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* tcp: Fix a connect() race with timewait socketsEric Dumazet2009-12-081-0/+2
| | | | | | | | | | | | | | | | | | When we find a timewait connection in __inet_hash_connect() and reuse it for a new connection request, we have a race window, releasing bind list lock and reacquiring it in __inet_twsk_kill() to remove timewait socket from list. Another thread might find the timewait socket we already chose, leading to list corruption and crashes. Fix is to remove timewait socket from bind list before releasing the bind lock. Note: This problem happens if sysctl_tcp_tw_reuse is set. Reported-by: kapil dakhane <kdakhane@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Fix a connect() race with timewait socketsEric Dumazet2009-12-081-6/+16
| | | | | | | | | | | | | First patch changes __inet_hash_nolisten() and __inet6_hash() to get a timewait parameter to be able to unhash it from ehash at same time the new socket is inserted in hash. This makes sure timewait socket wont be found by a concurrent writer in __inet_check_established() Reported-by: kapil dakhane <kdakhane@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: connect() race with timewait reuseEric Dumazet2009-12-031-3/+7
| | | | | | | | | | | | | | | | | | | | | Its currently possible that several threads issuing a connect() find the same timewait socket and try to reuse it, leading to list corruptions. Condition for bug is that these threads bound their socket on same address/port of to-be-find timewait socket, and connected to same target. (SO_REUSEADDR needed) To fix this problem, we could unhash timewait socket while holding ehash lock, to make sure lookups/changes will be serialized. Only first thread finds the timewait socket, other ones find the established socket and return an EADDRNOTAVAIL error. This second version takes into account Evgeniy's review and makes sure inet_twsk_put() is called outside of locked sections. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: use net_eq to compare netsOctavian Purdila2009-11-251-1/+2
| | | | | | | | | | | | | | | | | | | | | | | Generated with the following semantic patch @@ struct net *n1; struct net *n2; @@ - n1 == n2 + net_eq(n1, n2) @@ struct net *n1; struct net *n2; @@ - n1 != n2 + !net_eq(n1, n2) applied over {include,net,drivers/net}. Signed-off-by: Octavian Purdila <opurdila@ixiacom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: rename some inet_sock fieldsEric Dumazet2009-10-181-16/+18
| | | | | | | | | | | | | | | | In order to have better cache layouts of struct sock (separate zones for rx/tx paths), we need this preliminary patch. Goal is to transfert fields used at lookup time in the first read-mostly cache line (inside struct sock_common) and move sk_refcnt to a separate cache line (only written by rx path) This patch adds inet_ prefix to daddr, rcv_saddr, dport, num, saddr, sport and id fields. This allows a future patch to define these fields as macros, like sk_refcnt, without name clashes. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: replace ehash_size by ehash_maskEric Dumazet2009-10-131-1/+1
| | | | | | | | Storing the mask (size - 1) instead of the size allows fast path to be a bit faster. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: move bsockets outside of read only beginning of struct inet_hashinfoEric Dumazet2009-02-011-2/+3
| | | | | | | | And switch bsockets to atomic_t since it might be changed in parallel. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: Allowing more than 64k connections and heavily optimize bind(0) time.Evgeniy Polyakov2009-01-211-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With simple extension to the binding mechanism, which allows to bind more than 64k sockets (or smaller amount, depending on sysctl parameters), we have to traverse the whole bind hash table to find out empty bucket. And while it is not a problem for example for 32k connections, bind() completion time grows exponentially (since after each successful binding we have to traverse one bucket more to find empty one) even if we start each time from random offset inside the hash table. So, when hash table is full, and we want to add another socket, we have to traverse the whole table no matter what, so effectivelly this will be the worst case performance and it will be constant. Attached picture shows bind() time depending on number of already bound sockets. Green area corresponds to the usual binding to zero port process, which turns on kernel port selection as described above. Red area is the bind process, when number of reuse-bound sockets is not limited by 64k (or sysctl parameters). The same exponential growth (hidden by the green area) before number of ports reaches sysctl limit. At this time bind hash table has exactly one reuse-enbaled socket in a bucket, but it is possible that they have different addresses. Actually kernel selects the first port to try randomly, so at the beginning bind will take roughly constant time, but with time number of port to check after random start will increase. And that will have exponential growth, but because of above random selection, not every next port selection will necessary take longer time than previous. So we have to consider the area below in the graph (if you could zoom it, you could find, that there are many different times placed there), so area can hide another. Blue area corresponds to the port selection optimization. This is rather simple design approach: hashtable now maintains (unprecise and racely updated) number of currently bound sockets, and when number of such sockets becomes greater than predefined value (I use maximum port range defined by sysctls), we stop traversing the whole bind hash table and just stop at first matching bucket after random start. Above limit roughly corresponds to the case, when bind hash table is full and we turned on mechanism of allowing to bind more reuse-enabled sockets, so it does not change behaviour of other sockets. Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net> Tested-by: Denys Fedoryschenko <denys@visp.net.lb> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Make sure BHs are disabled in sock_prot_inuse_add()Eric Dumazet2008-11-241-1/+1
| | | | | | | | | | | | | The rule of calling sock_prot_inuse_add() is that BHs must be disabled. Some new calls were added where this was not true and this tiggers warnings as reported by Ilpo. Fix this by adding explicit BH disabling around those call sites, or moving sock_prot_inuse_add() call inside an existing BH disabled section. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Convert TCP/DCCP listening hash tables to use RCUEric Dumazet2008-11-231-74/+74
| | | | | | | | | | | | | | | | | | | | | | This is the last step to be able to perform full RCU lookups in __inet_lookup() : After established/timewait tables, we add RCU lookups to listening hash table. The only trick here is that a socket of a given type (TCP ipv4, TCP ipv6, ...) can now flight between two different tables (established and listening) during a RCU grace period, so we must use different 'nulls' end-of-chain values for two tables. We define a large value : #define LISTENING_NULLS_BASE (1U << 29) So that slots in listening table are guaranteed to have different end-of-chain values than slots in established table. A reader can still detect it finished its lookup in the right chain. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: convert TCP/DCCP ehash rwlocks to spinlocksEric Dumazet2008-11-201-11/+10
| | | | | | | | | | | | Now TCP & DCCP use RCU lookups, we can convert ehash rwlocks to spinlocks. /proc/net/tcp and other seq_file 'readers' can safely be converted to 'writers'. This should speedup writers, since spin_lock()/spin_unlock() only use one atomic operation instead of two for write_lock()/write_unlock() Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: listening_hash get a spinlock per bucketEric Dumazet2008-11-201-55/+31
| | | | | | | | | | | | | This patch prepares RCU migration of listening_hash table for TCP/DCCP protocols. listening_hash table being small (32 slots per protocol), we add a spinlock for each slot, instead of a single rwlock for whole table. This should reduce hold time of readers, and writers concurrency. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Convert TCP & DCCP hash tables to use RCU / hlist_nullsEric Dumazet2008-11-161-23/+55
| | | | | | | | | | | | | | | | | | | | | | | RCU was added to UDP lookups, using a fast infrastructure : - sockets kmem_cache use SLAB_DESTROY_BY_RCU and dont pay the price of call_rcu() at freeing time. - hlist_nulls permits to use few memory barriers. This patch uses same infrastructure for TCP/DCCP established and timewait sockets. Thanks to SLAB_DESTROY_BY_RCU, no slowdown for applications using short lived TCP connections. A followup patch, converting rwlocks to spinlocks will even speedup this case. __inet_lookup_established() is pretty fast now we dont have to dirty a contended cache line (read_lock/read_unlock) Only established and timewait hashtable are converted to RCU (bind table and listen table are still using traditional locking) Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: ib_net pointer should depends on CONFIG_NET_NSEric Dumazet2008-11-121-3/+3
| | | | | | | | We can shrink size of "struct inet_bind_bucket" by 50%, using read_pnet() and write_pnet() Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: convert BUG_TRAP to generic WARN_ONIlpo Järvinen2008-07-251-4/+4
| | | | | | | | | | | | | | Removes legacy reinvent-the-wheel type thing. The generic machinery integrates much better to automated debugging aids such as kerneloops.org (and others), and is unambiguous due to better naming. Non-intuively BUG_TRAP() is actually equal to WARN_ON() rather than BUG_ON() though some might actually be promoted to BUG_ON() but I left that to future. I could make at least one BUILD_BUG_ON conversion. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* mib: add net to NET_INC_STATS_BHPavel Emelyanov2008-07-161-2/+2
| | | | | Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: add struct net argument to inet_ehashfnPavel Emelyanov2008-06-161-3/+3
| | | | | | | | | Although this hash takes addresses into account, the ehash chains can also be too long when, for instance, communications via lo occur. So, prepare the inet_hashfn to take struct net into account. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: add struct net argument to inet_lhashfnPavel Emelyanov2008-06-161-1/+1
| | | | | | | | | Listening-on-one-port sockets in many namespaces produce long chains in the listening_hash-es, so prepare the inet_lhashfn to take struct net into account. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: add struct net argument to inet_bhashfnPavel Emelyanov2008-06-161-4/+7
| | | | | | | | | Binding to some port in many namespaces may create too long chains in bhash-es, so prepare the hashfn to take struct net into account. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [INET]: Uninline the __inet_inherit_port call.Pavel Emelyanov2008-04-171-0/+16
| | | | | | | | | | | This deblats ~200 bytes when ipv6 and dccp are 'y'. Besides, this will ease compilation issues for patches I'm working on to make inet hash tables more scalable wrt net namespaces. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NETNS]: Add netns refcnt debug for inet bind buckets.Denis V. Lunev2008-04-161-1/+2
| | | | | Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [SOCK][NETNS]: Add a struct net argument to sock_prot_inuse_add and _get.Pavel Emelyanov2008-03-311-4/+4
| | | | | | | | | | | | | | This counter is about to become per-proto-and-per-net, so we'll need two arguments to determine which cell in this "table" to work with. All the places, but proc already pass proper net to it - proc will be tuned a bit later. Some indentation with spaces in proc files is done to keep the file coding style consistent. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET] NETNS: Omit namespace comparision without CONFIG_NET_NS.YOSHIFUJI Hideaki2008-03-261-2/+2
| | | | | | | | | | | Introduce an inline net_eq() to compare two namespaces. Without CONFIG_NET_NS, since no namespace other than &init_net exists, it is always 1. We do not need to convert 1) inline vs inline and 2) inline vs &init_net comparisons. Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
* [NET] NETNS: Omit sock->sk_net without CONFIG_NET_NS.YOSHIFUJI Hideaki2008-03-261-4/+4
| | | | | | | | | Introduce per-sock inlines: sock_net(), sock_net_set() and per-inet_timewait_sock inlines: twsk_net(), twsk_net_set(). Without CONFIG_NET_NS, no namespace other than &init_net exists. Let's explicitly define them to help compiler optimizations. Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
* [SOCK]: Add udp_hash member to struct proto.Pavel Emelyanov2008-03-221-4/+4
| | | | | | | | | | | | | | | | | Inspired by the commit ab1e0a13 ([SOCK] proto: Add hashinfo member to struct proto) from Arnaldo, I made similar thing for UDP/-Lite IPv4 and -v6 protocols. The result is not that exciting, but it removes some levels of indirection in udpxxx_get_port and saves some space in code and text. The first step is to union existing hashinfo and new udp_hash on the struct proto and give a name to this union, since future initialization of tcpxxx_prot, dccp_vx_protinfo and udpxxx_protinfo will cause gcc warning about inability to initialize anonymous member this way. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [INET]: Unexport inet_listen_wlockAdrian Bunk2008-02-131-2/+0
| | | | | | | This patch removes the no longer used EXPORT_SYMBOL(inet_listen_wlock). Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [INET]: Unexport __inet_hash_connectAdrian Bunk2008-02-131-1/+0
| | | | | | | This patch removes the unused EXPORT_SYMBOL_GPL(__inet_hash_connect). Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [INET]: Fix accidentally broken inet(6)_hash_connect's port offset calculations.Pavel Emelyanov2008-02-051-3/+3
| | | | | | | | | | | | | | | The port offset calculations depend on the protocol family, but, as Adrian noticed, I broke this logic with the commit 5ee31fc1ecdcbc234c8c56dcacef87c8e09909d8 [INET]: Consolidate inet(6)_hash_connect. Return this logic back, by passing the port offset directly into the consolidated function. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Noticed-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [SOCK] proto: Add hashinfo member to struct protoArnaldo Carvalho de Melo2008-02-031-10/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This way we can remove TCP and DCCP specific versions of sk->sk_prot->get_port: both v4 and v6 use inet_csk_get_port sk->sk_prot->hash: inet_hash is directly used, only v6 need a specific version to deal with mapped sockets sk->sk_prot->unhash: both v4 and v6 use inet_hash directly struct inet_connection_sock_af_ops also gets a new member, bind_conflict, so that inet_csk_get_port can find the per family routine. Now only the lookup routines receive as a parameter a struct inet_hashtable. With this we further reuse code, reducing the difference among INET transport protocols. Eventually work has to be done on UDP and SCTP to make them share this infrastructure and get as a bonus inet_diag interfaces so that iproute can be used with these protocols. net-2.6/net/ipv4/inet_hashtables.c: struct proto | +8 struct inet_connection_sock_af_ops | +8 2 structs changed __inet_hash_nolisten | +18 __inet_hash | -210 inet_put_port | +8 inet_bind_bucket_create | +1 __inet_hash_connect | -8 5 functions changed, 27 bytes added, 218 bytes removed, diff: -191 net-2.6/net/core/sock.c: proto_seq_show | +3 1 function changed, 3 bytes added, diff: +3 net-2.6/net/ipv4/inet_connection_sock.c: inet_csk_get_port | +15 1 function changed, 15 bytes added, diff: +15 net-2.6/net/ipv4/tcp.c: tcp_set_state | -7 1 function changed, 7 bytes removed, diff: -7 net-2.6/net/ipv4/tcp_ipv4.c: tcp_v4_get_port | -31 tcp_v4_hash | -48 tcp_v4_destroy_sock | -7 tcp_v4_syn_recv_sock | -2 tcp_unhash | -179 5 functions changed, 267 bytes removed, diff: -267 net-2.6/net/ipv6/inet6_hashtables.c: __inet6_hash | +8 1 function changed, 8 bytes added, diff: +8 net-2.6/net/ipv4/inet_hashtables.c: inet_unhash | +190 inet_hash | +242 2 functions changed, 432 bytes added, diff: +432 vmlinux: 16 functions changed, 485 bytes added, 492 bytes removed, diff: -7 /home/acme/git/net-2.6/net/ipv6/tcp_ipv6.c: tcp_v6_get_port | -31 tcp_v6_hash | -7 tcp_v6_syn_recv_sock | -9 3 functions changed, 47 bytes removed, diff: -47 /home/acme/git/net-2.6/net/dccp/proto.c: dccp_destroy_sock | -7 dccp_unhash | -179 dccp_hash | -49 dccp_set_state | -7 dccp_done | +1 5 functions changed, 1 bytes added, 242 bytes removed, diff: -241 /home/acme/git/net-2.6/net/dccp/ipv4.c: dccp_v4_get_port | -31 dccp_v4_request_recv_sock | -2 2 functions changed, 33 bytes removed, diff: -33 /home/acme/git/net-2.6/net/dccp/ipv6.c: dccp_v6_get_port | -31 dccp_v6_hash | -7 dccp_v6_request_recv_sock | +5 3 functions changed, 5 bytes added, 38 bytes removed, diff: -33 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NETNS]: Tcp-v4 sockets per-net lookup.Pavel Emelyanov2008-01-311-10/+19
| | | | | | | | | | | Add a net argument to inet_lookup and propagate it further into lookup calls. Plus tune the __inet_check_established. The dccp and inet_diag, which use that lookup functions pass the init_net into them. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NETNS]: Make bind buckets live in net namespaces.Pavel Emelyanov2008-01-311-2/+6
| | | | | | | | | | | | | This tags the inet_bind_bucket struct with net pointer, initializes it during creation and makes a filtering during lookup. A better hashfn, that takes the net into account is to be done in the future, but currently all bind buckets with similar port will be in one hash chain. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [INET]: Consolidate inet(6)_hash_connect.Pavel Emelyanov2008-01-311-11/+21
| | | | | | | | | | | | | | | | | | | These two functions are the same except for what they call to "check_established" and "hash" for a socket. This saves half-a-kilo for ipv4 and ipv6. add/remove: 1/0 grow/shrink: 1/4 up/down: 582/-1128 (-546) function old new delta __inet_hash_connect - 577 +577 arp_ignore 108 113 +5 static.hint 8 4 -4 rt_worker_func 376 372 -4 inet6_hash_connect 584 25 -559 inet_hash_connect 586 25 -561 Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: prot_inuse cleanups and optimizationsEric Dumazet2008-01-281-3/+3
| | | | | | | | | | | | | | | | | | | | 1) Cleanups (all functions are prefixed by sock_prot_inuse) sock_prot_inc_use(prot) -> sock_prot_inuse_add(prot,-1) sock_prot_dec_use(prot) -> sock_prot_inuse_add(prot,-1) sock_prot_inuse() -> sock_prot_inuse_get() New functions : sock_prot_inuse_init() and sock_prot_inuse_free() to abstract pcounter use. 2) if CONFIG_PROC_FS=n, we can zap 'inuse' member from "struct proto", since nobody wants to read the inuse value. This saves 1372 bytes on i386/SMP and some cpu cycles. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: Add some acquires/releases sparse annotations.Eric Dumazet2008-01-281-0/+1
| | | | | | | | | | | | | | | Add __acquires() and __releases() annotations to suppress some sparse warnings. example of warnings : net/ipv4/udp.c:1555:14: warning: context imbalance in 'udp_seq_start' - wrong count at exit net/ipv4/udp.c:1571:13: warning: context imbalance in 'udp_seq_stop' - unexpected unlock Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [INET]: Uninline the __inet_lookup_established function.Pavel Emelyanov2008-01-281-0/+38
| | | | | | | | | | | | | | | | | This is -700 bytes from the net/ipv4/built-in.o add/remove: 1/0 grow/shrink: 1/3 up/down: 340/-1040 (-700) function old new delta __inet_lookup_established - 339 +339 tcp_sacktag_write_queue 2254 2255 +1 tcp_v4_err 1304 973 -331 tcp_v4_rcv 2089 1744 -345 tcp_v4_do_rcv 826 462 -364 Exporting is for dccp module (used via e.g. inet_lookup). Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [INET]: Uninline the __inet_hash function.Pavel Emelyanov2008-01-281-2/+44
| | | | | | | | | | | | | | | | | | | | | | | This one is used in quite many places in the networking code and seems to big to be inline. After the patch net/ipv4/build-in.o loses ~650 bytes: add/remove: 2/0 grow/shrink: 0/5 up/down: 461/-1114 (-653) function old new delta __inet_hash_nolisten - 282 +282 __inet_hash - 179 +179 tcp_sacktag_write_queue 2255 2254 -1 __inet_lookup_listener 284 274 -10 tcp_v4_syn_recv_sock 755 493 -262 tcp_v4_hash 389 35 -354 inet_hash_connect 1086 599 -487 This version addresses the issue pointed by Eric, that while being inline this function was optimized by gcc in respect to the 'listen_possible' argument. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [INET]: Remove per bucket rwlock in tcp/dccp ehash table.Eric Dumazet2007-11-071-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | As done two years ago on IP route cache table (commit 22c047ccbc68fa8f3fa57f0e8f906479a062c426) , we can avoid using one lock per hash bucket for the huge TCP/DCCP hash tables. On a typical x86_64 platform, this saves about 2MB or 4MB of ram, for litle performance differences. (we hit a different cache line for the rwlock, but then the bucket cache line have a better sharing factor among cpus, since we dirty it less often). For netstat or ss commands that want a full scan of hash table, we perform fewer memory accesses. Using a 'small' table of hashed rwlocks should be more than enough to provide correct SMP concurrency between different buckets, without using too much memory. Sizing of this table depends on num_possible_cpus() and various CONFIG settings. This patch provides some locking abstraction that may ease a future work using a different model for TCP/DCCP table. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [INET]: Justification for local port range robustness.Anton Arapov2007-10-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | There is a justifying patch for Stephen's patches. Stephen's patches disallows using a port range of one single port and brakes the meaning of the 'remaining' variable, in some places it has different meaning. My patch gives back the sense of 'remaining' variable. It should mean how many ports are remaining and nothing else. Also my patch allows using a single port. I sure we must be able to use mentioned port range, this does not restricted by documentation and does not brake current behavior. usefull links: Patches posted by Stephen Hemminger http://marc.info/?l=linux-netdev&m=119206106218187&w=2 http://marc.info/?l=linux-netdev&m=119206109918235&w=2 Andrew Morton's comment http://marc.info/?l=linux-kernel&m=119248225007737&w=2 1. Allows using a port range of one single port. 2. Gives back sense of 'remaining' variable. Signed-off-by: Anton Arapov <aarapov@redhat.com> Acked-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [INET]: local port range robustnessStephen Hemminger2007-10-101-7/+6
| | | | | | | | | | | | | | | Expansion of original idea from Denis V. Lunev <den@openvz.org> Add robustness and locking to the local_port_range sysctl. 1. Enforce that low < high when setting. 2. Use seqlock to ensure atomic update. The locking might seem like overkill, but there are cases where sysadmin might want to change value in the middle of a DoS attack. Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET] IPV4: Fix whitespace errors.YOSHIFUJI Hideaki2007-02-101-52/+52
| | | | | Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: change layout of ehash tableEric Dumazet2007-02-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ehash table layout is currently this one : First half of this table is used by sockets not in TIME_WAIT state Second half of it is used by sockets in TIME_WAIT state. This is non optimal because of for a given hash or socket, the two chain heads are located in separate cache lines. Moreover the locks of the second half are never used. If instead of this halving, we use two list heads in inet_ehash_bucket instead of only one, we probably can avoid one cache miss, and reduce ram usage, particularly if sizeof(rwlock_t) is big (various CONFIG_DEBUG_SPINLOCK, CONFIG_DEBUG_LOCK_ALLOC settings). So we still halves the table but we keep together related chains to speedup lookups and socket state change. In this patch I did not try to align struct inet_ehash_bucket, but a future patch could try to make this structure have a convenient size (a power of two or a multiple of L1_CACHE_SIZE). I guess rwlock will just vanish as soon as RCU is plugged into ehash :) , so maybe we dont need to scratch our heads to align the bucket... Note : In case struct inet_ehash_bucket is not a power of two, we could probably change alloc_large_system_hash() (in case it use __get_free_pages()) to free the unused space. It currently allocates a big zone, but the last quarter of it could be freed. Again, this should be a temporary 'problem'. Patch tested on ipv4 tcp only, but should be OK for IPV6 and DCCP. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [PATCH] slab: remove kmem_cache_tChristoph Lameter2006-12-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace all uses of kmem_cache_t with struct kmem_cache. The patch was generated using the following script: #!/bin/sh # # Replace one string by another in all the kernel sources. # set -e for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do quilt add $file sed -e "1,\$s/$1/$2/g" $file >/tmp/$$ mv /tmp/$$ $file quilt refresh done The script was run like this sh replace kmem_cache_t "struct kmem_cache" Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: remove SLAB_ATOMICChristoph Lameter2006-12-071-1/+1
| | | | | | | | SLAB_ATOMIC is an alias of GFP_ATOMIC Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [IPV4]: annotate inet_lookup() and friendsAl Viro2006-09-281-5/+5
| | | | | | | | | inet_lookup() annotated along with helper functions (__inet_lookup(), __inet_lookup_established(), inet_lookup_established(), inet_lookup_listener(), __inet_lookup_listener() and inet_ehashfn()) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
* [IPV4]: INET_MATCH() annotationsAl Viro2006-09-281-1/+1
| | | | | | | | | | | | | | | INET_MATCH() and friends depend on an interesting set of kludges: * there's a pair of adjacent fields in struct inet_sock - __be16 dport followed by __u16 num. We want to search by pair, so we combine the keys into a single 32bit value and compare with 32bit value read from &...->dport. * on 64bit targets we combine comparisons with pair of adjacent __be32 fields in the same way. Make sure that we don't mix those values with anything else and that pairs we form them from have correct types. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
* [IPV4]: Use network-order dport for all visible inet_lookup_*Herbert Xu2006-09-221-9/+9
| | | | | | | | | | | | | | | | Right now most inet_lookup_* functions take a host-order hnum instead of a network-order dport because that's how it is represented internally. This means that users of these functions have to be careful about using the right byte-order. To add more confusion, inet_lookup takes a network-order dport unlike all other functions. So this patch changes all visible inet_lookup functions to take a dport and move all dport->hnum conversion inside them. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* [IPV4]: Uninline inet_lookup_listenerHerbert Xu2006-09-221-3/+32
| | | | | | | | By modern standards this function is way too big to be inlined. It's even bigger than __inet_lookup_listener :) Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-301-1/+0
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [IPV4]: Possible cleanups.Adrian Bunk2006-04-141-4/+0
| | | | | | | | | | | | | | | | | | | 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>
* [PATCH] s/;;/;/gAlexey Dobriyan2006-03-241-1/+1
| | | | | | Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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