Andi Kleen wrote:
> On Sat, Nov 04, 2000 at 04:45:33AM -0500, Jeff Garzik wrote:
> > > * What about dev->open and dev->stop ?
> > Sleep all you want, we'll leave the light on for ya.
> ... but make sure you have no module unload races (or at least not too
> huge holes, some are probably unavoidable with the current network
> driver interface, e.g. without moving module count management a bit up).
> This means you should do MOD_INC_USE_COUNT very early at least to
> minimize the windows (and DEC_USE_COUNT very late)
Can you provide a trace of a race or deadlock? I do not see where there
are races in the current 2.4.x code.
> > dev->do_ioctl:
> > Locking: Inside rtnl_lock() semaphore.
> > Sleeping: OK
> Just make sure you lock against your interrupt and xmit threads.
But of course :) My doc only covered locks external to the driver.
> > Locking: Inside dev->xmit_lock spinlock.
> > Sleeping: NO
> > NOTE : On principle, you should not sleep when a spinlock is held.
> > However, since this spinlock is per-net-device, we only block ourselves
> > if we sleep, so the effect is mitigated.
> Sounds like dangerous advice.
Probably... I changed the doc "just say no" :)
-- Jeff Garzik | Dinner is ready when Building 1024 | the smoke alarm goes off. MandrakeSoft | -/usr/games/fortune - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to email@example.com Please read the FAQ at http://www.tux.org/lkml/
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