From: Chas Williams <3chas3@gmail.com>
To: mk@semihalf.com
Cc: Ferruh Yigit <ferruh.yigit@intel.com>,
mw@semihalf.com, gtzalik@amazon.com, evgenys@amazon.com,
dev@dpdk.org, matua@amazon.com, rk@semihalf.com
Subject: Re: [dpdk-dev] [PATCH v3 27/27] net/ena: set link speed as none
Date: Mon, 11 Jun 2018 12:15:09 -0400 [thread overview]
Message-ID: <CAG2-Gk=fxBefY_hONFspdkgZ=SG8Bk-f-qzThvT8+0o88gboNA@mail.gmail.com> (raw)
In-Reply-To: <CAJMMOfOdnHmhY+mJ3wwq0jxZ2vThdi03e0Yh_9tAHnmNG0KGBg@mail.gmail.com>
On Mon, Jun 11, 2018 at 4:01 AM Michał Krawczyk <mk@semihalf.com> wrote:
> 2018-06-10 3:35 GMT+02:00 Chas Williams <3chas3@gmail.com>:
> >
> >
> > On Fri, Jun 8, 2018 at 3:37 PM Ferruh Yigit <ferruh.yigit@intel.com>
> wrote:
> >>
> >> On 6/7/2018 10:43 AM, Michal Krawczyk wrote:
> >> > From: Rafal Kozik <rk@semihalf.com>
> >> >
> >> > Link speed should is not limited to 10Gb/s and it shouldn't be
> >> > hardcoded.
> >> >
> >> > They link speed is set to none instead and the applications shouldn't
> >> > rely on this value when using ENA PMD.
> >>
> >> Why not able to set link speed?
> >>
> >> And what is the link_autoneg, ETH_LINK_FIXED? What is the point of
> setting
> >> link
> >> speed FIXED and later speed value NONE?
> >
> >
> > The link speed is part of the spanning tree path computation. I don't
> think
> > picking 0 (or undefined)
> > is the appropriate choice. For virtual interfaces link speed is a
> > troublesome quantity but advertising
> > undefined seems worse then just use some constant value.
> >
>
> Setting constant value is not making much sense in the virtualized
> environment (ENA can be only used in the cloud). Link speed can be
> very flexible in that case and that's why ENA isn't providing it. If
> we will use constant value, what it should be? It may lead to
> confusion or can result in the performance issues because some
> applications are relying on this number to send max traffic.
>
What applications are using this value to determine the transmit speed?
> Applications should not make assumption that the link speed is always
> giving valid value and if it is not, they should try to configure rate
> dynamically, instead of statically.
So advertising a fixed speed of 10G should be perfectly fine. The
application should not assume 10G is a valid value and will attempt
to dynamically configure the rate.
The link speed should never be used to determine a transmit rate
for an application because you don't know the speeds in the middle
of the network.
>
> >>
> >>
> >> >
> >> > Fixes: 1173fca ("ena: add polling-mode driver")
> >>
> >> For next time can you please use git alias to have consistent Fixes
> format
> >>
> >> >
> >> > Signed-off-by: Rafal Kozik <rk@semihalf.com>
> >> > Acked-by: Michal Krawczyk <mk@semihalf.com>
> >> > ---
> >> > drivers/net/ena/ena_ethdev.c | 2 +-
> >> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >> >
> >> > diff --git a/drivers/net/ena/ena_ethdev.c
> b/drivers/net/ena/ena_ethdev.c
> >> > index 5c3b6494f..9ae73e331 100644
> >> > --- a/drivers/net/ena/ena_ethdev.c
> >> > +++ b/drivers/net/ena/ena_ethdev.c
> >> > @@ -848,7 +848,7 @@ static int ena_link_update(struct rte_eth_dev
> *dev,
> >> > adapter = (struct ena_adapter *)(dev->data->dev_private);
> >> >
> >> > link->link_status = adapter->link_status ? ETH_LINK_UP :
> >> > ETH_LINK_DOWN;
> >> > - link->link_speed = ETH_SPEED_NUM_10G;
> >> > + link->link_speed = ETH_SPEED_NUM_NONE;
> >> > link->link_duplex = ETH_LINK_FULL_DUPLEX;
> >> >
> >> > return 0;
> >> >
> >>
> >
>
next prev parent reply other threads:[~2018-06-11 16:15 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-07 9:42 [dpdk-dev] [PATCH v3 01/27] net/ena: change version number to 1.1.0 Michal Krawczyk
2018-06-07 9:42 ` [dpdk-dev] [PATCH v3 02/27] net/ena: update ena_com to the newer version Michal Krawczyk
2018-06-08 19:43 ` Ferruh Yigit
2018-06-11 9:54 ` [dpdk-dev] [PATCH v4 2/2] " Michal Krawczyk
2018-06-11 10:42 ` Ferruh Yigit
2018-06-11 11:01 ` [dpdk-dev] [PATCH v5 02/27] " Michal Krawczyk
2018-06-07 9:42 ` [dpdk-dev] [PATCH v3 03/27] net/ena: remove support of legacy LLQ Michal Krawczyk
2018-06-07 9:42 ` [dpdk-dev] [PATCH v3 04/27] net/ena: add interrupt handler for admin queue Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 05/27] net/ena: add stop and uninit routines Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 06/27] net/ena: add LSC intr support and AENQ handling Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 07/27] net/ena: handle ENA notification Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 08/27] net/ena: restart only initialized queues instead of all Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 09/27] net/ena: add reset routine Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 10/27] net/ena: add lrte_timer dependency for linking Michal Krawczyk
2018-06-08 19:17 ` Ferruh Yigit
2018-06-11 6:24 ` Michał Krawczyk
2018-06-17 22:37 ` Thomas Monjalon
2018-06-18 6:04 ` Michał Krawczyk
2018-06-18 8:30 ` Thomas Monjalon
2018-06-18 8:32 ` Michał Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 11/27] net/ena: add watchdog and keep alive AENQ handler Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 12/27] net/ena: add checking for admin queue state Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 13/27] net/ena: make watchdog configurable Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 14/27] net/ena: add RX out of order completion Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 15/27] net/ena: linearize Tx mbuf Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 16/27] net/ena: add info about max number of Tx/Rx descriptors Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 17/27] net/ena: unimplemented handler error Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 18/27] net/ena: rework configuration of IO queue numbers Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 19/27] net/ena: validate Tx req id Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 20/27] net/ena: add (un)likely statements Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 21/27] net/ena: adjust error checking and cleaning Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 22/27] net/ena: update numa node Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 23/27] net/ena: check pointer before memset Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 24/27] net/ena: change memory type Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 25/27] net/ena: fix GENMASK_ULL macro Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 26/27] net/ena: store handle after memory allocation Michal Krawczyk
2018-06-07 9:43 ` [dpdk-dev] [PATCH v3 27/27] net/ena: set link speed as none Michal Krawczyk
2018-06-08 19:37 ` Ferruh Yigit
2018-06-10 1:35 ` Chas Williams
2018-06-11 8:01 ` Michał Krawczyk
2018-06-11 16:15 ` Chas Williams [this message]
2018-06-19 6:32 ` Michał Krawczyk
2018-06-08 19:45 ` [dpdk-dev] [PATCH v3 01/27] net/ena: change version number to 1.1.0 Ferruh Yigit
2018-06-11 8:45 ` Michał Krawczyk
2018-06-11 9:26 ` Ferruh Yigit
2018-06-11 9:33 ` Michał Krawczyk
2018-06-11 9:50 ` Ferruh Yigit
2018-06-11 9:52 ` Michał Krawczyk
2018-06-11 12:34 ` Ferruh Yigit
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