Re: CVS commit: src/sys/dev/usb

[sc dying <sc.dying%gmail.com@localhost>]

On Fri, Jun 28, 2019 at 1:57 AM matthew green <mrg%netbsd.org@localhost> wrote:
>
> Module Name:    src
> Committed By:   mrg
> Date:           Fri Jun 28 01:57:43 UTC 2019
>
> Modified Files:
>         src/sys/dev/usb: if_axen.c if_cdce.c if_ure.c
>
> Log Message:
> more smp cleanup for ure(4)/axen(4)/cdce(4):

Thank you for working!

> - convert IFF_ALLMULTI to ETHER_F_ALLMULTI, using ETHER_LOCK()
> - remove IFF_OACTIVE use, and simply check the ring count in start

cdce_start_locked() has the last one.

> - assert/take more locks
> - XXX: IFF_RUNNING is not properly protected (all driver problem)
> - fix axen_timer setting so it actually runs
> - document a locking issue in stop callback:
>   stop is called with the softc lock held, but the lock order
>   in all other places is ifnet -> softc -> rx -> tx, so taking
>   ifnet lock when softc lock is held would be problematic

ure_init_locked() calls ure_stop() with sc->ure_lock held,
so it would cause 'locking against myself' perhaps when
ifconfig such as IFF_DEBUG while the interface is up.

> - in rxeof check for stopping/dying more often.  i managed to
>   trigger a pagefault in cdce_rxeof() when yanking an active
>   device as it attempted to usbd_setup_xfer() on closed pipes.
> - add missing USBD_MPSAFE and cdce_stopping resetting for cdce(4)
>
> between this and other recent clean ups increase performance of
> these drivers mostly.  some numbers (in mbit/sec):
>
>         old:                            new:
> driver  in      out     in+out          in      out     in+out
> ----    --      ---     ------          --      ---     ------
> cdce    39      32      44              38      33      54
> axen    44      34      45              48      37      42
> ure     36      34      35              36      38      38
>
> i'm not sure why axen drops a little with in+out.  cdce is
> helped quite a lot, and ure a little.  it is disappointing that
> ure does not outperform cdce -- it's the same actual hardware,
> and the device-specific (ure) should outperform the generic
> cdce driver...
>
>
> To generate a diff of this commit:
> cvs rdiff -u -r1.48 -r1.49 src/sys/dev/usb/if_axen.c
> cvs rdiff -u -r1.50 -r1.51 src/sys/dev/usb/if_cdce.c
> cvs rdiff -u -r1.12 -r1.13 src/sys/dev/usb/if_ure.c
>
> Please note that diffs are not public domain; they are subject to the
> copyright notices on the relevant files.
>