linux/include
John Fastabend 314b4778ed net: dcbnl, add multicast group for DCB
Now that dcbnl is being used in many cases by more
than a single agent it is beneficial to be notified
when some entity either driver or user space has
changed the DCB attributes.

Today applications either end up polling the interface
or relying on a user space database to maintain the DCB
state and post events. Polling is a poor solution for
obvious reasons. And relying on a user space database
has its own downside. Namely it has created strange
boot dependencies requiring the database be populated
before any applications dependent on DCB attributes
starts or the application goes into a polling loop.
Populating the database requires negotiating link
setting with the peer and can take anywhere from less
than a second up to a few seconds depending on the switch
implementation.

Perhaps more importantly if another application or an
embedded agent sets a DCB link attribute the database
has no way of knowing other than polling the kernel.
This prevents applications from responding quickly to
changes in link events which at least in the FCoE case
and probably any other protocols expecting a lossless
link may result in IO errors.

By adding a multicast group for DCB we have clean way
to disseminate kernel DCB link attributes up to user
space. Avoiding the need for user space to maintain
a coherant database and disperse events that potentially
do not reflect the current link state.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-21 16:06:11 -07:00
..
acpi Merge branches 'acpica', 'aml-custom', 'bugzilla-16548', 'bugzilla-20242', 'd3-cold', 'ec-asus' and 'thermal-fix' into release 2011-05-29 04:38:48 -04:00
asm-generic Merge branches 'gpio/merge' and 'spi/merge' of git://git.secretlab.ca/git/linux-2.6 2011-06-17 10:36:32 -07:00
crypto
drm drm/radeon: workaround a hw bug on some radeon chipsets with all-0 EDIDs. 2011-06-16 16:30:54 +10:00
keys
linux net: dcbnl, add multicast group for DCB 2011-06-21 16:06:11 -07:00
math-emu
media [media] v4l: Fix media_entity_to_video_device macro argument name 2011-06-01 09:42:03 -03:00
mtd
net net: dcbnl, add multicast group for DCB 2011-06-21 16:06:11 -07:00
pcmcia
rdma Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband 2011-05-26 12:13:57 -07:00
rxrpc
scsi [SCSI] libsas: Add option for SATA soft reset 2011-05-26 22:49:33 -05:00
sound
target
trace core: add tracepoints for queueing skb to rcvbuf 2011-06-21 16:06:10 -07:00
video
xen Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/djm/tmem 2011-05-26 10:50:56 -07:00
Kbuild