On 29.08.2021 22:14:41, Oliver Hartkopp wrote:
> > > IMO the issue arises with the use of isotpsend and isotprecv.
> > > These tools are intended to get a hands-on impression how the isotp
> > > stack works.
> > > 
> > > This kind of use in a script leads to the creation and (now delayed)
> > > *removal* of isotp sockets for *each* single PDU transfer.
> > 
> > Maybe I am wrong but I see something different.
> > e.g. without this patch:
> >   (000.000240)  canfd0  714   [8]  2B 01 01 01 01 01 01 01
> >   (000.000261)  canfd0  77E   [8]  30 0F 00 AA AA AA AA AA
> >   (000.000496)  canfd0  714   [8]  2C 01 01 01 01 01 01 01
> > 
> > and with this patch:
> >   (000.000414)  canfd0  714   [8]  2B 01 01 01 01 01 01 01
> >   (000.000262)  canfd0  77E   [8]  30 0F 00 AA AA AA AA AA
> >   (000.001536)  canfd0  714   [8]  2C 01 01 01 01 01 01 01
> > 
> 
> I'm running a 5.14.0-rc7-00011-g6e764bcd1cf7 kernel here and see this:
> 
>  (000.000001)  vcan0  714   [8]  2B 01 01 01 01 01 01 01
>  (000.000015)  vcan0  77E   [8]  30 0F 00 AA AA AA AA AA
>  (000.000005)  vcan0  714   [8]  2C 01 01 01 01 01 01 01
> 
> Test iso-tp with 1000 byte frames on vcan0 (data:01)
>     1 / curr:   40 / min:   40 / max:   40 / avg:   40.0
>     2 / curr:   30 / min:   30 / max:   40 / avg:   35.0
>     3 / curr:   35 / min:   30 / max:   40 / avg:   35.0
>     4 / curr:   52 / min:   30 / max:   52 / avg:   39.2
>     5 / curr:   40 / min:   30 / max:   52 / avg:   39.4
> (..)
> 
> when running your scripts from the initial post.
> 
> Is you canfd0 interface a real hardware?

I can reproduce the issue here, on an embedded system with a real
hardware CAN interface.

In j1939 we make use of rcu so that we don't need the synchronize_net().
Is it possible to use this is ISOTP, too?

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
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