[dpdk-dev] Survey for final decision about per-port offload API

Xing, Beilei beilei.xing at intel.com
Mon Apr 2 05:18:48 CEST 2018



> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas at monjalon.net]
> Sent: Friday, March 30, 2018 9:48 PM
> To: dev at dpdk.org
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> Wenzhuo <wenzhuo.lu at intel.com>; Ananyev, Konstantin
> <konstantin.ananyev at intel.com>; Xing, Beilei <beilei.xing at intel.com>;
> Zhang, Qi Z <qi.z.zhang at intel.com>; Wu, Jingjing <jingjing.wu at intel.com>;
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> Olivier Matz <olivier.matz at 6wind.com>
> Subject: Survey for final decision about per-port offload API
> 
> There are some discussions about a specific part of the offload API:
> 	"To enable per-port offload, the offload should be set on both
> 	device configuration and queue setup."
> 
> It means the application must repeat the port offload flags in
> rte_eth_conf.[rt]xmode.offloads and rte_eth_[rt]xconf.offloads, when calling
> respectively rte_eth_dev_configure() and rte_eth_[rt]x_queue_setup for
> each queue.
> 
> The PMD must check if there is mismatch, i.e. a port offload not repeated in
> queue setup.
> There is a proposal to do this check at ethdev level:
> 	http://dpdk.org/ml/archives/dev/2018-March/094023.html
> 
> It was also proposed to relax the API and allow "forgetting" port offloads in
> queue offloads:
> 	http://dpdk.org/ml/archives/dev/2018-March/092978.html
> 
> It would mean the offloads applied to a queue result of OR operation:
> 	rte_eth_conf.[rt]xmode.offloads | rte_eth_[rt]xconf.offloads
> 
> 1/ Do you agree with above API change?
Yes.

> 
> 
> If we agree with this change, we need to update the documentation and
> remove the checks in PMDs.
> Note: no matter what is decided here, 18.05-rc1 should have all PMDs
> switched to the API which was defined in 17.11.
> Given that API is new and not yet adopted by the applications, the sonner it
> is fixed, the better.
> 
> 2/ Should we do this change in 18.05-rc2?
Yes.

> 
> 
> At the same time, we want to make clear that an offload enabled at port
> level, cannot be disabled at queue level.
> 
> 3/ Do you agree with above statement (to be added in the doc)?
Yes.

> 
> 
> There is the same kind of confusion in the offload capabilities:
> 	rte_eth_dev_info.[rt]x_offload_capa
> 	rte_eth_dev_info.[rt]x_queue_offload_capa
> The queue capabilities must be a subset of port capabilities, i.e. every queue
> capabilities must be reported as port capabilities.
> But the port capabilities should be reported at queue level only if it can be
> applied to a specific queue.
> 
> 4/ Do you agree with above statement (to be added in the doc)?
Yes.

> 
> 
> Please give your opinion on questions 1, 2, 3 and 4.
> Answering by yes/no may be sufficient in most cases :) Thank you
> 



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