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Cc: arch@FreeBSD.org, net@FreeBSD.org, freebsd-arch@FreeBSD.org,
	Hans Petter Selasky <hselasky@c2i.net>
Subject: Re: Changes in the network interface queueing handoff model
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Robert Watson writes:
 > tear-down magic.  What Solaris does here, FYI, is basically add a lock around 
 > entering the device driver via their mac layer in order to prevent it from 
 > "disappearing" while in use via the ifnet interface.  I'm not sure if we want 

At least for GLDv2, this is a reader-writer lock.  The transmit and
receive paths take a read lock on the device's macinfo (like ifnet)
struct, and the detach code takes a write lock.  The Solaris driver
model does not serialize transmits (or receives), as one might think
from reading the above.


Drew