linux/include/uapi
Jesper Dangaard Brouer c06ab09127 net_sched: restore "linklayer atm" handling
[ Upstream commit 8a8e3d84b1 ]

commit 56b765b79 ("htb: improved accuracy at high rates")
broke the "linklayer atm" handling.

 tc class add ... htb rate X ceil Y linklayer atm

The linklayer setting is implemented by modifying the rate table
which is send to the kernel.  No direct parameter were
transferred to the kernel indicating the linklayer setting.

The commit 56b765b79 ("htb: improved accuracy at high rates")
removed the use of the rate table system.

To keep compatible with older iproute2 utils, this patch detects
the linklayer by parsing the rate table.  It also supports future
versions of iproute2 to send this linklayer parameter to the
kernel directly. This is done by using the __reserved field in
struct tc_ratespec, to convey the choosen linklayer option, but
only using the lower 4 bits of this field.

Linklayer detection is limited to speeds below 100Mbit/s, because
at high rates the rtab is gets too inaccurate, so bad that
several fields contain the same values, this resembling the ATM
detect.  Fields even start to contain "0" time to send, e.g. at
1000Mbit/s sending a 96 bytes packet cost "0", thus the rtab have
been more broken than we first realized.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-14 06:54:55 -07:00
..
asm-generic net: add option to enable error queue packets waking select 2013-03-31 19:44:20 -04:00
drm drm: Kill user_modes list and the associated ioctls 2013-04-30 10:03:07 +10:00
linux net_sched: restore "linklayer atm" handling 2013-09-14 06:54:55 -07:00
mtd
rdma IB/uverbs: Implement memory windows support in uverbs 2013-02-21 11:59:09 -08:00
scsi FCoE Updates for 3.9 2013-03-01 09:10:08 +00:00
sound ALSA: add DSD formats 2013-04-18 10:02:33 +02:00
video
xen
Kbuild