diff options
author | Gerrit Renker <gerrit@erg.abdn.ac.uk> | 2009-01-05 00:42:53 -0500 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2009-01-05 00:42:53 -0500 |
commit | ddebc973c56b51b4e5d84d606f0430d81b895d67 (patch) | |
tree | cebe0e4461346072b2063132fc1d9cf8c3e148f1 /net/dccp/ccids | |
parent | 6ea2fde13abd3444008ab5e9585f9ed249e6047e (diff) |
dccp: Lockless integration of CCID congestion-control plugins
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 <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dccp/ccids')
-rw-r--r-- | net/dccp/ccids/Kconfig | 70 | ||||
-rw-r--r-- | net/dccp/ccids/Makefile | 8 | ||||
-rw-r--r-- | net/dccp/ccids/ccid2.c | 22 | ||||
-rw-r--r-- | net/dccp/ccids/ccid3.c | 23 |
4 files changed, 25 insertions, 98 deletions
diff --git a/net/dccp/ccids/Kconfig b/net/dccp/ccids/Kconfig index 12275943eab8..b30f049cf1d3 100644 --- a/net/dccp/ccids/Kconfig +++ b/net/dccp/ccids/Kconfig | |||
@@ -1,80 +1,52 @@ | |||
1 | menu "DCCP CCIDs Configuration (EXPERIMENTAL)" | 1 | menu "DCCP CCIDs Configuration (EXPERIMENTAL)" |
2 | depends on EXPERIMENTAL | 2 | depends on EXPERIMENTAL |
3 | 3 | ||
4 | config IP_DCCP_CCID2 | ||
5 | tristate "CCID2 (TCP-Like) (EXPERIMENTAL)" | ||
6 | def_tristate IP_DCCP | ||
7 | select IP_DCCP_ACKVEC | ||
8 | ---help--- | ||
9 | CCID 2, TCP-like Congestion Control, denotes Additive Increase, | ||
10 | Multiplicative Decrease (AIMD) congestion control with behavior | ||
11 | modelled directly on TCP, including congestion window, slow start, | ||
12 | timeouts, and so forth [RFC 2581]. CCID 2 achieves maximum | ||
13 | bandwidth over the long term, consistent with the use of end-to-end | ||
14 | congestion control, but halves its congestion window in response to | ||
15 | each congestion event. This leads to the abrupt rate changes | ||
16 | typical of TCP. Applications should use CCID 2 if they prefer | ||
17 | maximum bandwidth utilization to steadiness of rate. This is often | ||
18 | the case for applications that are not playing their data directly | ||
19 | to the user. For example, a hypothetical application that | ||
20 | transferred files over DCCP, using application-level retransmissions | ||
21 | for lost packets, would prefer CCID 2 to CCID 3. On-line games may | ||
22 | also prefer CCID 2. See RFC 4341 for further details. | ||
23 | |||
24 | CCID2 is the default CCID used by DCCP. | ||
25 | |||
26 | config IP_DCCP_CCID2_DEBUG | 4 | config IP_DCCP_CCID2_DEBUG |
27 | bool "CCID2 debugging messages" | 5 | bool "CCID-2 debugging messages" |
28 | depends on IP_DCCP_CCID2 | 6 | ---help--- |
29 | ---help--- | 7 | Enable CCID-2 specific debugging messages. |
30 | Enable CCID2-specific debugging messages. | ||
31 | 8 | ||
32 | When compiling CCID2 as a module, this debugging output can | 9 | The debugging output can additionally be toggled by setting the |
33 | additionally be toggled by setting the ccid2_debug module | 10 | ccid2_debug parameter to 0 or 1. |
34 | parameter to 0 or 1. | ||
35 | 11 | ||
36 | If in doubt, say N. | 12 | If in doubt, say N. |
37 | 13 | ||
38 | config IP_DCCP_CCID3 | 14 | config IP_DCCP_CCID3 |
39 | tristate "CCID3 (TCP-Friendly) (EXPERIMENTAL)" | 15 | bool "CCID-3 (TCP-Friendly) (EXPERIMENTAL)" |
40 | def_tristate IP_DCCP | 16 | def_bool y if (IP_DCCP = y || IP_DCCP = m) |
41 | select IP_DCCP_TFRC_LIB | 17 | select IP_DCCP_TFRC_LIB |
42 | ---help--- | 18 | ---help--- |
43 | CCID 3 denotes TCP-Friendly Rate Control (TFRC), an equation-based | 19 | CCID-3 denotes TCP-Friendly Rate Control (TFRC), an equation-based |
44 | rate-controlled congestion control mechanism. TFRC is designed to | 20 | rate-controlled congestion control mechanism. TFRC is designed to |
45 | be reasonably fair when competing for bandwidth with TCP-like flows, | 21 | be reasonably fair when competing for bandwidth with TCP-like flows, |
46 | where a flow is "reasonably fair" if its sending rate is generally | 22 | where a flow is "reasonably fair" if its sending rate is generally |
47 | within a factor of two of the sending rate of a TCP flow under the | 23 | within a factor of two of the sending rate of a TCP flow under the |
48 | same conditions. However, TFRC has a much lower variation of | 24 | same conditions. However, TFRC has a much lower variation of |
49 | throughput over time compared with TCP, which makes CCID 3 more | 25 | throughput over time compared with TCP, which makes CCID-3 more |
50 | suitable than CCID 2 for applications such streaming media where a | 26 | suitable than CCID-2 for applications such streaming media where a |
51 | relatively smooth sending rate is of importance. | 27 | relatively smooth sending rate is of importance. |
52 | 28 | ||
53 | CCID 3 is further described in RFC 4342, | 29 | CCID-3 is further described in RFC 4342, |
54 | http://www.ietf.org/rfc/rfc4342.txt | 30 | http://www.ietf.org/rfc/rfc4342.txt |
55 | 31 | ||
56 | The TFRC congestion control algorithms were initially described in | 32 | The TFRC congestion control algorithms were initially described in |
57 | RFC 3448. | 33 | RFC 5448. |
58 | 34 | ||
59 | This text was extracted from RFC 4340 (sec. 10.2), | 35 | This text was extracted from RFC 4340 (sec. 10.2), |
60 | http://www.ietf.org/rfc/rfc4340.txt | 36 | http://www.ietf.org/rfc/rfc4340.txt |
61 | |||
62 | To compile this CCID as a module, choose M here: the module will be | ||
63 | called dccp_ccid3. | ||
64 | 37 | ||
65 | If in doubt, say M. | 38 | If in doubt, say N. |
66 | 39 | ||
67 | config IP_DCCP_CCID3_DEBUG | 40 | config IP_DCCP_CCID3_DEBUG |
68 | bool "CCID3 debugging messages" | 41 | bool "CCID-3 debugging messages" |
69 | depends on IP_DCCP_CCID3 | 42 | depends on IP_DCCP_CCID3 |
70 | ---help--- | 43 | ---help--- |
71 | Enable CCID3-specific debugging messages. | 44 | Enable CCID-3 specific debugging messages. |
72 | 45 | ||
73 | When compiling CCID3 as a module, this debugging output can | 46 | The debugging output can additionally be toggled by setting the |
74 | additionally be toggled by setting the ccid3_debug module | 47 | ccid3_debug parameter to 0 or 1. |
75 | parameter to 0 or 1. | ||
76 | 48 | ||
77 | If in doubt, say N. | 49 | If in doubt, say N. |
78 | 50 | ||
79 | config IP_DCCP_CCID3_RTO | 51 | config IP_DCCP_CCID3_RTO |
80 | int "Use higher bound for nofeedback timer" | 52 | int "Use higher bound for nofeedback timer" |
diff --git a/net/dccp/ccids/Makefile b/net/dccp/ccids/Makefile index 438f20bccff7..cdaefffbb777 100644 --- a/net/dccp/ccids/Makefile +++ b/net/dccp/ccids/Makefile | |||
@@ -1,9 +1 @@ | |||
1 | obj-$(CONFIG_IP_DCCP_CCID3) += dccp_ccid3.o | ||
2 | |||
3 | dccp_ccid3-y := ccid3.o | ||
4 | |||
5 | obj-$(CONFIG_IP_DCCP_CCID2) += dccp_ccid2.o | ||
6 | |||
7 | dccp_ccid2-y := ccid2.o | ||
8 | |||
9 | obj-y += lib/ | obj-y += lib/ | |
diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c index c9ea19a4d85e..d235294ace23 100644 --- a/net/dccp/ccids/ccid2.c +++ b/net/dccp/ccids/ccid2.c | |||
@@ -768,10 +768,9 @@ static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) | |||
768 | } | 768 | } |
769 | } | 769 | } |
770 | 770 | ||
771 | static struct ccid_operations ccid2 = { | 771 | struct ccid_operations ccid2_ops = { |
772 | .ccid_id = DCCPC_CCID2, | 772 | .ccid_id = DCCPC_CCID2, |
773 | .ccid_name = "TCP-like", | 773 | .ccid_name = "TCP-like", |
774 | .ccid_owner = THIS_MODULE, | ||
775 | .ccid_hc_tx_obj_size = sizeof(struct ccid2_hc_tx_sock), | 774 | .ccid_hc_tx_obj_size = sizeof(struct ccid2_hc_tx_sock), |
776 | .ccid_hc_tx_init = ccid2_hc_tx_init, | 775 | .ccid_hc_tx_init = ccid2_hc_tx_init, |
777 | .ccid_hc_tx_exit = ccid2_hc_tx_exit, | 776 | .ccid_hc_tx_exit = ccid2_hc_tx_exit, |
@@ -784,22 +783,5 @@ static struct ccid_operations ccid2 = { | |||
784 | 783 | ||
785 | #ifdef CONFIG_IP_DCCP_CCID2_DEBUG | 784 | #ifdef CONFIG_IP_DCCP_CCID2_DEBUG |
786 | module_param(ccid2_debug, bool, 0644); | 785 | module_param(ccid2_debug, bool, 0644); |
787 | MODULE_PARM_DESC(ccid2_debug, "Enable debug messages"); | 786 | MODULE_PARM_DESC(ccid2_debug, "Enable CCID-2 debug messages"); |
788 | #endif | 787 | #endif |
789 | |||
790 | static __init int ccid2_module_init(void) | ||
791 | { | ||
792 | return ccid_register(&ccid2); | ||
793 | } | ||
794 | module_init(ccid2_module_init); | ||
795 | |||
796 | static __exit void ccid2_module_exit(void) | ||
797 | { | ||
798 | ccid_unregister(&ccid2); | ||
799 | } | ||
800 | module_exit(ccid2_module_exit); | ||
801 | |||
802 | MODULE_AUTHOR("Andrea Bittau <a.bittau@cs.ucl.ac.uk>"); | ||
803 | MODULE_DESCRIPTION("DCCP TCP-Like (CCID2) CCID"); | ||
804 | MODULE_LICENSE("GPL"); | ||
805 | MODULE_ALIAS("net-dccp-ccid-2"); | ||
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index 3b8bd7ca6761..a27b7f4c19c5 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c | |||
@@ -940,10 +940,9 @@ static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len, | |||
940 | return 0; | 940 | return 0; |
941 | } | 941 | } |
942 | 942 | ||
943 | static struct ccid_operations ccid3 = { | 943 | struct ccid_operations ccid3_ops = { |
944 | .ccid_id = DCCPC_CCID3, | 944 | .ccid_id = DCCPC_CCID3, |
945 | .ccid_name = "TCP-Friendly Rate Control", | 945 | .ccid_name = "TCP-Friendly Rate Control", |
946 | .ccid_owner = THIS_MODULE, | ||
947 | .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock), | 946 | .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock), |
948 | .ccid_hc_tx_init = ccid3_hc_tx_init, | 947 | .ccid_hc_tx_init = ccid3_hc_tx_init, |
949 | .ccid_hc_tx_exit = ccid3_hc_tx_exit, | 948 | .ccid_hc_tx_exit = ccid3_hc_tx_exit, |
@@ -964,23 +963,5 @@ static struct ccid_operations ccid3 = { | |||
964 | 963 | ||
965 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG | 964 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
966 | module_param(ccid3_debug, bool, 0644); | 965 | module_param(ccid3_debug, bool, 0644); |
967 | MODULE_PARM_DESC(ccid3_debug, "Enable debug messages"); | 966 | MODULE_PARM_DESC(ccid3_debug, "Enable CCID-3 debug messages"); |
968 | #endif | 967 | #endif |
969 | |||
970 | static __init int ccid3_module_init(void) | ||
971 | { | ||
972 | return ccid_register(&ccid3); | ||
973 | } | ||
974 | module_init(ccid3_module_init); | ||
975 | |||
976 | static __exit void ccid3_module_exit(void) | ||
977 | { | ||
978 | ccid_unregister(&ccid3); | ||
979 | } | ||
980 | module_exit(ccid3_module_exit); | ||
981 | |||
982 | MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, " | ||
983 | "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>"); | ||
984 | MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID"); | ||
985 | MODULE_LICENSE("GPL"); | ||
986 | MODULE_ALIAS("net-dccp-ccid-3"); | ||