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2006-10-18[TCP]: Bound TSO defer timeJohn Heffner
This patch limits the amount of time you will defer sending a TSO segment to less than two clock ticks, or the time between two acks, whichever is longer. On slow links, deferring causes significant bursts. See attached plots, which show RTT through a 1 Mbps link with a 100 ms RTT and ~100 ms queue for (a) non-TSO, (b) currnet TSO, and (c) patched TSO. This burstiness causes significant jitter, tends to overflow queues early (bad for short queues), and makes delay-based congestion control more difficult. Deferring by a couple clock ticks I believe will have a relatively small impact on performance. Signed-off-by: John Heffner <jheffner@psc.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-10-11[NET]: Use hton{l,s}() for non-initializers.YOSHIFUJI Hideaki
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-28[TCP] net/ipv4/tcp_output.c: trivial annotationsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-22[NET/IPV4/IPV6]: Change some sysctl variables to __read_mostlyBrian Haley
Change net/core, ipv4 and ipv6 sysctl variables to __read_mostly. Couldn't actually measure any performance increase while testing (.3% I consider noise), but seems like the right thing to do. Signed-off-by: Brian Haley <brian.haley@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-22[NET]: Replace CHECKSUM_HW by CHECKSUM_PARTIAL/CHECKSUM_COMPLETEPatrick McHardy
Replace CHECKSUM_HW by CHECKSUM_PARTIAL (for outgoing packets, whose checksum still needs to be completed) and CHECKSUM_COMPLETE (for incoming packets, device supplied full checksum). Patch originally from Herbert Xu, updated by myself for 2.6.18-rc3. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-08-22[TCP]: Limit window scaling if window is clamped.Stephen Hemminger
This small change allows for easy per-route workarounds for broken hosts or middleboxes that are not compliant with TCP standards for window scaling. Rather than having to turn off window scaling globally. This patch allows reducing or disabling window scaling if window clamp is present. Example: Mark Lord reported a problem with 2.6.17 kernel being unable to access http://www.everymac.com # ip route add 216.145.246.23/32 via 10.8.0.1 window 65535 Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-08-07[TCP]: SNMPv2 tcpOutSegs counter errorWei Yongjun
Do not count retransmitted segments. Signed-off-by: Wei Yongjun <yjwei@nanjing-fnst.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-30[NET]: Generalise TSO-specific bits from skb_setup_capsHerbert Xu
This patch generalises the TSO-specific bits from sk_setup_caps by adding the sk_gso_type member to struct sock. This makes sk_setup_caps generic so that it can be used by TCPv6 or UFO. The only catch is that whoever uses this must provide a GSO implementation for their protocol which I think is a fair deal :) For now UFO continues to live without a GSO implementation which is OK since it doesn't use the sock caps field at the moment. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-29[NET]: Add ECN support for TSOMichael Chan
In the current TSO implementation, NETIF_F_TSO and ECN cannot be turned on together in a TCP connection. The problem is that most hardware that supports TSO does not handle CWR correctly if it is set in the TSO packet. Correct handling requires CWR to be set in the first packet only if it is set in the TSO header. This patch adds the ability to turn on NETIF_F_TSO and ECN using GSO if necessary to handle TSO packets with CWR set. Hardware that handles CWR correctly can turn on NETIF_F_TSO_ECN in the dev-> features flag. All TSO packets with CWR set will have the SKB_GSO_TCPV4_ECN set. If the output device does not have the NETIF_F_TSO_ECN feature set, GSO will split the packet up correctly with CWR only set in the first segment. With help from Herbert Xu <herbert@gondor.apana.org.au>. Since ECN can always be enabled with TSO, the SOCK_NO_LARGESEND sock flag is completely removed. Signed-off-by: Michael Chan <mchan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-23[NET]: Merge TSO/UFO fields in sk_buffHerbert Xu
Having separate fields in sk_buff for TSO/UFO (tso_size/ufo_size) is not going to scale if we add any more segmentation methods (e.g., DCCP). So let's merge them. They were used to tell the protocol of a packet. This function has been subsumed by the new gso_type field. This is essentially a set of netdev feature bits (shifted by 16 bits) that are required to process a specific skb. As such it's easy to tell whether a given device can process a GSO skb: you just have to and the gso_type field and the netdev's features field. I've made gso_type a conjunction. The idea is that you have a base type (e.g., SKB_GSO_TCPV4) that can be modified further to support new features. For example, if we add a hardware TSO type that supports ECN, they would declare NETIF_F_TSO | NETIF_F_TSO_ECN. All TSO packets with CWR set would have a gso_type of SKB_GSO_TCPV4 | SKB_GSO_TCPV4_ECN while all other TSO packets would be SKB_GSO_TCPV4. This means that only the CWR packets need to be emulated in software. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17[TCP]: Add tcp_slow_start_after_idle sysctl.David S. Miller
A lot of people have asked for a way to disable tcp_cwnd_restart(), and it seems reasonable to add a sysctl to do that. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-05[TCP]: Avoid skb_pull if possible when trimming headHerbert Xu ~{PmVHI~}
Trimming the head of an skb by calling skb_pull can cause the packet to become unaligned if the length pulled is odd. Since the length is entirely arbitrary for a FIN packet carrying data, this is actually quite common. Unaligned data is not the end of the world, but we should avoid it if it's easily done. In this case it is trivial. Since we're discarding all of the head data it doesn't matter whether we move skb->data forward or back. However, it is still possible to have unaligned skb->data in general. So network drivers should be prepared to handle it instead of crashing. This patch also adds an unlikely marking on len < headlen since partial ACKs on head data are extremely rare in the wild. As the return value of __pskb_trim_head is no longer ever NULL that has been removed. Signed-off-by: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-04-29[TCP]: Fix unlikely usage in tcp_transmit_skb()Hua Zhong
The following unlikely should be replaced by likely because the condition happens every time unless there is a hard error to transmit a packet. Signed-off-by: Hua Zhong <hzhong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-04-19[TCP]: Account skb overhead in tcp_fragmentHerbert Xu
Make sure that we get the full sizeof(struct sk_buff) plus the data size accounted for in skb->truesize. This will create invariants that will allow adding assertion checks on skb->truesize. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-04-18[TCP]: Fix truesize underflowHerbert Xu
There is a problem with the TSO packet trimming code. The cause of this lies in the tcp_fragment() function. When we allocate a fragment for a completely non-linear packet the truesize is calculated for a payload length of zero. This means that truesize could in fact be less than the real payload length. When that happens the TSO packet trimming can cause truesize to become negative. This in turn can cause sk_forward_alloc to be -n * PAGE_SIZE which would trigger the warning. I've copied the code DaveM used in tso_fragment which should work here. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-04-14[IPV4]: Possible cleanups.Adrian Bunk
This patch contains the following possible cleanups: - make the following needlessly global function static: - arp.c: arp_rcv() - remove the following unused EXPORT_SYMBOL's: - devinet.c: devinet_ioctl - fib_frontend.c: ip_rt_ioctl - inet_hashtables.c: inet_bind_bucket_create - inet_hashtables.c: inet_bind_hash - tcp_input.c: sysctl_tcp_abc - tcp_ipv4.c: sysctl_tcp_tw_reuse - tcp_output.c: sysctl_tcp_mtu_probing - tcp_output.c: sysctl_tcp_base_mss Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[TCP]: sysctl to allow TCP window > 32767 sans wscaleRick Jones
Back in the dark ages, we had to be conservative and only allow 15-bit window fields if the window scale option was not negotiated. Some ancient stacks used a signed 16-bit quantity for the window field of the TCP header and would get confused. Those days are long gone, so we can use the full 16-bits by default now. There is a sysctl added so that we can still interact with such old stacks Signed-off-by: Rick Jones <rick.jones2@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[TCP] mtu probing: move tcp-specific data out of inet_connection_sockJohn Heffner
This moves some TCP-specific MTU probing state out of inet_connection_sock back to tcp_sock. Signed-off-by: John Heffner <jheffner@psc.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[TCP]: MTU probingJohn Heffner
Implementation of packetization layer path mtu discovery for TCP, based on the internet-draft currently found at <http://www.ietf.org/internet-drafts/draft-ietf-pmtud-method-05.txt>. Signed-off-by: John Heffner <jheffner@psc.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-11[TCP]: Fix tcp_tso_should_defer() when limit>=65536David S. Miller
That's >= a full sized TSO frame, so we should always return 0 in that case. Based upon a report and initial patch from Lachlan Andrew, final patch suggested by Herbert Xu. 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>
2006-01-03[IP_SOCKGLUE]: Remove most of the tcp specific callsArnaldo Carvalho de Melo
As DCCP needs to be called in the same spots. Now we have a member in inet_sock (is_icsk), set at sock creation time from struct inet_protosw->flags (if INET_PROTOSW_ICSK is set, like for TCP and DCCP) to see if a struct sock instance is a inet_connection_sock for places like the ones in ip_sockglue.c (v4 and v6) where we previously were looking if sk_type was SOCK_STREAM, that is insufficient because we now use the same code for DCCP, that has sk_type SOCK_DCCP. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03[ICSK]: Rename struct tcp_func to struct inet_connection_sock_af_opsArnaldo Carvalho de Melo
And move it to struct inet_connection_sock. DCCP will use it in the upcoming changesets. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-12-06[TCP] Vegas: timestamp before cloneDavid S. Miller
We have to store the congestion control timestamp on the SKB before we clone it, not after. Else we get no timestamping information at all. tcp_transmit_skb() has been reworked so that we can do the timestamp still in one spot, instead of at all the call sites. Problem discovered, and initial fix, from Tom Young <tyo@ee.unimelb.edu.au>. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10[TCP]: speed up SACK processingStephen Hemminger
Use "hints" to speed up the SACK processing. Various forms of this have been used by TCP developers (Web100, STCP, BIC) to avoid the 2x linear search of outstanding segments. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10[TCP]: spelling fixesStephen Hemminger
Minor spelling fixes for TCP code. 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>
2005-10-20[TCP] Allow len == skb->len in tcp_fragmentHerbert Xu
It is legitimate to call tcp_fragment with len == skb->len since that is done for FIN packets and the FIN flag counts as one byte. So we should only check for the len > skb->len case. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-10-13[TCP]: Ratelimit debugging warning.Herbert Xu
Better safe than sorry. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-12[TCP]: Add code to help track down "BUG at net/ipv4/tcp_output.c:438!"Herbert Xu
This is the second report of this bug. Unfortunately the first reporter hasn't been able to reproduce it since to provide more debugging info. So let's apply this patch for 2.6.14 to 1) Make this non-fatal. 2) Provide the info we need to track it down. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-08[PATCH] gfp flags annotations - part 1Al Viro
- added typedef unsigned int __nocast gfp_t; - replaced __nocast uses for gfp flags with gfp_t - it gives exactly the same warnings as far as sparse is concerned, doesn't change generated code (from gcc point of view we replaced unsigned int with typedef) and documents what's going on far better. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-29[TCP]: Revert 6b251858d377196b8cea20e65cae60f584a42735David S. Miller
But retain the comment fix. Alexey Kuznetsov has explained the situation as follows: -------------------- I think the fix is incorrect. Look, the RFC function init_cwnd(mss) is not continuous: f.e. for mss=1095 it needs initial window 1095*4, but for mss=1096 it is 1096*3. We do not know exactly what mss sender used for calculations. If we advertised 1096 (and calculate initial window 3*1096), the sender could limit it to some value < 1096 and then it will need window his_mss*4 > 3*1096 to send initial burst. See? So, the honest function for inital rcv_wnd derived from tcp_init_cwnd() is: init_rcv_wnd(mss)= min { init_cwnd(mss1)*mss1 for mss1 <= mss } It is something sort of: if (mss < 1096) return mss*4; if (mss < 1096*2) return 1096*4; return mss*2; (I just scrablled a graph of piece of paper, it is difficult to see or to explain without this) I selected it differently giving more window than it is strictly required. Initial receive window must be large enough to allow sender following to the rfc (or just setting initial cwnd to 2) to send initial burst. But besides that it is arbitrary, so I decided to give slack space of one segment. Actually, the logic was: If mss is low/normal (<=ethernet), set window to receive more than initial burst allowed by rfc under the worst conditions i.e. mss*4. This gives slack space of 1 segment for ethernet frames. For msses slighlty more than ethernet frame, take 3. Try to give slack space of 1 frame again. If mss is huge, force 2*mss. No slack space. Value 1460*3 is really confusing. Minimal one is 1096*2, but besides that it is an arbitrary value. It was meant to be ~4096. 1460*3 is just the magic number from RFC, 1460*3 = 1095*4 is the magic :-), so that I guess hands typed this themselves. -------------------- Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-28[TCP]: Fix init_cwnd calculations in tcp_select_initial_window()David S. Miller
Match it up to what RFC2414 really specifies. Noticed by Rick Jones. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-22[TCP]: Adjust Reno SACK estimate in tcp_fragmentHerbert Xu
Since the introduction of TSO pcount a year ago, it has been possible for tcp_fragment() to cause packets_out to decrease. Prior to that, tcp_retrans_try_collapse() was the only way for that to happen on the retransmission path. When this happens with Reno, it is possible for sasked_out to become invalid because it is only an estimate and not tied to any particular packet on the retransmission queue. Therefore we need to adjust sacked_out as well as left_out in the Reno case. The following patch does exactly that. This bug is pretty difficult to trigger in practice though since you need a SACKless peer with a retransmission that occurs just as the cached MTU value expires. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-19[TCP]: Handle SACK'd packets properly in tcp_fragment().Herbert Xu
The problem is that we're now calling tcp_fragment() in a context where the packets might be marked as SACKED_ACKED or SACKED_RETRANS. This was not possible before as you never retransmitted packets that are so marked. Because of this, we need to adjust sacked_out and retrans_out in tcp_fragment(). This is exactly what the following patch does. We also need to preserve the SACKED_ACKED/SACKED_RETRANS marking if they exist. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-14[TCP]: Compute in_sacked properly when we split up a TSO frame.Herbert Xu
The problem is that the SACK fragmenting code may incorrectly call tcp_fragment() with a length larger than the skb->len. This happens when the skb on the transmit queue completely falls to the LHS of the SACK. And add a BUG() check to tcp_fragment() so we can spot this kind of error more quickly in the future. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-10[TCP]: Fix double adjustment of tp->{lost,left}_out in tcp_fragment().Herbert Xu
There is an extra left_out/lost_out adjustment in tcp_fragment which means that the lost_out accounting is always wrong. This patch removes that chunk of code. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-08[TCP]: Fix off by one in tcp_fragment() "already sent" test.Herbert Xu
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-01[TCP]: Keep TSO enabled even during loss events.David S. Miller
All we need to do is resegment the queue so that we record SACK information accurately. The edges of the SACK blocks guide our resegmenting decisions. With help from Herbert Xu. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[NET]: Implement SKB fast cloning.David S. Miller
Protocols that make extensive use of SKB cloning, for example TCP, eat at least 2 allocations per packet sent as a result. To cut the kmalloc() count in half, we implement a pre-allocation scheme wherein we allocate 2 sk_buff objects in advance, then use a simple reference count to free up the memory at the correct time. Based upon an initial patch by Thomas Graf and suggestions from Herbert Xu. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[NET]: Store skb->timestamp as offset to a base timestampPatrick McHardy
Reduces skb size by 8 bytes on 64-bit. Signed-off-by: Patrick McHardy <kaber@trash.net> 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>
2005-08-29[NET]: Just move the inet_connection_sock function from tcp sourcesArnaldo Carvalho de Melo
Completing the previous changeset, this also generalises tcp_v4_synq_add, renaming it to inet_csk_reqsk_queue_hash_add, already geing used in the DCCP tree, which I plan to merge RSN. Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[NET]: Introduce inet_connection_sockArnaldo Carvalho de Melo
This creates struct inet_connection_sock, moving members out of struct tcp_sock that are shareable with other INET connection oriented protocols, such as DCCP, that in my private tree already uses most of these members. The functions that operate on these members were renamed, using a inet_csk_ prefix while not being moved yet to a new file, so as to ease the review of these changes. Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[NET]: Kill skb->listDavid S. Miller
Remove the "list" member of struct sk_buff, as it is entirely redundant. All SKB list removal callers know which list the SKB is on, so storing this in sk_buff does nothing other than taking up some space. Two tricky bits were SCTP, which I took care of, and two ATM drivers which Francois Romieu <romieu@fr.zoreil.com> fixed up. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
2005-08-23[TCP]: Do TSO deferral even if tail SKB can go out now.Dmitry Yusupov
If the tail SKB fits into the window, it is still benefitical to defer until the goal percentage of the window is available. This give the application time to feed more data into the send queue and thus results in larger TSO frames going out. Patch from Dmitry Yusupov <dima@neterion.com>. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-16[TCP]: Fix bug #5070: kernel BUG at net/ipv4/tcp_output.c:864Herbert Xu
1) We send out a normal sized packet with TSO on to start off. 2) ICMP is received indicating a smaller MTU. 3) We send the current sk_send_head which needs to be fragmented since it was created before the ICMP event. The first fragment is then sent out. At this point the remaining fragment is allocated by tcp_fragment. However, its size is padded to fit the L1 cache-line size therefore creating tail-room up to 124 bytes long. This fragment will also be sitting at sk_send_head. 4) tcp_sendmsg is called again and it stores data in the tail-room of of the fragment. 5) tcp_push_one is called by tcp_sendmsg which then calls tso_fragment since the packet as a whole exceeds the MTU. At this point we have a packet that has data in the head area being fed to tso_fragment which bombs out. My take on this is that we shouldn't ever call tcp_fragment on a TSO socket for a packet that is yet to be transmitted since this creates a packet on sk_send_head that cannot be extended. So here is a patch to change it so that tso_fragment is always used in this case. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-10[TCP]: Adjust {p,f}ackets_out correctly in tcp_retransmit_skb()Herbert Xu
Well I've only found one potential cause for the assertion failure in tcp_mark_head_lost. First of all, this can only occur if cnt > 1 since tp->packets_out is never zero here. If it did hit zero we'd have much bigger problems. So cnt is equal to fackets_out - reordering. Normally fackets_out is less than packets_out. The only reason I've found that might cause fackets_out to exceed packets_out is if tcp_fragment is called from tcp_retransmit_skb with a TSO skb and the current MSS is greater than the MSS stored in the TSO skb. This might occur as the result of an expiring dst entry. In that case, packets_out may decrease (line 1380-1381 in tcp_output.c). However, fackets_out is unchanged which means that it may in fact exceed packets_out. Previously tcp_retrans_try_collapse was the only place where packets_out can go down and it takes care of this by decrementing fackets_out. So we should make sure that fackets_out is reduced by an appropriate amount here as well. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-04[PATCH] tcp: fix TSO cwnd caching bugHerbert Xu
tcp_write_xmit caches the cwnd value indirectly in cwnd_quota. When tcp_transmit_skb reduces the cwnd because of tcp_enter_cwr, the cached value becomes invalid. This patch ensures that the cwnd value is always reread after each tcp_transmit_skb call. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-04[PATCH] tcp: fix TSO sizing bugsDavid S. Miller
MSS changes can be lost since we preemptively initialize the tso_segs count for an SKB before we %100 commit to sending it out. So, by the time we send it out, the tso_size information can be stale due to PMTU events. This mucks up all of the logic in our send engine, and can even result in the BUG() triggering in tcp_tso_should_defer(). Another problem we have is that we're storing the tp->mss_cache, not the SACK block normalized MSS, as the tso_size. That's wrong too. Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>