CVS commit: [netbsd-6] src/sys/arch/xen/xen

["Jeff Rizzo" <riz%netbsd.org@localhost>]

Module Name:    src
Committed By:   riz
Date:           Thu Feb 23 02:30:16 UTC 2012

Modified Files:
        src/sys/arch/xen/xen [netbsd-6]: if_xennet_xenbus.c

Log Message:
Pull up following revision(s) (requested by bouyer in ticket #33):
        sys/arch/xen/xen/if_xennet_xenbus.c: revision 1.59
Allocating a fixed, limited number of buffers for receive and sending them
to the network stack is a bad idea, because if all receive buffers sits
in socket queues, the interface receive stalls by lack of buffers.
Instead, get receive pages from a pool_cache(9). Copying to a mbuf cluser
would work too, but testings shows this has an important performance hit.
This also simplifies locking.
While there, notify the dom0 when we add some receive buffers (older
linux dom0 didn't care, but newer one do).
Problem reported and fix tested by Brian Marcotte on port-xen


To generate a diff of this commit:
cvs rdiff -u -r1.58 -r1.58.2.1 src/sys/arch/xen/xen/if_xennet_xenbus.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.