[PATCH v4 3/3] ring: add telemetry cmd for ring info

[David Marchand]

On Tue, Jul 4, 2023 at 4:11 PM Thomas Monjalon <thomas at monjalon.net> wrote:
>
> 04/07/2023 10:04, Jie Hai:
> > On 2023/6/20 22:34, Thomas Monjalon wrote:
> > > 20/06/2023 10:14, Jie Hai:
> > >> On 2023/2/20 20:55, David Marchand wrote:
> > >>> On Fri, Feb 10, 2023 at 3:50 AM Jie Hai <haijie1 at huawei.com> wrote:
> > >>>>
> > >>>> This patch supports dump of ring information by its name.
> > >>>> An example using this command is shown below:
> > >>>>
> > >>>> --> /ring/info,MP_mb_pool_0
> > >>>> {
> > >>>>     "/ring/info": {
> > >>>>       "name": "MP_mb_pool_0",
> > >>>>       "socket": 0,
> > >>>>       "flags": "0x0",
> > >>>>       "producer_type": "MP",
> > >>>>       "consumer_type": "MC",
> > >>>>       "size": 262144,
> > >>>>       "mask": "0x3ffff",
> > >>>>       "capacity": 262143,
> > >>>>       "used_count": 153197,
> > >>>>       "consumer_tail": 2259,
> > >>>>       "consumer_head": 2259,
> > >>>>       "producer_tail": 155456,
> > >>>>       "producer_head": 155456,
> > >>>
> > >>> What would an external user make of such an information?
> > >>>
> > >>> I'd like to have a better idea what your usecase is.
> > >>> If it is for debugging, well, gdb is probably a better candidate.
> > >>>
> > >>>
> > >> Hi David,
> > >> Thanks for your question and I'm sorry for getting back to you so late.
> > >> There was a problem with my mailbox and I lost all my mails.
> > >>
> > >> The ring information exported by telemetry can be used to check the ring
> > >> status periodically during normal use. When an error occurs, the fault
> > >> cause can be deduced based on the information.
> > >> GDB is more suitable for locating errors only when they are sure that
> > >> errors will occur.
> > >
> > > Yes, when an error occurs, you can use GDB,
> > > and you don't need all these internal values in telemetry.
> > >
> > >
> > Hi, David, Thomas,
> >
> > Would it be better to delete the last four items?
> >         "consumer_tail": 2259,
> >         "consumer_head": 2259,
> >         "producer_tail": 155456,
> >         "producer_head": 155456,
>
> Yes it would be better.
> David, other maintainers, would it make the telemetry command a good idea?
>
>

Without the ring head/tail exposed, it seems ok.
It still exposes the ring flags which are kind of internal things, but
those are parts of the API/ABI, iiuc, so it should not be an issue.


-- 
David Marchand