netem checks PSCHED_TLESS(cb->time_to_send, now) to find out whether it is
allowed to send a packet, which is equivalent to cb->time_to_send < now.
Use !PSCHED_TLESS(now, cb->time_to_send) instead to properly handle
cb->time_to_send == now.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The netem code would call getnstimeofday() and dequeue/requeue after
every packet, even if it was waiting. Avoid this overhead by using
the throttled flag.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In most cases, the next packet will be sent after the
last one. So optimize that case.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The random number generator always generates 32 bit values.
The time values are limited by psched_tdiff_t
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If you setup netem to just delay packets; "tc qdisc ls" will report
the reordering as 100%. Well it's a lie, reorder isn't used unless
gap is set, so just set value to 0 so the output of utility
is correct.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
So that it is also an offset from skb->head, reduces its size from 8 to 4 bytes
on 64bit architectures, allowing us to combine the 4 bytes hole left by the
layer headers conversion, reducing struct sk_buff size to 256 bytes, i.e. 4
64byte cachelines, and since the sk_buff slab cache is SLAB_HWCACHE_ALIGN...
:-)
Many calculations that previously required that skb->{transport,network,
mac}_header be first converted to a pointer now can be done directly, being
meaningful as offsets or pointers.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When peeking at the next packet in a child qdisc by calling dequeue/requeue,
the upper qdisc qlen counter may get out of sync in case the requeue fails.
The qdisc and the child qdisc both have their counter decremented, but since
no packet is given to the upper qdisc it won't decrement its counter itself.
requeue should not fail, so this is mostly for "correctness".
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert the "simple" qdiscs to use qdisc_tree_decrease_qlen() where
necessary:
- all graft operations
- destruction of old child qdiscs in prio, red and tbf change operation
- purging of queue in sfq change operation
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Set parent classids in default qdiscs to allow walking up the tree
from outside the qdiscs. This is needed by the next patch.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
I don't want my code to downgraded to GPLv3 because of
cut-n-pasted the comments. These files which I hold copyright
on were started before it was clear what GPLv3 was going to be.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
The networking emulator can queue SKBs for a very long
time, so if you're using netem on the sender side for
large bandwidth/delay product testing, the SKB socket
send queue sizes become artificially larger.
Correct this by calling skb_orphan() in netem_enqueue().
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace CHECKSUM_HW by CHECKSUM_PARTIAL (for outgoing packets, whose
checksum still needs to be completed) and CHECKSUM_COMPLETE (for
incoming packets, device supplied full checksum).
Patch originally from Herbert Xu, updated by myself for 2.6.18-rc3.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
CONFIG_DEBUG_SLAB found the following bug:
netem_enqueue() in sch_netem.c gets a pointer inside a slab object:
struct netem_skb_cb *cb = (struct netem_skb_cb *)skb->cb;
But then, the slab object may be freed:
skb = skb_unshare(skb, GFP_ATOMIC)
cb is still pointing inside the freed skb, so here is a patch to
initialize cb later, and make it clear that initializing it sooner
is a bad idea.
[From Stephen Hemminger: leave cb unitialized in order to let gcc
complain in case of use before initialization]
Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
The following one line fix is needed to make loss function of
netem work right when doing loss on the local host.
Otherwise, higher layers just recover.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The drop operation is optional and qdiscs must check if childs support it.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Here is a new feature for netem in 2.6.16. It adds the ability to
randomly corrupt packets with netem. A version was done by
Hagen Paul Pfeifer, but I redid it to handle the cases of backwards
compatibility with netlink interface and presence of hardware checksum
offload. It is useful for testing hardware offload in devices.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If two packets were queued to be sent at the same time in the future,
their order would be reversed. This would occur because the queue is
traversed back to front, and a position is found by checking whether
the new packet needs to be sent before the packet being examined. If
the new packet is to be sent at the same time of a previous packet, it
would end up before the old packet in the queue. This patch places
packets in the correct order when they are queued to be sent at a same
time in the future.
Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a version string to help support issues.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Change netem to support packets getting reordered because of variations in
delay. Introduce a special case version of FIFO that queues packets in order
based on the netem delay.
Since netem is classful, those users that don't want jitter based reordering
can just insert a pfifo instead of the default.
This required changes to generic skbuff code to allow finer grain manipulation
of sk_buff_head. Insertion into the middle and reverse walk.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Convert netem to use PSCHED_LESS and warn if requeue fails.
With some of the psched clock sources, the subtraction doesn't
work always work right without wrapping.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Here is a fixed up version of the reorder feature of netem.
It is the same as the earlier patch plus with the bugfix from Julio merged in.
Has expected backwards compatibility behaviour.
Go ahead and merge this one, the TCP strangeness I was seeing was due
to the reordering bug, and previous version of TSO patch.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
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>
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!
