When displaying sizes of various sorts, tc commonly uses the function
sprint_size() to format the size into a buffer as a human-readable string.
This string is then displayed either using print_string(), or in some code
even fprintf(). As a result, a typical sequence of code when formatting a
size is something like the following:
SPRINT_BUF(b);
print_uint(PRINT_JSON, "foo", NULL, foo);
print_string(PRINT_FP, NULL, "foo %s ", sprint_size(foo, b));
For a concept as broadly useful as size, it would be better to have a
dedicated function in json_print.
To that end, move sprint_size() from tc_util to json_print. Add helpers
print_size() and print_color_size() that wrap arount sprint_size() and
provide the JSON dispatch as appropriate.
Since print_size() should be the preferred interface, convert vast majority
of uses of sprint_size() to print_size(). Two notable exceptions are:
- q_tbf, which does not show the size as such, but uses the string
"$human_readable_size/$cell_size" even in JSON. There is simply no way to
have print_size() emit the same text, because print_size() in JSON mode
should of course just use the raw number, without human-readable frills.
- q_cake, which relies on the existence of sprint_size() in its macro-based
formatting helpers. There might be ways to convert this particular case,
but given q_tbf simply cannot be converted, leave it as is.
Signed-off-by: Petr Machata <me@pmachata.org>
Signed-off-by: David Ahern <dsahern@gmail.com>
Commit 9d18562a2278 ("fq_codel: add batch ability to fq_codel_drop()")
added the new TCA_FQ_CODEL_DROP_BATCH_SIZE parameter, set by default to 64.
Add to tc command the ability to get/set the drop_batch
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
The fq_codel class stat deficit is a signed int. This is a regression
from when JSON output was added.
Fixes: 997f2dc193 ("tc: Add JSON output of fq_codel stats")
Signed-off-by: Benjamin Lee <ben@b1c1l1.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
In oneline mode the line seperator should be \
but several parts of tc aren't doing it right.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
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>
Enable proper JSON output support for fq_codel in `tc -s qdisc` output.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: David Ahern <dsahern@gmail.com>
Add missing documentation of the memory_limit fq_codel parameter and the
ce_threshold codel and fq_codel parameters.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: David Ahern <dsahern@gmail.com>
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>
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>
codel & fq_codel packet schedulers are now able to have a threshold
for CE marking packets, regardless of the drop/nodrop decision taken by
CoDel.
This is particularly useful for dctcp and variants, that do not use
traditional ECN.
Note that fq_codel users would have to specify noecn if ce_threshold is
used, otherwise results would be not very interesting, as ecn is default
on for fq_codel.
$ tc -s qdisc show dev eth1
qdisc codel 8002: root refcnt 45 limit 1000p target 5.0ms ce_threshold
1.0ms interval 100.0ms
Sent 4908469888317 bytes 3351813967 pkt (dropped 0, overlimits 0
requeues 21624365)
rate 37671Mbit 3231836pps backlog 4904740b 250p requeues 21624365
count 0 lastcount 0 ldelay 1.1ms drop_next 0us
maxpacket 68130 ecn_mark 0 drop_overlimit 0 ce_mark 410861803
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fair Queue Codel packet scheduler
Principles :
- Packets are classified (internal classifier or external) on flows.
- This is a Stochastic model (as we use a hash, several flows might
be hashed on same slot)
- Each flow has a CoDel managed queue.
- Flows are linked onto two (Round Robin) lists,
so that new flows have priority on old ones.
- For a given flow, packets are not reordered (CoDel uses a FIFO)
- head drops only.
- ECN capability is on by default.
- Very low memory footprint (64 bytes per flow)
tc qdisc ... fq_codel [ limit PACKETS ] [ flows number ]
[ target TIME ] [ interval TIME ] [ noecn ]
[ quantum BYTES ]
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Dave Taht <dave.taht@bufferbloat.net>
Cc: Kathleen Nichols <nichols@pollere.com>
Cc: Van Jacobson <van@pollere.net>
Cc: Tom Herbert <therbert@google.com>
Cc: Matt Mathis <mattmathis@google.com>
Cc: Nandita Dukkipati <nanditad@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Changli Gao <xiaosuo@gmail.com>
