Re: [PATCH V4 0/5] app/testpmd: support mulitple process attach and detach port

[Thomas Monjalon <thomas@monjalon.net>]

19/01/2023 11:31, lihuisong (C):
> 在 2023/1/18 22:12, Thomas Monjalon 写道:
> > 11/01/2023 11:46, Ferruh Yigit:
> >> On 1/11/2023 10:27 AM, Ferruh Yigit wrote:
> >>> On 1/11/2023 12:53 AM, lihuisong (C) wrote:
> >>>> 在 2023/1/11 0:51, Ferruh Yigit 写道:
> >>>>> Hi Huisong,
> >>>>>
> >>>>> I haven't checked the patch in detail yet, but I can see it gives some
> >>>>> ABI compatibility warnings, is this expected:
> >>>> This is to be expected. Because we insert a device state,
> >>>> RTE_ETH_DEV_ALLOCATED,
> >>>> before RTE_ETH_DEV_ATTACHED for resolving the issue patch 2/5 mentioned.
> >>>> We may have to announce it. What do you think?
> >>> If there is an actual ABI break, it can't go in this release, need to
> >>> wait LTS release and yes needs deprecation notice in advance.
> >>>
> >>> But not all enum value change warnings are real break, need to
> >>> investigate all warnings one by one.
> >>> Need to investigate if old application & new dpdk library may cause any
> >>> unexpected behavior for application.
> >>>
> >> OR, appending new enum item, `RTE_ETH_DEV_ALLOCATED`, to the end of the
> >> enum solves the issue, although logically it won't look nice.
> >> Perhaps order can be fixed in next LTS, to have more logical order, but
> >> not quite sure if order worth the disturbance may cause in application.
> > It is a state with a logical order, so it would be nice to be able to do
> > if (state > RTE_ETH_DEV_ALLOCATED)
> > but given there is RTE_ETH_DEV_REMOVED later in the enum, not sure it is useful.
> 
> The device state is internel. Applications should not access it 
> directly, right?

Right

> Currently, ethdev layer or PMD use it by enum value instead of the way like
> 'state > RTE_ETH_DEV_ALLOCATED'.

Right

> But, I encapsulated an API, rte_eth_dev_is_used(), for ethdev or PMD to 
> call.
> I'm not sure if it can help to eliminate our concerns.

Yes I think it's OK.