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path: root/net/ipv4/tcp_cong.c
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2012-08-02tcp: Apply device TSO segment limit earlierBen Hutchings
Cache the device gso_max_segs in sock::sk_gso_max_segs and use it to limit the size of TSO skbs. This avoids the need to fall back to software GSO for local TCP senders. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20tcp: fix ABC in tcp_slow_start()Eric Dumazet
When/if sysctl_tcp_abc > 1, we expect to increase cwnd by 2 if the received ACK acknowledges more than 2*MSS bytes, in tcp_slow_start() Problem is this RFC 3465 statement is not correctly coded, as the while () loop increases snd_cwnd one by one. Add a new variable to avoid this off-by one error. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Nandita Dukkipati <nanditad@google.com> Cc: John Heffner <johnwheffner@gmail.com> Cc: Stephen Hemminger <shemminger@vyatta.com> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-17tcp: bool conversionsEric Dumazet
bool conversions where possible. __inline__ -> inline space cleanups Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-12net: ipv4: Standardize prefixes for message loggingJoe Perches
Add #define pr_fmt(fmt) as appropriate. Add "IPv4: ", "TCP: ", and "IPsec: " to appropriate files. Standardize on "UDPLite: " for appropriate uses. Some prefixes were previously "UDPLITE: " and "UDP-Lite: ". Add KBUILD_MODNAME ": " to icmp and gre. Remove embedded prefixes as appropriate. Add missing "\n" to pr_info in gre.c. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-11net: Convert printks to pr_<level>Joe Perches
Use a more current kernel messaging style. Convert a printk block to print_hex_dump. Coalesce formats, align arguments. Use %s, __func__ instead of embedding function names. Some messages that were prefixed with <foo>_close are now prefixed with <foo>_fini. Some ah4 and esp messages are now not prefixed with "ip ". The intent of this patch is to later add something like #define pr_fmt(fmt) "IPv4: " fmt. to standardize the output messages. Text size is trivially reduced. (x86-32 allyesconfig) $ size net/ipv4/built-in.o* text data bss dec hex filename 887888 31558 249696 1169142 11d6f6 net/ipv4/built-in.o.new 887934 31558 249800 1169292 11d78c net/ipv4/built-in.o.old Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-29tcp: do not scale TSO segment size with reordering degreeNeal Cardwell
Since 2005 (c1b4a7e69576d65efc31a8cea0714173c2841244) tcp_tso_should_defer has been using tcp_max_burst() as a target limit for deciding how large to make outgoing TSO packets when not using sysctl_tcp_tso_win_divisor. But since 2008 (dd9e0dda66ba38a2ddd1405ac279894260dc5c36) tcp_max_burst() returns the reordering degree. We should not have tcp_tso_should_defer attempt to build larger segments just because there is more reordering. This commit splits the notion of deferral size used in TSO from the notion of burst size used in cwnd moderation, and returns the TSO deferral limit to its original value. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-27net/ipv4: Eliminate kstrdup memory leakJulia Lawall
The string clone is only used as a temporary copy of the argument val within the while loop, and so it should be freed before leaving the function. The call to strsep, however, modifies clone, so a pointer to the front of the string is kept in saved_clone, to make it possible to free it. The sematic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @r exists@ local idexpression x; expression E; identifier l; statement S; @@ *x= \(kasprintf\|kstrdup\)(...); ... if (x == NULL) S ... when != kfree(x) when != E = x if (...) { <... when != kfree(x) * goto l; ...> * return ...; } // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2009-08-14Networking: use CAP_NET_ADMIN when deciding to call request_moduleEric Paris
The networking code checks CAP_SYS_MODULE before using request_module() to try to load a kernel module. While this seems reasonable it's actually weakening system security since we have to allow CAP_SYS_MODULE for things like /sbin/ip and bluetoothd which need to be able to trigger module loads. CAP_SYS_MODULE actually grants those binaries the ability to directly load any code into the kernel. We should instead be protecting modprobe and the modules on disk, rather than granting random programs the ability to load code directly into the kernel. Instead we are going to gate those networking checks on CAP_NET_ADMIN which still limits them to root but which does not grant those processes the ability to load arbitrary code into the kernel. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Paul Moore <paul.moore@hp.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: James Morris <jmorris@namei.org>
2009-03-02tcp: add helper for AI algorithmIlpo Järvinen
It seems that implementation in yeah was inconsistent to what other did as it would increase cwnd one ack earlier than the others do. Size benefits: bictcp_cong_avoid | -36 tcp_cong_avoid_ai | +52 bictcp_cong_avoid | -34 tcp_scalable_cong_avoid | -36 tcp_veno_cong_avoid | -12 tcp_yeah_cong_avoid | -38 = -104 bytes total Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-16net: Remove CONFIG_KMOD from net/ (towards removing CONFIG_KMOD entirely)Johannes Berg
Some code here depends on CONFIG_KMOD to not try to load protocol modules or similar, replace by CONFIG_MODULES where more than just request_module depends on CONFIG_KMOD and and also use try_then_request_module in ebtables. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-29tcp: Limit cwnd growth when deferring for GSOJohn Heffner
This fixes inappropriately large cwnd growth on sender-limited flows when GSO is enabled, limiting cwnd growth to 64k. Signed-off-by: John Heffner <johnwheffner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-29tcp: Allow send-limited cwnd to grow up to max_burst when gso disabledJohn Heffner
This changes the logic in tcp_is_cwnd_limited() so that cwnd may grow up to tcp_max_burst() even when sk_can_gso() is false, or when sysctl_tcp_tso_win_divisor != 0. Signed-off-by: John Heffner <johnwheffner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Uninline tcp_is_cwnd_limitedIlpo Järvinen
net/ipv4/tcp_cong.c: tcp_reno_cong_avoid | -65 1 function changed, 65 bytes removed, diff: -65 net/ipv4/arp.c: arp_ignore | -5 1 function changed, 5 bytes removed, diff: -5 net/ipv4/tcp_bic.c: bictcp_cong_avoid | -57 1 function changed, 57 bytes removed, diff: -57 net/ipv4/tcp_cubic.c: bictcp_cong_avoid | -61 1 function changed, 61 bytes removed, diff: -61 net/ipv4/tcp_highspeed.c: hstcp_cong_avoid | -63 1 function changed, 63 bytes removed, diff: -63 net/ipv4/tcp_hybla.c: hybla_cong_avoid | -85 1 function changed, 85 bytes removed, diff: -85 net/ipv4/tcp_htcp.c: htcp_cong_avoid | -57 1 function changed, 57 bytes removed, diff: -57 net/ipv4/tcp_veno.c: tcp_veno_cong_avoid | -52 1 function changed, 52 bytes removed, diff: -52 net/ipv4/tcp_scalable.c: tcp_scalable_cong_avoid | -61 1 function changed, 61 bytes removed, diff: -61 net/ipv4/tcp_yeah.c: tcp_yeah_cong_avoid | -75 1 function changed, 75 bytes removed, diff: -75 net/ipv4/tcp_illinois.c: tcp_illinois_cong_avoid | -54 1 function changed, 54 bytes removed, diff: -54 net/dccp/ccids/ccid3.c: ccid3_update_send_interval | -7 ccid3_hc_tx_packet_recv | +7 2 functions changed, 7 bytes added, 7 bytes removed, diff: +0 net/ipv4/tcp_cong.c: tcp_is_cwnd_limited | +88 1 function changed, 88 bytes added, diff: +88 built-in.o: 14 functions changed, 95 bytes added, 642 bytes removed, diff: -547 ...Again some gcc artifacts visible as well. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Cong.ctrl modules: remove unused good_ack from cong_avoidIlpo Järvinen
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-18[TCP]: remove unused argument to cong_avoid opStephen Hemminger
None of the existing TCP congestion controls use the rtt value pased in the ca_ops->cong_avoid interface. Which is lucky because seq_rtt could have been -1 when handling a duplicate ack. Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-17[TCP] slow start: Make comments and code logic clearer.Stephen Hemminger
Add more comments to describe our version of tcp_slow_start(). Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[TCP]: Congestion control API update.Stephen Hemminger
Do some simple changes to make congestion control API faster/cleaner. * use ktime_t rather than timeval * merge rtt sampling into existing ack callback this means one indirect call versus two per ack. * use flags bits to store options/settings Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[TCP]: Add RFC3742 Limited Slow-Start, controlled by variable ↵John Heffner
sysctl_tcp_max_ssthresh. Signed-off-by: John Heffner <jheffner@psc.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-23[TCP]: Congestion control initialization.Stephen Hemminger
Change to defer congestion control initialization. If setsockopt() was used to change TCP_CONGESTION before connection is established, then protocols that use sequence numbers to keep track of one RTT interval (vegas, illinois, ...) get confused. Change the init hook to be called after handshake. Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-17Various typo fixes.Robert P. J. Day
Correct mis-spellings of "algorithm", "appear", "consistent" and (shame, shame) "kernel". Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2007-02-10[NET] IPV4: Fix whitespace errors.YOSHIFUJI Hideaki
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02[TCP]: Allow autoloading of congestion control via setsockopt.Stephen Hemminger
If user has permision to load modules, then autoload then attempt autoload of TCP congestion module. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02[TCP]: Restrict congestion control choices.Stephen Hemminger
Allow normal users to only choose among a restricted set of congestion control choices. The default is reno and what ever has been configured as default. But the policy can be changed by administrator at any time. For example, to allow any choice: cp /proc/sys/net/ipv4/tcp_available_congestion_control \ /proc/sys/net/ipv4/tcp_allowed_congestion_control Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02[TCP]: Add tcp_available_congestion_control sysctl.Stephen Hemminger
Create /proc/sys/net/ipv4/tcp_available_congestion_control that reflects currently available TCP choices. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-11-01[TCP]: Set default congestion control when no sysctl.Stephen Hemminger
The setting of the default congestion control was buried in the sysctl code so it would not be done properly if SYSCTL was not enabled. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-24[TCP]: default congestion control menuStephen Hemminger
Change how default TCP congestion control is chosen. Don't just use last installed module, instead allow selection during configuration, and make sure and use the default regardless of load order. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-08-29[TCP]: Two RFC3465 Appropriate Byte Count fixes.Daikichi Osuga
1) fix slow start after retransmit timeout 2) fix case of L=2*SMSS acked bytes comparison Signed-off-by: Daikichi Osuga <osugad@s1.nttdocomo.co.jp> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-17[TCP]: Minimum congestion window consolidation.Stephen Hemminger
Many of the TCP congestion methods all just use ssthresh as the minimum congestion window on decrease. Rather than duplicating the code, just have that be the default if that handle in the ops structure is not set. Minor behaviour change to TCP compound. It probably wants to use this (ssthresh) as lower bound, rather than ssthresh/2 because the latter causes undershoot on loss. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-28[TCP]: Fix RFC2465 typo.S P
Signed-off-by: S P <speattle@yahoo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03[TCP]: less inline'sStephen Hemminger
TCP inline usage cleanup: * get rid of inline in several places * replace __inline__ with inline where possible * move functions used in one file out of tcp.h * let compiler decide on used once cases On x86_64: text data bss dec hex filename 3594701 648348 567400 4810449 4966d1 vmlinux.orig 3593133 648580 567400 4809113 496199 vmlinux On sparc64: text data bss dec hex filename 2538278 406152 530392 3474822 350586 vmlinux.ORIG 2536382 406384 530392 3473158 34ff06 vmlinux Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10[TCP]: Appropriate Byte Count supportStephen Hemminger
This is an updated version of the RFC3465 ABC patch originally for Linux 2.6.11-rc4 by Yee-Ting Li. ABC is a way of counting bytes ack'd rather than packets when updating congestion control. The orignal ABC described in the RFC applied to a Reno style algorithm. For advanced congestion control there is little change after leaving slow start. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10[TCP]: add tcp_slow_start helperStephen Hemminger
Move all the code that does linear TCP slowstart to one inline function to ease later patch to add ABC support. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10[TCP]: fix congestion window update when using TSO deferalStephen Hemminger
TCP peformance with TSO over networks with delay is awful. On a 100Mbit link with 150ms delay, we get 4Mbits/sec with TSO and 50Mbits/sec without TSO. The problem is with TSO, we intentionally do not keep the maximum number of packets in flight to fill the window, we hold out to until we can send a MSS chunk. But, we also don't update the congestion window unless we have filled, as per RFC2861. This patch replaces the check for the congestion window being full with something smarter that accounts for TSO. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[ICSK]: Move TCP congestion avoidance members to icskArnaldo Carvalho de Melo
This changeset basically moves tcp_sk()->{ca_ops,ca_state,etc} to inet_csk(), minimal renaming/moving done in this changeset to ease review. Most of it is just changes of struct tcp_sock * to struct sock * parameters. With this we move to a state closer to two interesting goals: 1. Generalisation of net/ipv4/tcp_diag.c, becoming inet_diag.c, being used for any INET transport protocol that has struct inet_hashinfo and are derived from struct inet_connection_sock. Keeps the userspace API, that will just not display DCCP sockets, while newer versions of tools can support DCCP. 2. INET generic transport pluggable Congestion Avoidance infrastructure, using the current TCP CA infrastructure with DCCP. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-23[TCP]: Allow choosing TCP congestion control via sockopt.Stephen Hemminger
Allow using setsockopt to set TCP congestion control to use on a per socket basis. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-23[TCP]: Add pluggable congestion control algorithm infrastructure.Stephen Hemminger
Allow TCP to have multiple pluggable congestion control algorithms. Algorithms are defined by a set of operations and can be built in or modules. The legacy "new RENO" algorithm is used as a starting point and fallback. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>