The functions print_rate() and sprint_rate() are useful for formatting
rate-like values. The DCB tool would find these useful in the maxrate
subtool. However, the current interface to these functions uses a global
variable use_iec as a flag indicating whether 1024- or 1000-based powers
should be used when formatting the rate value. For general use, a global
variable is not a great way of passing arguments to a function. Besides, it
is unlike most other printing functions in that it deals in buffers and
ignores JSON.
Therefore make the interface to print_rate() explicit by converting use_iec
to an ordinary parameter. Since the interface changes anyway, convert it to
follow the pattern of other json_print functions (except for the
now-explicit use_iec parameter). Move to json_print.c.
Add a wrapper to tc, so that all the call sites do not need to repeat the
use_iec global variable argument, and convert all call sites.
In q_cake.c, the conversion is not straightforward due to usage of a macro
that is shared across numerous data types. Simply hand-roll the
corresponding code, which seems better than making an extra helper for one
call site.
Drop sprint_rate() now that everybody just uses print_rate().
Signed-off-by: Petr Machata <me@pmachata.org>
Signed-off-by: David Ahern <dsahern@gmail.com>
As the man page for tc netem states:
To use the Bernoulli model, the only needed parameter is p while the
others will be set to the default values r=1-p, 1-h=1 and 1-k=0.
However r parameter is erroneusly set to 1, and not to 1-p.
Fix this using the same approach of the 4-state loss model.
Fixes: 3c7950af59 ("netem: add support for 4 state and GE loss model")
Signed-off-by: Andrea Claudi <aclaudi@redhat.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Add JSON output support to q_netem.
The normal output is untouched.
In JSON output always use seconds as the base of time units,
and non-percentage numbers (0.01 instead of 1%). Try to always
report the fields, even if they are zero.
All this should make the output more machine-friendly.
v2: less macroes
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Every tool in the iproute2 package have one or more function to show
an help message to the user. Some of these functions print the help
line by line with a series of printf call, e.g. ip/xfrm_state.c does
60 fprintf calls.
If we group all the calls to a single one and just concatenate strings,
we save a lot of libc calls and thus object size. The size difference
of the compiled binaries calculated with bloat-o-meter is:
ip/ip:
add/remove: 0/0 grow/shrink: 5/15 up/down: 103/-4796 (-4693)
Total: Before=672591, After=667898, chg -0.70%
ip/rtmon:
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-54 (-54)
Total: Before=48879, After=48825, chg -0.11%
tc/tc:
add/remove: 0/2 grow/shrink: 31/10 up/down: 882/-6133 (-5251)
Total: Before=351912, After=346661, chg -1.49%
bridge/bridge:
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-459 (-459)
Total: Before=70502, After=70043, chg -0.65%
misc/lnstat:
add/remove: 0/1 grow/shrink: 1/0 up/down: 48/-486 (-438)
Total: Before=9960, After=9522, chg -4.40%
tipc/tipc:
add/remove: 0/0 grow/shrink: 1/1 up/down: 18/-62 (-44)
Total: Before=79182, After=79138, chg -0.06%
While at it, indent some strings which were starting at column 0,
and use tabs where possible, to have a consistent style across helps.
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Extend slotting with support for non-uniform distributions. This is
similar to netem's non-uniform distribution delay feature.
Syntax:
slot distribution DISTRIBUTION DELAY JITTER [packets MAX_PACKETS] \
[bytes MAX_BYTES]
The syntax and use of the distribution table is the same as in the
non-uniform distribution delay feature. A file DISTRIBUTION must be
present in TC_LIB_DIR (e.g. /usr/lib/tc) containing numbers scaled by
NETEM_DIST_SCALE. A random value x is selected from the table and it
takes DELAY + ( x * JITTER ) as delay. Correlation between values is not
supported.
Examples:
Normal distribution delay with mean = 800us and stdev = 100us.
> tc qdisc add dev eth0 root netem slot distribution normal \
800us 100us
Optionally set the max slot size in bytes and/or packets.
> tc qdisc add dev eth0 root netem slot distribution normal \
800us 100us bytes 64k packets 42
Signed-off-by: Yousuk Seung <ysseung@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Dave Taht <dave.taht@gmail.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Slotting is a crude approximation of the behaviors of shared media such
as cable, wifi, and LTE, which gather up a bunch of packets within a
varying delay window and deliver them, relative to that, nearly all at
once.
It works within the existing loss, duplication, jitter and delay
parameters of netem. Some amount of inherent latency must be specified,
regardless.
The new "slot" parameter specifies a minimum and maximum delay between
transmission attempts.
The "bytes" and "packets" parameters can be used to limit the amount of
information transferred per slot.
Examples of use:
tc qdisc add dev eth0 root netem delay 200us \
slot 800us 10ms bytes 64k packets 42
A more correct example, using stacked netem instances and a packet limit
to emulate a tail drop wifi queue with slots and variable packet
delivery, with a 200Mbit isochronous underlying rate, and 20ms path
delay:
tc qdisc add dev eth0 root handle 1: netem delay 20ms rate 200mbit \
limit 10000
tc qdisc add dev eth0 parent 1:1 handle 10:1 netem delay 200us \
slot 800us 10ms bytes 64k packets 42 limit 512
Signed-off-by: Yousuk Seung <ysseung@google.com>
Signed-off-by: Dave Taht <dave.taht@gmail.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Here we are partially reverting commit c14f9d92ee
"treewide: Use addattr_nest()/addattr_nest_end() to handle nested
attributes" .
As discussed in [1], changing from the 'manually' coded version that
used addattr_l() to addattr_nest_compat() wasn't functionally
equivalent, because now the messages have extra fields appended to it.
This introduced a regression since the implementation of parse_attr()
from both mqprio and netem can't handle this new message format.
Without this fix, mqprio returns an error. netem won't return an error
but its internal configuration ends up wrong.
As an example, this can be reproduced by the following commands when
this patch is not applied:
1) mqprio
$ tc qdisc replace dev enp3s0 parent root handle 100 mqprio \
num_tc 3 map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 \
queues 1@0 1@1 2@2 hw 0
RTNETLINK answers: Numerical result out of range
2) netem
$ tc qdisc add dev enp3s0 root netem rate 5kbit 20 100 5 \
distribution normal latency 1 1
$ tc -s qdisc
(...)
qdisc netem 8001: dev enp3s0 root refcnt 9 limit 1000 delay 0us 0us
Sent 402 bytes 1 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
(...)
With this patch applied, the tc -s qdisc command above for netem instead
reads:
(...)
qdisc netem 8002: dev enp3s0 root refcnt 9 limit 1000 delay 0us 0us \
rate 5Kbit packetoverhead 20 cellsize 100 celloverhead 5
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
(...)
[1] https://patchwork.ozlabs.org/patch/867860/#1893405
Fixes: c14f9d92ee ("treewide: Use addattr_nest()/addattr_nest_end() to handle nested attributes")
Reported-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
We have helper routines to support nested attribute addition into
netlink buffer: use them instead of open coding.
Use addattr_nest_compat()/addattr_nest_compat_end() where appropriate.
Signed-off-by: Serhey Popovych <serhe.popovych@gmail.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
This patch adapts the tc command line interface to allow bandwidth limits
to be specified as a percentage of the interface's capacity.
Adding this functionality requires passing the specified device string to
each class/qdisc which changes the prototype for a couple of functions: the
.parse_qopt and .parse_copt interfaces. The device string is a required
parameter for tc-qdisc and tc-class, and when not specified, the kernel
returns ENODEV. In this patch, if the user tries to specify a bandwidth
percentage without naming the device, we return an error from userspace.
Signed-off-by: Nishanth Devarajan<ndev2021@gmail.com>
Assuming 'opt' might be NULL, move the call to RTA_PAYLOAD to after the
check since it dereferences its parameter.
Signed-off-by: Phil Sutter <phil@nwl.cc>
This big patch was compiled by vimgrepping for memset calls and changing
to C99 initializer if applicable. One notable exception is the
initialization of union bpf_attr in tc/tc_bpf.c: changing it would break
for older gcc versions (at least <=3.4.6).
Calls to memset for struct rtattr pointer fields for parse_rtattr*()
were just dropped since they are not needed.
The changes here allowed the compiler to discover some unused variables,
so get rid of them, too.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
First, the default value for 1-k is documented as being 0, but is
currently being set to 1. (100%). This causes all packets to be dropped
in the good state if 1-k is not explicitly specified. Fix this by setting
the default to 0.
Second, the 1-h option is parsed correctly, however, the kernel is
expecting "h", not 1-h. Fix this by inverting the "1-h" percentage before
sending to and after receiving from the kernel. This does change the
behavior, but makes it consistent with the netem documentation and the
literature on the Gilbert-Elliot model, which refer to "1-h" and "1-k,"
not "h" or "k" directly.
Last, fix a minor formatting issue for the options reporting.
Signed-off-by: Jay Vosburgh <jay.vosburgh@canonical.com>
The display of the entire netem loss state is shown as if it
were gemodel state, as the loss state information is assigned to the
wrong pointer. Correct this by assigning the loss state to the correct
pointer.
Additionally, attempting to set netem loss state will result in
random values in the p14 state probability because the option value
passed to the kernel by tc netem is not parsed or initialized. Fix this
by supplying a default value of 0 for p14 and parsing the p14 value if
one is supplied.
Signed-off-by: Jay Vosburgh <jay.vosburgh@canonical.com>
netem support 64bit rates start from linux-3.13.
Add 64bit rates support in tc tools.
tc qdisc show dev eth0
qdisc netem 1: dev eth4 root refcnt 2 limit 1000 rate 35Gbit
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Acked-by: Eric Dumazet <edumazet@google.com>
This patch provides support for marking packets with ECN instead of
dropping them with netem. This makes it possible to make use of the
netem ECN marking feature that was added recently to the kernel.
Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com>
(Resending patch since it looks like my earlier mail did not make it to
netdev).
netem reordering requires that the delay parameter be given. Currently, if no
delay is given, tc prints the error message but still installs the qdisc. Fix
this by printing the usage and failing cleanly.
Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com>
This patch add rate shaping as well as cell support. The link-rate can be
specified via rate options. Three optional arguments control the cell
knobs: packet-overhead, cell-size, cell-overhead. To ratelimit eth0 root
queue to 5kbit/s, with a 20 byte packet overhead, 100 byte cell size and
a 5 byte per cell overhead:
tc qdisc add dev eth0 root netem rate 5kbit 20 100 5
Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
get_distribution() returns an int.
cppcheck reported:
[tc/q_netem.c:243]: (style) Checking if unsigned variable 'dist_size' is less than zero.
The mismatch actually rendered the error checking
after get_distribution() ineffective.
Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
[IPROUTE]: Add sprint_ticks() function and use in CBQ
Add helper function to print ticks to avoid assumptions about clock
resolution in CBQ.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
[IPROUTE]: Replace "usec" by "time" in function names
Rename functions containing "usec" since they don't necessarily return
usec units anymore.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
When using tc to change netem attributes, only those values
on the command line should be passed down, others should
remain unchanged.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
