On 8/6/19 6:45 PM, Stephen Hemminger wrote:
On Tue, 6 Aug 2019 14:31:43 +0000
Pavan Nikhilesh Bhagavatula <[email protected]> wrote:
-----Original Message-----
From: Andrew Rybchenko <[email protected]>
Sent: Tuesday, August 6, 2019 2:30 PM
To: Pavan Nikhilesh Bhagavatula <[email protected]>; Jerin
Jacob Kollanukkaran <[email protected]>; John McNamara
<[email protected]>; Marko Kovacevic
<[email protected]>; Thomas Monjalon
<[email protected]>; Ferruh Yigit <[email protected]>
Cc: [email protected]
Subject: [EXT] Re: [dpdk-dev] [RFC 1/3] ethdev: add ptype as an Rx
offload
External Email
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On 8/6/19 11:02 AM, [email protected] wrote:
From: Pavan Nikhilesh <[email protected]>
Add ptype to DEV_RX_OFFLOAD_* flags which can be used to
enable/disable
packet type parsing.
Signed-off-by: Pavan Nikhilesh <[email protected]>
I like the idea. I think there are few more Rx features which
lack Rx offload bit:
- delivery of RSS hash in mbuf (it is not always required when
RSS is used to distribute packets across Rx queues)
Especially when applications use custom hash functions to store flows.
- maybe Rx mark, since it is an extra information which could
be passed by NIC to CPU and it is better to know in advance
at Rx queue setup if it should be requested and processed
Are you referring to RTE_FLOW_ACTION_TYPE_MARK?
API breakage should be considered here. I think it is OK to
introduce it in the next release cycle in a dummy way which
does not affect packet type delivery for existing PMDs
(i.e. add offload capability and advertise in PMD, but do not
take it into account when Rx mbuf is filled in) and
submit deprecation notice that it may be taken into account
by PMDs in 20.02 to avoid packet type delivery if the offload
is not requested. It will allow applications to make transition
smoother.
Couldn’t agree with you more. I could extend the current RFC to include
RSS and RX mark as we would be modifying the same offload fields across
all drivers. Easier for PMD maintainers too.
Acked-by: Andrew Rybchenko <[email protected]>
I would rather the ptype offload be always on and handled in software
for drivers that don't do it.
It sounds like wasting of CPU cycle for nothing in some cases.
Also where should software stop? There are various tunnels etc.
If application is unhappy with supported classification provided
by the driver, it can always use software parser if really required.
