> >> HW offloading in the Tx direction.
> >>
> >> Because packet sending algorithms are numerous and complex in bond PMD,
> >> it is hard to design the callback for rte_eth_tx_prepare. In this patch,
> >> the tx_prepare callback of bonding PMD is not implemented. Instead,
> >> rte_eth_tx_prepare has been called in tx_burst callback. And a global
> >> variable is introduced to control whether the bonded device need call
> >> the rte_eth_tx_prepare. If upper-layer users need to use some TX
> >> offloading that depend on tx_prepare , they should enable the preparation
> >> function. In this way, the bonded device will call the rte_eth_tx_prepare
> >> for the fast path packets in the tx_burst callback.

I admit that I didn't look at the implementation yet, but it sounds like 
overcomplication to me. Can't we just have a new TX function for bonding PMD
when TX offloads are enabled? And inside that function we will do:
tx_prepare(); tx_burst(); for selected device.
We can select this function at setup stage analysing requested by user TX offloads. 


> >>
> >
> > What do you think to add a devarg to bonding PMD to control the tx_prepare?
> > It won't be as dynamic as API, since it can be possible to change the behavior after application is started with API, but do we really need
> this?
> 
> If an API is not added, unnecessary constraints may be introduced. If the
> bonding device is created through the rte_eth_bond_create interface instead
> devarg "vdev", this function cannot be used because devargs does not take effect
> in this case. But from an ease-of-use perspective, adding a devarg is a good
> idea. I will add related implementations in the later official patches.

I am also against introducing new devarg to control tx_prepare() invocation.
I think at dev_config/queue_setup phase PMD will have enough information to decide.

> 
> If I understand correctly, the current community does not want to introduce
> more private APIs for PMDs. However, the absence of an API on this issue would
> introduce some unnecessary constraints, and from that point of view, I think
> adding an API seems necessary.
> >
> >> Chengchang Tang (2):
> >>    net/bonding: add Tx prepare for bonding
> >>    app/testpmd: add cmd for bonding Tx prepare
> >>
> >>   app/test-pmd/cmdline.c                      | 66 +++++++++++++++++++++++++++++
> >>   doc/guides/testpmd_app_ug/testpmd_funcs.rst |  9 ++++
> >>   drivers/net/bonding/eth_bond_private.h      |  1 +
> >>   drivers/net/bonding/rte_eth_bond.h          | 29 +++++++++++++
> >>   drivers/net/bonding/rte_eth_bond_api.c      | 28 ++++++++++++
> >>   drivers/net/bonding/rte_eth_bond_pmd.c      | 33 +++++++++++++--
> >>   drivers/net/bonding/version.map             |  5 +++
> >>   7 files changed, 167 insertions(+), 4 deletions(-)
> >>
> >> --
> >> 2.7.4
> >>
> >
> >
> > .
> >


  reply	other threads:[~2021-04-20  8:33 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-16 11:04 Chengchang Tang
2021-04-16 11:04 ` [dpdk-dev] [RFC 1/2] net/bonding: add Tx prepare for bonding Chengchang Tang
2021-04-16 11:04 ` [dpdk-dev] [RFC 2/2] app/testpmd: add cmd for bonding Tx prepare Chengchang Tang
2021-04-16 11:12 ` [dpdk-dev] [RFC 0/2] add Tx prepare support for bonding device Min Hu (Connor)
2021-04-20  1:26 ` Ferruh Yigit
2021-04-20  2:44   ` Chengchang Tang
2021-04-20  8:33     ` Ananyev, Konstantin [this message]
2021-04-20 12:44       ` Chengchang Tang
2021-04-20 13:18         ` Ananyev, Konstantin
2021-04-20 14:06           ` Chengchang Tang
2021-04-23  9:46 ` [dpdk-dev] [PATCH " Chengchang Tang
2021-04-23  9:46   ` [dpdk-dev] [PATCH 1/2] net/bonding: support Tx prepare for bonding Chengchang Tang
2021-06-08  9:49     ` Andrew Rybchenko
2021-06-09  6:42       ` Chengchang Tang
2021-06-09  9:35         ` Andrew Rybchenko
2021-06-10  7:32           ` Chengchang Tang
2021-06-14 14:16             ` Andrew Rybchenko
2021-06-09 10:25         ` Ananyev, Konstantin
2021-06-10  6:46           ` Chengchang Tang
2021-06-14 11:36             ` Ananyev, Konstantin
2021-04-23  9:46   ` [dpdk-dev] [PATCH 2/2] net/bonding: support configuring Tx offloading " Chengchang Tang
2021-06-08  9:49     ` Andrew Rybchenko
2021-06-09  6:57       ` Chengchang Tang
2021-06-09  9:11         ` Ananyev, Konstantin
2021-06-09  9:37           ` Andrew Rybchenko
2021-06-10  6:29             ` Chengchang Tang
2021-06-14 11:05               ` Ananyev, Konstantin
2021-06-14 14:13                 ` Andrew Rybchenko
2021-04-30  6:26   ` [dpdk-dev] [PATCH 0/2] add Tx prepare support for bonding device Chengchang Tang
2021-04-30  6:47     ` Min Hu (Connor)
2021-06-03  1:44   ` Chengchang Tang

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=DM6PR11MB4491DA4721949C6D0D56F3729A489@DM6PR11MB4491.namprd11.prod.outlook.com \
    --to=konstantin.ananyev@intel.com \
    --cc=chas3@att.com \
    --cc=dev@dpdk.org \
    --cc=ferruh.yigit@intel.com \
    --cc=humin29@huawei.com \
    --cc=linuxarm@huawei.com \
    --cc=tangchengchang@huawei.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