Messages in this thread |  | | Date | Sat, 04 Nov 2000 10:36:36 -0500 | From | Jeff Garzik <> | Subject | Re: Locking Between User Context and Soft IRQs in 2.4.0 |
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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[1] > > > > > > NOTE [1]: 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
-- 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 majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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