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2008-12-25netns: igmp: make /proc/net/{igmp,mcfilter} per netnsAlexey Dobriyan1-9/+40
This patch makes the followinf proc entries per-netns: /proc/net/igmp /proc/net/mcfilter Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Daniel Lezcano <dlezcano@fr.ibm.com> Acked-by: Benjamin Thery <benjamin.thery@bull.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-25netns: igmp: allow IPPROTO_IGMP sockets in netnsAlexey Dobriyan1-0/+1
Looks like everything is already ready. Required for ebtables(8) for one thing. Also, required for ipmr per-netns (coming soon). (Benjamin) Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Benjamin Thery <benjamin.thery@bull.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-18tcp: Stop scaring users with "treason uncloaked!"Matt Mackall1-2/+2
The original message was unhelpful and extremely alarming to our poor users, despite its charm. Make it less frightening. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-16ipmr: merge common codeIlpo Järvinen1-64/+39
Also removes redundant skb->len < x check which can't be true once pskb_may_pull(skb, x) succeeded. $ diff-funcs pim_rcv ipmr.c ipmr.c pim_rcv_v1 --- ipmr.c:pim_rcv() +++ ipmr.c:pim_rcv_v1() @@ -1,22 +1,27 @@ -static int pim_rcv(struct sk_buff * skb) +int pim_rcv_v1(struct sk_buff * skb) { - struct pimreghdr *pim; + struct igmphdr *pim; struct iphdr *encap; struct net_device *reg_dev = NULL; if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap))) goto drop; - pim = (struct pimreghdr *)skb_transport_header(skb); - if (pim->type != ((PIM_VERSION<<4)|(PIM_REGISTER)) || - (pim->flags&PIM_NULL_REGISTER) || - (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 && - csum_fold(skb_checksum(skb, 0, skb->len, 0)))) + pim = igmp_hdr(skb); + + if (!mroute_do_pim || + skb->len < sizeof(*pim) + sizeof(*encap) || + pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER) goto drop; - /* check if the inner packet is destined to mcast group */ encap = (struct iphdr *)(skb_transport_header(skb) + - sizeof(struct pimreghdr)); + sizeof(struct igmphdr)); + /* + Check that: + a. packet is really destinted to a multicast group + b. packet is not a NULL-REGISTER + c. packet is not truncated + */ if (!ipv4_is_multicast(encap->daddr) || encap->tot_len == 0 || ntohs(encap->tot_len) + sizeof(*pim) > skb->len) @@ -40,9 +45,9 @@ skb->ip_summed = 0; skb->pkt_type = PACKET_HOST; dst_release(skb->dst); + skb->dst = NULL; reg_dev->stats.rx_bytes += skb->len; reg_dev->stats.rx_packets++; - skb->dst = NULL; nf_reset(skb); netif_rx(skb); dev_put(reg_dev); $ codiff net/ipv4/ipmr.o.old net/ipv4/ipmr.o.new net/ipv4/ipmr.c: pim_rcv_v1 | -283 pim_rcv | -284 2 functions changed, 567 bytes removed net/ipv4/ipmr.c: __pim_rcv | +307 1 function changed, 307 bytes added net/ipv4/ipmr.o.new: 3 functions changed, 307 bytes added, 567 bytes removed, diff: -260 (Tested on x86_64). It seems that pimlen arg could be left out as well and eq-sizedness of structs trapped with BUILD_BUG_ON but I don't think that's more than a cosmetic flaw since there aren't that many args anyway. Compile tested. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-15tcp: Add GRO supportHerbert Xu3-0/+137
This patch adds the TCP-specific portion of GRO. The criterion for merging is extremely strict (the TCP header must match exactly apart from the checksum) so as to allow refragmentation. Otherwise this is pretty much identical to LRO, except that we support the merging of ECN packets. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-15ipv4: Add GRO infrastructureHerbert Xu1-0/+97
This patch adds GRO support for IPv4. The criteria for merging is more stringent than LRO, in particular, we require all fields in the IP header to be identical except for the length, ID and checksum. In addition, the ID must form an arithmetic sequence with a difference of one. The ID requirement might seem overly strict, however, most hardware TSO solutions already obey this rule. Linux itself also obeys this whether GSO is in use or not. In future we could relax this rule by storing the IDs (or rather making sure that we don't drop them when pulling the aggregate skb's tail). Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-15Merge branch 'master' of ↵David S. Miller2-71/+11
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/e1000e/ich8lan.c
2008-12-15netfilter: update rwlock initialization for nat_tableSteven Rostedt1-1/+1
The commit e099a173573ce1ba171092aee7bb3c72ea686e59 (netfilter: netns nat: per-netns NAT table) renamed the nat_table from __nat_table to nat_table without updating the __RW_LOCK_UNLOCKED(__nat_table.lock). Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-14icsk: join error paths using gotoIlpo Järvinen1-9/+10
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-09tcp: tcp_vegas cong avoid fix Doug Leith1-70/+10
This patch addresses a book-keeping issue in tcp_vegas.c. At present tcp_vegas does separate book-keeping of cwnd based on packet sequence numbers. A mismatch can develop between this book-keeping and tp->snd_cwnd due, for example, to delayed acks acking multiple packets. When vegas transitions to reno operation (e.g. following loss), then this mismatch leads to incorrect behaviour (akin to a cwnd backoff). This seems mostly to affect operation at low cwnds where delayed acking can lead to a significant fraction of cwnd being covered by a single ack, leading to the book-keeping mismatch. This patch modifies the congestion avoidance update to avoid the need for separate book-keeping while leaving vegas congestion avoidance functionally unchanged. A secondary advantage of this modification is that the use of fixed-point (via V_PARAM_SHIFT) and 64 bit arithmetic is no longer necessary, simplifying the code. Some example test measurements with the patched code (confirming no functional change in the congestion avoidance algorithm) can be seen at: http://www.hamilton.ie/doug/vegaspatch/ Signed-off-by: Doug Leith <doug.leith@nuim.ie> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-05tcp: fix tso_should_defer in 64bitIlpo Järvinen1-1/+1
Since jiffies is unsigned long, the types get expanded into that and after long enough time the difference will therefore always be > 1 (and that probably happens near boot as well as iirc the first jiffies wrap is scheduler close after boot to find out problems related to that early). This was originally noted by Bill Fink in Dec'07 but nobody never ended fixing it. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-05tcp: use tcp_write_xmit also in tcp_push_oneIlpo Järvinen1-37/+17
tcp_minshall_update is not significant difference since it only checks for not full-sized skb which is BUG'ed on the push_one path anyway. tcp_snd_test is tcp_nagle_test+tcp_cwnd_test+tcp_snd_wnd_test, just the order changed slightly. net/ipv4/tcp_output.c: tcp_snd_test | -89 tcp_mss_split_point | -91 tcp_may_send_now | +53 tcp_cwnd_validate | -98 tso_fragment | -239 __tcp_push_pending_frames | -1340 tcp_push_one | -146 7 functions changed, 53 bytes added, 2003 bytes removed, diff: -1950 net/ipv4/tcp_output.c: tcp_write_xmit | +1772 1 function changed, 1772 bytes added, diff: +1772 tcp_output.o.new: 8 functions changed, 1825 bytes added, 2003 bytes removed, diff: -178 Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-05Merge branch 'master' of ↵David S. Miller2-12/+12
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/wireless/iwlwifi/iwl-core.c drivers/net/wireless/iwlwifi/iwl-sta.c
2008-12-05tcp: move some parts from tcp_write_xmitIlpo Järvinen1-11/+12
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-05tcp: share code through function, not through copy-paste. :-)Ilpo Järvinen1-7/+10
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-05tcp: drop tcp_bound_rto, merge content of it tcp_set_rtoIlpo Järvinen1-9/+3
Both are called by the same sites. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-05tcp: no need to pass prev skb around, reduces arg pressureIlpo Järvinen1-5/+4
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-05tcp: introduce struct tcp_sacktag_state to reduce arg pressureIlpo Järvinen1-71/+74
There are just too many args to some sacktag functions. This idea was first proposed by David S. Miller around a year ago, and the current situation is much worse that what it was back then. tcp_sacktag_one can be made a bit simpler by returning the new sacked (it can be achieved with a single variable though the previous code "caching" sacked into a local variable and therefore it is not exactly equal but the results will be the same). codiff on x86_64 tcp_sacktag_one | -15 tcp_shifted_skb | -50 tcp_match_skb_to_sack | -1 tcp_sacktag_walk | -64 tcp_sacktag_write_queue | -59 tcp_urg | +1 tcp_event_data_recv | -1 7 functions changed, 1 bytes added, 190 bytes removed, diff: -189 Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-05tcp: make mtu probe failure to not break gso'ed skbs unnecessarilyIlpo Järvinen1-12/+7
I noticed that since skb->len has nothing to do with actual segment length with gso, we need to figure it out separately, reuse a function from the recent shifting stuff (generalize it). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-05tcp: Fix thinko making the not-shiftable to cover S|R as wellIlpo Järvinen1-1/+1
S|R won't result in S if just SACK is received. DSACK is another story (but it is covered correctly already). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-05tcp: force mss equality with the next skb too.Ilpo Järvinen1-5/+4
Also make if-goto forest nicer looking. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-04tcp: tcp_vegas ssthresh bug fixDoug Leith1-0/+2
This patch fixes a bug in tcp_vegas.c. At the moment this code leaves ssthresh untouched. However, this means that the vegas congestion control algorithm is effectively unable to reduce cwnd below the ssthresh value (if the vegas update lowers the cwnd below ssthresh, then slow start is activated to raise it back up). One example where this matters is when during slow start cwnd overshoots the link capacity and a flow then exits slow start with ssthresh set to a value above where congestion avoidance would like to adjust it. Signed-off-by: Doug Leith <doug.leith@nuim.ie> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-03net: /proc/net/ip_mr_cache, display Iif as a signed shortBenjamin Thery1-1/+1
Today, iproute2 fails to show multicast forwarding unresolved cache entries while scanning /proc/net/ip_mr_cache. Indeed, it expects to see -1 in 'Iif' column to identify unresolved entries but the kernel outputs 65535. It's a signed/unsigned issue: 'Iif', the source interface, is retrieved from member mfc_parent in struct mfc_cache. mfc_parent is a vifi_t: unsigned short, but is displayed in ipmr_mfc_seq_show() as "%-3d", signed integer. In unresolevd entries, the 65535 value (0xFFFF) comes from this define: #define ALL_VIFS ((vifi_t)(-1)) That may explains why the guy who added support for this in iproute2 thought a -1 should be expected. I don't know if this must be fixed in kernel or in iproute2. Who is right? What is the correct API? How was it designed originally? I let you decide if it should goes in the kernel or be fixed in iproute2. Signed-off-by: Benjamin Thery <benjamin.thery@bull.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-03net: fix /proc/net/ip_mr_cache display - V2Benjamin Thery1-5/+11
/proc/net/ip_mr_cache and /proc/net/ip6_mr_cache displays garbage when showing unresolved mfc_cache entries. [root@qemu tests]# cat /proc/net/ip_mr_cache Group Origin Iif Pkts Bytes Wrong Oifs 014C00EF 010014AC 1 10 10050 0 2:1 3:1 024C00EF 010014AC 65535 514 2 -559067475 The first line is correct. It is a resolved cache entry, 10 packets used it... The second line represents an unresolved entry, and the columns Pkts(4th), Bytes(5th) and Wrong(6th) just show garbage. In struct mfc_cache, there's an union to store data for resolved and unresolved cases. And what ipmr_mfc_seq_show() is printing in these columns for the unresolved entries is some bytes from mfc_cache.mfc_un.res. Bad. (eg. In our case -559067475 is in fact 0xdead4ead which is the spinlock magic from mfc_cache.mfc_un.unres.unresolved.lock.magic). This patch replaces the garbage data written in these columns for the unresolved entries by '0' (zeros) which is more correct. This change doesn't break the ABI. Also, mfc->mfc_un.res.pkt, mfc->mfc_un.res.bytes, mfc->mfc_un.res.wrong_if are unsigned long. It applies on top of net-next-2.6. The patch for net-2.6 is slightly different because of the NIP6_FMT to %pI6 conversion that was made in the seq_printf. Changelog: ========== V2: * Instead of breaking the ABI by suppressing the columns that have no meaning for unresolved entries, fill them with 0 values. Signed-off-by: Benjamin Thery <benjamin.thery@bull.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-03tcp: make urg+gso work for real this timeIlpo Järvinen1-12/+10
I should have noticed this earlier... :-) The previous solution to URG+GSO/TSO will cause SACK block tcp_fragment to do zig-zig patterns, or even worse, a steep downward slope into packet counting because each skb pcount would be truncated to pcount of 2 and then the following fragments of the later portion would restore the window again. Basically this reverts "tcp: Do not use TSO/GSO when there is urgent data" (33cf71cee1). It also removes some unnecessary code from tcp_current_mss that didn't work as intented either (could be that something was changed down the road, or it might have been broken since the dawn of time) because it only works once urg is already written while this bug shows up starting from ~64k before the urg point. The retransmissions already are split to mss sized chunks, so only new data sending paths need splitting in case they have a segment otherwise suitable for gso/tso. The actually check can be improved to be more narrow but since this is late -rc already, I'll postpone thinking the more fine-grained things. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-01net: percpu_counter_inc() should not be called in BH-disabled sectionEric Dumazet1-2/+2
Based upon a lockdep report by Alexey Dobriyan. I checked all per_cpu_counter_xxx() usages in network tree, and I think all call sites are BH enabled except one in inet_csk_listen_stop(). commit dd24c00191d5e4a1ae896aafe33c6b8095ab4bd1 (net: Use a percpu_counter for orphan_count) replaced atomic_t orphan_count to a percpu_counter. atomic_inc()/atomic_dec() can be called from any context, while percpu_counter_xxx() should be called from a consistent state. For orphan_count, this context can be the BH-enabled one. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-28Merge branch 'master' of ↵David S. Miller4-41/+13
git://git.kernel.org/pub/scm/linux/kernel/git/kaber/nf-next-2.6 Conflicts: net/netfilter/nf_conntrack_netlink.c
2008-11-26Merge branch 'master' of ↵David S. Miller1-2/+5
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/hp-plus.c drivers/net/wireless/ath5k/base.c drivers/net/wireless/ath9k/recv.c net/wireless/reg.c
2008-11-25net: Use a percpu_counter for orphan_countEric Dumazet4-9/+11
Instead of using one atomic_t per protocol, use a percpu_counter for "orphan_count", to reduce cache line contention on heavy duty network servers. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25net: Use a percpu_counter for sockets_allocatedEric Dumazet3-5/+10
Instead of using one atomic_t per protocol, use a percpu_counter for "sockets_allocated", to reduce cache line contention on heavy duty network servers. Note : We revert commit (248969ae31e1b3276fc4399d67ce29a5d81e6fd9 net: af_unix can make unix_nr_socks visbile in /proc), since it is not anymore used after sock_prot_inuse_add() addition Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25netns xfrm: AH/ESP in netns!Alexey Dobriyan2-2/+6
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25netns xfrm: ->get_saddr in netnsAlexey Dobriyan1-2/+3
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25netns xfrm: ->dst_lookup in netnsAlexey Dobriyan1-3/+4
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25netns xfrm: dst garbage-collecting in netnsAlexey Dobriyan1-1/+1
Pass netns pointer to struct xfrm_policy_afinfo::garbage_collect() [This needs more thoughts on what to do with dst_ops] [Currently stub to init_net] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25netns xfrm: lookup in netnsAlexey Dobriyan3-5/+5
Pass netns to xfrm_lookup()/__xfrm_lookup(). For that pass netns to flow_cache_lookup() and resolver callback. Take it from socket or netdevice. Stub DECnet to init_net. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25netns xfrm: state lookup in netnsAlexey Dobriyan3-4/+4
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25netns xfrm: add struct xfrm_state::xs_netAlexey Dobriyan1-1/+1
To avoid unnecessary complications with passing netns around. * set once, very early after allocating * once set, never changes For a while create every xfrm_state in init_net. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25net: udp_unhash() can test if sk is hashedEric Dumazet1-8/+10
Impact: Optimization Like done in inet_unhash(), we can avoid taking a chain lock if socket is not hashed in udp_unhash() Triggered by close(socket(AF_INET, SOCK_DGRAM, 0)); Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25tcp: tcp_limit_reno_sacked can become staticIlpo Järvinen1-1/+1
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25netfilter: nfmark routing in OUTPUT, mangle, NFQUEUEEric Leblond1-0/+3
This patch let nfmark to be evaluated for routing decision for OUTPUT packet, in mangle table, when process paquet in NFQUEUE Until now, only change (in NFQUEUE process) on fields src_addr, dest_addr and tos could make netfilter to reevalute the routing. From: Laurent Licour <laurent@licour.com> Signed-off-by: Eric Leblond <eric@inl.fr> Signed-off-by: Patrick McHardy <kaber@trash.net>
2008-11-25xfrm: remove useless forward declarationsAlexey Dobriyan1-2/+0
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25ah4/ah6: remove useless NULL assignmentsAlexey Dobriyan1-2/+0
struct will be kfreed in a moment, so... Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-24tcp: add some mibs to track collapsingIlpo Järvinen2-0/+7
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-24tcp: Make shifting not clear the hintsIlpo Järvinen1-2/+14
The earlier version was just very basic one which is "playing safe" by always clearing the hints. However, clearing of a hint is extremely costly operation with large windows, so it must be avoided at all cost whenever possible, there is a way with shifting too achieve not-clearing. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-24tcp: Try to restore large SKBs while SACK processingIlpo Järvinen1-7/+249
During SACK processing, most of the benefits of TSO are eaten by the SACK blocks that one-by-one fragment SKBs to MSS sized chunks. Then we're in problems when cleanup work for them has to be done when a large cumulative ACK comes. Try to return back to pre-split state already while more and more SACK info gets discovered by combining newly discovered SACK areas with the previous skb if that's SACKed as well. This approach has a number of benefits: 1) The processing overhead is spread more equally over the RTT 2) Write queue has less skbs to process (affect everything which has to walk in the queue past the sacked areas) 3) Write queue is consistent whole the time, so no other parts of TCP has to be aware of this (this was not the case with some other approach that was, well, quite intrusive all around). 4) Clean_rtx_queue can release most of the pages using single put_page instead of previous PAGE_SIZE/mss+1 calls In case a hole is fully filled by the new SACK block, we attempt to combine the next skb too which allows construction of skbs that are even larger than what tso split them to and it handles hole per on every nth patterns that often occur during slow start overshoot pretty nicely. Though this to be really useful also a retransmission would have to get lost since cumulative ACKs advance one hole at a time in the most typical case. TODO: handle upwards only merging. That should be rather easy when segment is fully sacked but I'm leaving that as future work item (it won't make very large difference anyway since this current approach already covers quite a lot of normal cases). I was earlier thinking of some sophisticated way of tracking timestamps of the first and the last segment but later on realized that it won't be that necessary at all to store the timestamp of the last segment. The cases that can occur are basically either: 1) ambiguous => no sensible measurement can be taken anyway 2) non-ambiguous is due to reordering => having the timestamp of the last segment there is just skewing things more off than does some good since the ack got triggered by one of the holes (besides some substle issues that would make determining right hole/skb even harder problem). Anyway, it has nothing to do with this change then. I choose to route some abnormal looking cases with goto noop, some could be handled differently (eg., by stopping the walking at that skb but again). In general, they either shouldn't happen at all or are rare enough to make no difference in practice. In theory this change (as whole) could cause some macroscale regression (global) because of cache misses that are taken over the round-trip time but it gets very likely better because of much less (local) cache misses per other write queue walkers and the big recovery clearing cumulative ack. Worth to note that these benefits would be very easy to get also without TSO/GSO being on as long as the data is in pages so that we can merge them. Currently I won't let that happen because DSACK splitting at fragment that would mess up pcounts due to sk_can_gso in tcp_set_skb_tso_segs. Once DSACKs fragments gets avoided, we have some conditions that can be made less strict. TODO: I will probably have to convert the excessive pointer passing to struct sacktag_state... :-) My testing revealed that considerable amount of skbs couldn't be shifted because they were cloned (most likely still awaiting tx reclaim)... [The rest is considering future work instead since I got repeatably EFAULT to tcpdump's recvfrom when I added pskb_expand_head to deal with clones, so I separated that into another, later patch] ...To counter that, I gave up on the fifth advantage: 5) When growing previous SACK block, less allocs for new skbs are done, basically a new alloc is needed only when new hole is detected and when the previous skb runs out of frags space ...which now only happens of if reclaim is fast enough to dispose the clone before the SACK block comes in (the window is RTT long), otherwise we'll have to alloc some. With clones being handled I got these numbers (will be somewhat worse without that), taken with fine-grained mibs: TCPSackShifted 398 TCPSackMerged 877 TCPSackShiftFallback 320 TCPSACKCOLLAPSEFALLBACKGSO 0 TCPSACKCOLLAPSEFALLBACKSKBBITS 0 TCPSACKCOLLAPSEFALLBACKSKBDATA 0 TCPSACKCOLLAPSEFALLBACKBELOW 0 TCPSACKCOLLAPSEFALLBACKFIRST 1 TCPSACKCOLLAPSEFALLBACKPREVBITS 318 TCPSACKCOLLAPSEFALLBACKMSS 1 TCPSACKCOLLAPSEFALLBACKNOHEAD 0 TCPSACKCOLLAPSEFALLBACKSHIFT 0 TCPSACKCOLLAPSENOOPSEQ 0 TCPSACKCOLLAPSENOOPSMALLPCOUNT 0 TCPSACKCOLLAPSENOOPSMALLLEN 0 TCPSACKCOLLAPSEHOLE 12 Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-24tcp: make tcp_sacktag_one able to handle partial skb tooIlpo Järvinen1-15/+17
This is preparatory work for SACK combiner patch which may have to count TCP state changes for only a part of the skb because it will intentionally avoids splitting skb to SACKed and not sacked parts. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-24tcp: Make SACK code to split only at mss boundariesIlpo Järvinen1-4/+23
Sadly enough, this adds possible divide though we try to avoid it by checking one mss as common case. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-24tcp: more aggressive skippingIlpo Järvinen1-1/+1
I knew already when rewriting the sacktag that this condition was too conservative, change it now since it prevent lot of useless work (especially in the sack shifter decision code that is being added by a later patch). This shouldn't change anything really, just save some processing regardless of the shifter. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-24tcp: move tcp_simple_retransmit to tcp_inputIlpo Järvinen2-51/+52
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-24tcp: collapse more than two on retransmissionIlpo Järvinen1-37/+59
I always had thought that collapsing up to two at a time was intentional decision to avoid excessive processing if 1 byte sized skbs are to be combined for a full mtu, and consecutive retransmissions would make the size of the retransmittee double each round anyway, but some recent discussion made me to understand that was not the case. Thus make collapse work more and wait less. It would be possible to take advantage of the shifting machinery (added in the later patch) in the case of paged data but that can be implemented on top of this change. tcp_skb_is_last check is now provided by the loop. I tested a bit (ss-after-idle-off, fill 4096x4096B xfer, 10s sleep + 4096 x 1byte writes while dropping them for some a while with netem): . 16774097:16775545(1448) ack 1 win 46 . 16775545:16776993(1448) ack 1 win 46 . ack 16759617 win 2399 P 16776993:16777217(224) ack 1 win 46 . ack 16762513 win 2399 . ack 16765409 win 2399 . ack 16768305 win 2399 . ack 16771201 win 2399 . ack 16774097 win 2399 . ack 16776993 win 2399 . ack 16777217 win 2399 P 16777217:16777257(40) ack 1 win 46 . ack 16777257 win 2399 P 16777257:16778705(1448) ack 1 win 46 P 16778705:16780153(1448) ack 1 win 46 FP 16780153:16781313(1160) ack 1 win 46 . ack 16778705 win 2399 . ack 16780153 win 2399 F 1:1(0) ack 16781314 win 2399 While without drop-all period I get this: . 16773585:16775033(1448) ack 1 win 46 . ack 16764897 win 9367 . ack 16767793 win 9367 . ack 16770689 win 9367 . ack 16773585 win 9367 . 16775033:16776481(1448) ack 1 win 46 P 16776481:16777217(736) ack 1 win 46 . ack 16776481 win 9367 . ack 16777217 win 9367 P 16777217:16777218(1) ack 1 win 46 P 16777218:16777219(1) ack 1 win 46 P 16777219:16777220(1) ack 1 win 46 ... P 16777247:16777248(1) ack 1 win 46 . ack 16777218 win 9367 . ack 16777219 win 9367 ... . ack 16777233 win 9367 . ack 16777248 win 9367 P 16777248:16778696(1448) ack 1 win 46 P 16778696:16780144(1448) ack 1 win 46 FP 16780144:16781313(1169) ack 1 win 46 . ack 16780144 win 9367 F 1:1(0) ack 16781314 win 9367 The window seems to be 30-40 segments, which were successfully combined into: P 16777217:16777257(40) ack 1 win 46 Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-17 04:54:05 +0000