litmus-rt.git/net/dccp/ccids/Kconfig, branch linux-tip

dccp ccid-3: use per-route RTO or TCP RTO as fallback

2010-08-30T20:45:28+00:00

This makes RTAX_RTO_MIN also available to CCID-3, replacing the compile-time
RTO lower bound with a per-route tunable value.

The original Kconfig option solved the problem that a very low RTT (in the
order of HZ) can trigger too frequent and unnecessary reductions of the
sending rate.

This tunable does not affect the initial RTO value of 2 seconds specified in
RFC 5348, section 4.2 and Appendix B. But like the hardcoded Kconfig value,
it allows to adapt to network conditions.

The same effect as the original Kconfig option of 100ms is now achieved by

> ip route replace to unicast 192.168.0.0/24 rto_min 100j dev eth0

(assuming HZ=1000).

Signed-off-by: Gerrit Renker 
Signed-off-by: David S. Miller

net-next-2.6 [PATCH 1/1] dccp: ccids whitespace-cleanup / CodingStyle

2009-09-15T00:02:54+00:00

No code change, cosmetical changes only:

 * whitespace cleanup via scripts/cleanfile,
 * remove self-references to filename at top of files,
 * fix coding style (extraneous brackets),
 * fix documentation style (kernel-doc-nano-HOWTO).

Thanks are due to Ivo Augusto Calado who raised these issues by
submitting good-quality patches.

Signed-off-by: Gerrit Renker 
Signed-off-by: David S. Miller

dccp ccid-3: Fix RFC reference

2009-01-11T08:17:22+00:00

Thanks to Wei and Arnaldo for pointing out the correct
new reference for CCID-3.

Signed-off-by: Gerrit Renker 
Signed-off-by: David S. Miller

dccp: Integrate the TFRC library with DCCP

2009-01-05T05:45:33+00:00

This patch integrates the TFRC library, which is a dependency of CCID-3 (and
CCID-4), with the new use of CCIDs in the DCCP module.		

Signed-off-by: Gerrit Renker 
Signed-off-by: David S. Miller

dccp: Lockless integration of CCID congestion-control plugins

2009-01-05T05:42:53+00:00

Based on Arnaldo's earlier patch, this patch integrates the standardised
CCID congestion control plugins (CCID-2 and CCID-3) of DCCP with dccp.ko:

 * enables a faster connection path by eliminating the need to always go 
   through the CCID registration lock;

 * updates the implementation to use only a single array whose size equals
   the number of configured CCIDs instead of the maximum (256);

 * since the CCIDs are now fixed array elements, synchronization is no
   longer needed, simplifying use and implementation.

CCID-2 is suggested as minimum for a basic DCCP implementation (RFC 4340, 10);
CCID-3 is a standards-track CCID supported by RFC 4342 and RFC 5348.

Signed-off-by: Gerrit Renker 
Signed-off-by: David S. Miller

[TFRC]: Provide central source file and debug facility

2008-01-28T22:56:39+00:00

This patch changes the tfrc_lib module in the following manner:

 (1) a dedicated tfrc source file to call the packet history &
     loss interval init/exit functions.
 (2) a dedicated tfrc_pr_debug macro with toggle switch `tfrc_debug'.

Commiter note: renamed tfrc_module.c to tfrc.c, and made CONFIG_IP_DCCP_CCID3
select IP_DCCP_TFRC_LIB.

Signed-off-by: Gerrit Renker 
Signed-off-by: Ian McDonald 
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

[DCCP]: Remove redundant dependency on IP_DCCP

2008-01-28T22:54:46+00:00

This cleans up the consequences of an earlier patch which
introduced the `if IP_DCCP' clause into net/dccp/Kconfig.

The CCID Kconfig menu is sourced within this clause; as a
consequence, all tests of type `depends on IP_DCCP' are now
redundant.

Signed-off-by: Gerrit Renker 
Signed-off-by: Ian McDonald 
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

[DCCP]: Promote CCID2 as default CCID

2008-01-28T22:54:46+00:00

This patch addresses the following problems:

1. DCCP relies for its proper functioning on having at least one CCID module
enabled (as in TCP plugable congestion control). Currently it is possible to
disable both CCIDs and thus leave the DCCP module in a compiled, but entirely
non-functional state: no sockets can be created when no CCID is available.
Furthermore, the protocol is (again like TCP) not intended to be used without
CCIDs. Last, a non-empty CCID list is needed for doing CCID feature negotiation.

2. Internally the default CCID that is advertised by the Linux host is set to CCID2
(DCCPF_INITIAL_CCID in include/linux/dccp.h). Disabling CCID2 in the Kconfig
menu without changing the defaults leads to a failure `module not found' when
trying to load the dccp module (which internally tries to load the default CCID).

3. The specification (RFC 4340, sec. 10) treats CCID2 somewhat like a
`minimum common denominator'; the specification says that:

* "New connections start with CCID 2 for both endpoints"

* "A DCCP implementation intended for general use, such as an implementation in a
general-purpose operating system kernel, SHOULD implement at least CCID 2.
The intent is to make CCID 2 broadly available for interoperability [...]"

Providing CCID2 as minimum-required CCID (like Reno/Cubic in TCP) thus seems reasonable.

Hence this patch automatically selects CCID2 when DCCP is enabled. Documentation also added.

Discussions with Ian McDonald on this subject are gratefully acknowledged.

Signed-off-by: Gerrit Renker
Signed-off-by: Ian McDonald
Signed-off-by: Arnaldo Carvalho de Melo
Signed-off-by: David S. Miller

[DCCP]: Use higher RTO default for CCID3

2006-12-03T16:50:23+00:00

The TFRC nofeedback timer normally expires after the maximum of 4
RTTs and twice the current send interval (RFC 3448, 4.3). On LANs
with a small RTT this can mean a high processing load and reduced
performance, since then the nofeedback timer is triggered very
frequently.

This patch provides a configuration option to set the bound for the
nofeedback timer, using as default 100 milliseconds.

By setting the configuration option to 0, strict RFC 3448 behaviour
can be enforced for the nofeedback timer.

Signed-off-by: Gerrit Renker 
Signed-off-by: Arnaldo Carvalho de Melo

[DCCP]: Add CCID3 debug support to Kconfig

2006-12-03T05:24:36+00:00

This adds a CCID3 debug option to the configuration menu
which is missing in Kconfig, but already used by the code.

CCID 2 already provides such an entry.

To enable debugging, set CONFIG_IP_DCCP_CCID3_DEBUG=y

NOTE: The use of ccid3_{t,r}x_state_name is safe, since
      now only enum values can appear.

Signed-off-by: Gerrit Renker 
Signed-off-by: Arnaldo Carvalho de Melo