Commit Graph

2 Commits

Author SHA1 Message Date
Petr Machata
adbe5de966 lib: Move sprint_size() from tc here, add print_size()
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>
2020-12-09 02:30:25 +00:00
Mohit P. Tahiliani
9dced637f8 tc: add support for FQ-PIE packet scheduler
This patch adds support for the FQ-PIE packet Scheduler

Principles:
  - Packets are classified on flows.
  - This is a Stochastic model (as we use a hash, several flows might
                                be hashed to the same slot)
  - Each flow has a PIE 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.
  - Drops during enqueue only.
  - ECN capability is off by default.
  - ECN threshold (if ECN is enabled) is at 10% by default.
  - Uses timestamps to calculate queue delay by default.

Usage:
tc qdisc ... fq_pie [ limit PACKETS ] [ flows NUMBER ]
                    [ target TIME ] [ tupdate TIME ]
                    [ alpha NUMBER ] [ beta NUMBER ]
                    [ quantum BYTES ] [ memory_limit BYTES ]
                    [ ecn_prob PERCENTAGE ] [ [no]ecn ]
                    [ [no]bytemode ] [ [no_]dq_rate_estimator ]

defaults:
  limit: 10240 packets, flows: 1024
  target: 15 ms, tupdate: 15 ms (in jiffies)
  alpha: 1/8, beta : 5/4
  quantum: device MTU, memory_limit: 32 Mb
  ecnprob: 10%, ecn: off
  bytemode: off, dq_rate_estimator: off

Signed-off-by: Mohit P. Tahiliani <tahiliani@nitk.edu.in>
Signed-off-by: Sachin D. Patil <sdp.sachin@gmail.com>
Signed-off-by: V. Saicharan <vsaicharan1998@gmail.com>
Signed-off-by: Mohit Bhasi <mohitbhasi1998@gmail.com>
Signed-off-by: Leslie Monis <lesliemonis@gmail.com>
Signed-off-by: Gautam Ramakrishnan <gautamramk@gmail.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
2020-02-04 03:24:39 -08:00