Netem works better if there if packets are just queued in the inner discipline
rather than having a separate delayed queue. Change to use the dequeue/requeue
to peek like TBF does.
By doing this potential qlen problems with the old method are avoided. The problems
happened when the netem_run that moved packets from the inner discipline to the nested
discipline failed (because inner queue was full). This happened in dequeue, so the
effective qlen of the netem would be decreased (because of the drop), but there was
no way to keep the outer qdisc (caller of netem dequeue) in sync.
The problem window is still there since this patch doesn't address the issue of
requeue failing in netem_dequeue, but that shouldn't happen since the sequence dequeue/requeue
should always work. Long term correct fix is to implement qdisc->peek in all the qdisc's
to allow for this (needed by several other qdisc's as well).
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Handle duplication of packets in netem by re-inserting at top of qdisc tree.
This avoid problems with qlen accounting with nested qdisc. This recursion
requires no additional locking but will potentially increase stack depth.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Long standing bug.
Policy to repeat an action never worked.
Signed-off-by: J Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix qlen underrun when doing duplication with netem. If netem is used
as leaf discipline, then the parent needs to be tweaked when packets
are duplicated.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Netem currently dumps packets into the queue when timer expires. This
patch makes work by self-clocking (more like TBF). It fixes a bug
when 0 delay is requested (only doing loss or duplication).
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Due to bugs in netem (fixed by later patches), it is possible to get qdisc
qlen to go negative. If this happens the CPU ends up spinning forever
in qdisc_run(). So add a BUG_ON() to trap it.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some network drivers call netif_stop_queue() when detecting loss of
carrier. This leads to packets being queued up at the qdisc level for
an unbound period of time. In order to prevent this effect, the core
networking stack will now cease to queue packets for any device, that
is operationally down (i.e. the queue is flushed and disabled).
Signed-off-by: Tommy S. Christensen <tommy.christensen@tpack.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
htb_enqueue(): Free skb and return NET_XMIT_DROP if a packet is
destined for the direct_queue but the direct_queue is full. (Before
this: erroneously returned NET_XMIT_SUCCESS even though the packet was
not enqueued)
Signed-off-by: Asim Shankar <asimshankar@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a trivial fix for a typo on Kconfig, where the Generic Random Early
Detection algorithm is abbreviated as RED instead of GRED.
Signed-off-by: Lucas Correia Villa Real <lucasvr@gobolinux.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Calculate hashtable size to fit into a page instead of a hardcoded
256 buckets hash table. Results in a 1024 buckets hashtable on
most systems.
Replace old naive extract-8-lsb-bits algorithm with a better
algorithm xor'ing 3 or 4 bit fields at the size of the hashtable
array index in order to improve distribution if the majority of
the lower bits are unused while keeping zero collision behaviour
for the most common use case.
Thanks to Wang Jian <lark@linux.net.cn> for bringing this issue
to attention and to Eran Mann <emann@mrv.com> for the initial
idea for this new algorithm.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
And provide an example simply action in order to
demonstrate usage.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Stephen Hemminger