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2011-01-10net/sock.h: make some fields private to fix kernel-doc warning(s)Randy Dunlap1-0/+4
Fix new kernel-doc notation warning in sock.h by annotating skc_dontcopy_* as private fields. Warning(include/net/sock.h:163): No description found for parameter 'skc_dontcopy_end[0]' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-17Merge branch 'master' of ↵David S. Miller1-0/+3
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/bnx2x/bnx2x.h drivers/net/wireless/iwlwifi/iwl-1000.c drivers/net/wireless/iwlwifi/iwl-6000.c drivers/net/wireless/iwlwifi/iwl-core.h drivers/vhost/vhost.c
2010-12-17net: fix nulls list corruptions in sk_prot_allocOctavian Purdila1-0/+3
Special care is taken inside sk_port_alloc to avoid overwriting skc_node/skc_nulls_node. We should also avoid overwriting skc_bind_node/skc_portaddr_node. The patch fixes the following crash: BUG: unable to handle kernel paging request at fffffffffffffff0 IP: [<ffffffff812ec6dd>] udp4_lib_lookup2+0xad/0x370 [<ffffffff812ecc22>] __udp4_lib_lookup+0x282/0x360 [<ffffffff812ed63e>] __udp4_lib_rcv+0x31e/0x700 [<ffffffff812bba45>] ? ip_local_deliver_finish+0x65/0x190 [<ffffffff812bbbf8>] ? ip_local_deliver+0x88/0xa0 [<ffffffff812eda35>] udp_rcv+0x15/0x20 [<ffffffff812bba45>] ip_local_deliver_finish+0x65/0x190 [<ffffffff812bbbf8>] ip_local_deliver+0x88/0xa0 [<ffffffff812bb2cd>] ip_rcv_finish+0x32d/0x6f0 [<ffffffff8128c14c>] ? netif_receive_skb+0x99c/0x11c0 [<ffffffff812bb94b>] ip_rcv+0x2bb/0x350 [<ffffffff8128c14c>] netif_receive_skb+0x99c/0x11c0 Signed-off-by: Leonard Crestez <lcrestez@ixiacom.com> Signed-off-by: Octavian Purdila <opurdila@ixiacom.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-10net: optimize INET input path furtherEric Dumazet1-13/+24
Followup of commit b178bb3dfc30 (net: reorder struct sock fields) Optimize INET input path a bit further, by : 1) moving sk_refcnt close to sk_lock. This reduces number of dirtied cache lines by one on 64bit arches (and 64 bytes cache line size). 2) moving inet_daddr & inet_rcv_saddr at the beginning of sk (same cache line than hash / family / bound_dev_if / nulls_node) This reduces number of accessed cache lines in lookups by one, and dont increase size of inet and timewait socks. inet and tw sockets now share same place-holder for these fields. Before patch : offsetof(struct sock, sk_refcnt) = 0x10 offsetof(struct sock, sk_lock) = 0x40 offsetof(struct sock, sk_receive_queue) = 0x60 offsetof(struct inet_sock, inet_daddr) = 0x270 offsetof(struct inet_sock, inet_rcv_saddr) = 0x274 After patch : offsetof(struct sock, sk_refcnt) = 0x44 offsetof(struct sock, sk_lock) = 0x48 offsetof(struct sock, sk_receive_queue) = 0x68 offsetof(struct inet_sock, inet_daddr) = 0x0 offsetof(struct inet_sock, inet_rcv_saddr) = 0x4 compute_score() (udp or tcp) now use a single cache line per ignored item, instead of two. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-09Merge branch 'master' of ↵David S. Miller1-1/+3
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/wireless/ath/ath9k/ar9003_eeprom.c net/llc/af_llc.c
2010-12-06filter: fix sk_filter rcu handlingEric Dumazet1-1/+3
Pavel Emelyanov tried to fix a race between sk_filter_(de|at)tach and sk_clone() in commit 47e958eac280c263397 Problem is we can have several clones sharing a common sk_filter, and these clones might want to sk_filter_attach() their own filters at the same time, and can overwrite old_filter->rcu, corrupting RCU queues. We can not use filter->rcu without being sure no other thread could do the same thing. Switch code to a more conventional ref-counting technique : Do the atomic decrement immediately and queue one rcu call back when last reference is released. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-03net: kill unused macros from head fileShan Wei1-3/+0
These macros have been defined for several years since v2.6.12-rc2(tracing by git), but never be used. So remove them. Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-16net: reorder struct sock fieldsEric Dumazet1-24/+31
Right now, fields in struct sock are not optimally ordered, because each path (RX softirq, TX completion, RX user, TX user) has to touch fields that are contained in many different cache lines. The really critical thing is to shrink number of cache lines that are used at RX softirq time : CPU handling softirqs for a device can receive many frames per second for many sockets. If load is too big, we can drop frames at NIC level. RPS or multiqueue cards can help, but better reduce latency if possible. This patch starts with UDP protocol, then additional patches will try to reduce latencies of other ones as well. At RX softirq time, fields of interest for UDP protocol are : (not counting ones in inet struct for the lookup) Read/Written: sk_refcnt (atomic increment/decrement) sk_rmem_alloc & sk_backlog.len (to check if there is room in queues) sk_receive_queue sk_backlog (if socket locked by user program) sk_rxhash sk_forward_alloc sk_drops Read only: sk_rcvbuf (sk_rcvqueues_full()) sk_filter sk_wq sk_policy[0] sk_flags Additional notes : - sk_backlog has one hole on 64bit arches. We can fill it to save 8 bytes. - sk_backlog is used only if RX sofirq handler finds the socket while locked by user. - sk_rxhash is written only once per flow. - sk_drops is written only if queues are full Final layout : [1] One section grouping all read/write fields, but placing rxhash and sk_backlog at the end of this section. [2] One section grouping all read fields in RX handler (sk_filter, sk_rcv_buf, sk_wq) [3] Section used by other paths I'll post a patch on its own to put sk_refcnt at the end of struct sock_common so that it shares same cache line than section [1] New offsets on 64bit arch : sizeof(struct sock)=0x268 offsetof(struct sock, sk_refcnt) =0x10 offsetof(struct sock, sk_lock) =0x48 offsetof(struct sock, sk_receive_queue)=0x68 offsetof(struct sock, sk_backlog)=0x80 offsetof(struct sock, sk_rmem_alloc)=0x80 offsetof(struct sock, sk_forward_alloc)=0x98 offsetof(struct sock, sk_rxhash)=0x9c offsetof(struct sock, sk_rcvbuf)=0xa4 offsetof(struct sock, sk_drops) =0xa0 offsetof(struct sock, sk_filter)=0xa8 offsetof(struct sock, sk_wq)=0xb0 offsetof(struct sock, sk_policy)=0xd0 offsetof(struct sock, sk_flags) =0xe0 Instead of : sizeof(struct sock)=0x270 offsetof(struct sock, sk_refcnt) =0x10 offsetof(struct sock, sk_lock) =0x50 offsetof(struct sock, sk_receive_queue)=0xc0 offsetof(struct sock, sk_backlog)=0x70 offsetof(struct sock, sk_rmem_alloc)=0xac offsetof(struct sock, sk_forward_alloc)=0x10c offsetof(struct sock, sk_rxhash)=0x128 offsetof(struct sock, sk_rcvbuf)=0x4c offsetof(struct sock, sk_drops) =0x16c offsetof(struct sock, sk_filter)=0x198 offsetof(struct sock, sk_wq)=0x88 offsetof(struct sock, sk_policy)=0x98 offsetof(struct sock, sk_flags) =0x130 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-16udp: use atomic_inc_not_zero_hintEric Dumazet1-1/+1
UDP sockets refcount is usually 2, unless an incoming frame is going to be queued in receive or backlog queue. Using atomic_inc_not_zero_hint() permits to reduce latency, because processor issues less memory transactions. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-10net: avoid limits overflowEric Dumazet1-2/+2
Robin Holt tried to boot a 16TB machine and found some limits were reached : sysctl_tcp_mem[2], sysctl_udp_mem[2] We can switch infrastructure to use long "instead" of "int", now atomic_long_t primitives are available for free. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Reported-by: Robin Holt <holt@sgi.com> Reviewed-by: Robin Holt <holt@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-26net: add __rcu annotation to sk_filterEric Dumazet1-1/+1
Add __rcu annotation to : (struct sock)->sk_filter And use appropriate rcu primitives to reduce sparse warnings if CONFIG_SPARSE_RCU_POINTER=y Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-27net: update SOCK_MIN_RCVBUFEric Dumazet1-1/+5
SOCK_MIN_RCVBUF current value is 256 bytes It doesnt permit to receive the smallest possible frame, considering socket sk_rmem_alloc/sk_rcvbuf account skb truesizes. On 64bit arches, sizeof(struct sk_buff) is 240 bytes. Add the typical 64 bytes of headroom, and we go over the limit. With old kernels and 32bit arches, we were under the limit, if netdriver was doing copybreak. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-10Merge branch 'master' of ↵David S. Miller1-0/+1
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: net/mac80211/main.c
2010-09-09udp: add rehash on connect()Eric Dumazet1-0/+1
commit 30fff923 introduced in linux-2.6.33 (udp: bind() optimisation) added a secondary hash on UDP, hashed on (local addr, local port). Problem is that following sequence : fd = socket(...) connect(fd, &remote, ...) not only selects remote end point (address and port), but also sets local address, while UDP stack stored in secondary hash table the socket while its local address was INADDR_ANY (or ipv6 equivalent) Sequence is : - autobind() : choose a random local port, insert socket in hash tables [while local address is INADDR_ANY] - connect() : set remote address and port, change local address to IP given by a route lookup. When an incoming UDP frame comes, if more than 10 sockets are found in primary hash table, we switch to secondary table, and fail to find socket because its local address changed. One solution to this problem is to rehash datagram socket if needed. We add a new rehash(struct socket *) method in "struct proto", and implement this method for UDP v4 & v6, using a common helper. This rehashing only takes care of secondary hash table, since primary hash (based on local port only) is not changed. Reported-by: Krzysztof Piotr Oledzki <ole@ans.pl> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Tested-by: Krzysztof Piotr Oledzki <ole@ans.pl> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-19net: simplify flags for tx timestampingOliver Hartkopp1-6/+2
This patch removes the abstraction introduced by the union skb_shared_tx in the shared skb data. The access of the different union elements at several places led to some confusion about accessing the shared tx_flags e.g. in skb_orphan_try(). http://marc.info/?l=linux-netdev&m=128084897415886&w=2 Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-10net/sock.h: add missing kernel-doc notationRandy Dunlap1-1/+3
Add missing kernel-doc notation to struct sock: Warning(include/net/sock.h:324): No description found for parameter 'sk_peer_pid' Warning(include/net/sock.h:324): No description found for parameter 'sk_peer_cred' Warning(include/net/sock.h:324): No description found for parameter 'sk_classid' Warning(include/net/sock.h:324): Excess struct/union/enum/typedef member 'sk_peercred' description in 'sock' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-21Merge branch 'master' of ↵David S. Miller1-6/+1
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/vhost/net.c net/bridge/br_device.c Fix merge conflict in drivers/vhost/net.c with guidance from Stephen Rothwell. Revert the effects of net-2.6 commit 573201f36fd9c7c6d5218cdcd9948cee700b277d since net-next-2.6 has fixes that make bridge netpoll work properly thus we don't need it disabled. Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-15net: fix problem in reading sock TX queueTom Herbert1-6/+1
Fix problem in reading the tx_queue recorded in a socket. In dev_pick_tx, the TX queue is read by doing a check with sk_tx_queue_recorded on the socket, followed by a sk_tx_queue_get. The problem is that there is not mutual exclusion across these calls in the socket so it it is possible that the queue in the sock can be invalidated after sk_tx_queue_recorded is called so that sk_tx_queue get returns -1, which sets 65535 in queue_index and thus dev_pick_tx returns 65536 which is a bogus queue and can cause crash in dev_queue_xmit. We fix this by only calling sk_tx_queue_get which does the proper checks. The interface is that sk_tx_queue_get returns the TX queue if the sock argument is non-NULL and TX queue is recorded, else it returns -1. sk_tx_queue_recorded is no longer used so it can be completely removed. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-13inet, inet6: make tcp_sendmsg() and tcp_sendpage() through inet_sendmsg() ↵Changli Gao1-0/+1
and inet_sendpage() a new boolean flag no_autobind is added to structure proto to avoid the autobind calls when the protocol is TCP. Then sock_rps_record_flow() is called int the TCP's sendmsg() and sendpage() pathes. Signed-off-by: Changli Gao <xiaosuo@gmail.com> ---- include/net/inet_common.h | 4 ++++ include/net/sock.h | 1 + include/net/tcp.h | 8 ++++---- net/ipv4/af_inet.c | 15 +++++++++------ net/ipv4/tcp.c | 11 +++++------ net/ipv4/tcp_ipv4.c | 3 +++ net/ipv6/af_inet6.c | 8 ++++---- net/ipv6/tcp_ipv6.c | 3 +++ 8 files changed, 33 insertions(+), 20 deletions(-) Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-17af_unix: Allow SO_PEERCRED to work across namespaces.Eric W. Biederman1-1/+2
Use struct pid and struct cred to store the peer credentials on struct sock. This gives enough information to convert the peer credential information to a value relative to whatever namespace the socket is in at the time. This removes nasty surprises when using SO_PEERCRED on socket connetions where the processes on either side are in different pid and user namespaces. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Daniel Lezcano <daniel.lezcano@free.fr> Acked-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-07Merge branch 'master' of ↵David S. Miller1-14/+1
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/sfc/net_driver.h drivers/net/sfc/siena.c
2010-06-02net: CONFIG_NET_NS reductionEric Dumazet1-8/+2
Use read_pnet() and write_pnet() to reduce number of ifdef CONFIG_NET_NS Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-01net: sock_queue_err_skb() dont mess with sk_forward_allocEric Dumazet1-14/+1
Correct sk_forward_alloc handling for error_queue would need to use a backlog of frames that softirq handler could not deliver because socket is owned by user thread. Or extend backlog processing to be able to process normal and error packets. Another possibility is to not use mem charge for error queue, this is what I implemented in this patch. Note: this reverts commit 29030374 (net: fix sk_forward_alloc corruptions), since we dont need to lock socket anymore. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-27net: fix lock_sock_bh/unlock_sock_bhEric Dumazet1-6/+14
This new sock lock primitive was introduced to speedup some user context socket manipulation. But it is unsafe to protect two threads, one using regular lock_sock/release_sock, one using lock_sock_bh/unlock_sock_bh This patch changes lock_sock_bh to be careful against 'owned' state. If owned is found to be set, we must take the slow path. lock_sock_bh() now returns a boolean to say if the slow path was taken, and this boolean is used at unlock_sock_bh time to call the appropriate unlock function. After this change, BH are either disabled or enabled during the lock_sock_bh/unlock_sock_bh protected section. This might be misleading, so we rename these functions to lock_sock_fast()/unlock_sock_fast(). Reported-by: Anton Blanchard <anton@samba.org> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-25sock.h: fix kernel-doc warningRandy Dunlap1-1/+1
Fix sock.h kernel-doc warning: Warning(include/net/sock.h:1438): No description found for parameter 'wq' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-24cls_cgroup: Store classid in struct sockHerbert Xu1-1/+9
Up until now cls_cgroup has relied on fetching the classid out of the current executing thread. This runs into trouble when a packet processing is delayed in which case it may execute out of another thread's context. Furthermore, even when a packet is not delayed we may fail to classify it if soft IRQs have been disabled, because this scenario is indistinguishable from one where a packet unrelated to the current thread is processed by a real soft IRQ. In fact, the current semantics is inherently broken, as a single skb may be constructed out of the writes of two different tasks. A different manifestation of this problem is when the TCP stack transmits in response of an incoming ACK. This is currently unclassified. As we already have a concept of packet ownership for accounting purposes in the skb->sk pointer, this is a natural place to store the classid in a persistent manner. This patch adds the cls_cgroup classid in struct sock, filling up an existing hole on 64-bit :) The value is set at socket creation time. So all sockets created via socket(2) automatically gains the ID of the thread creating it. Whenever another process touches the socket by either reading or writing to it, we will change the socket classid to that of the process if it has a valid (non-zero) classid. For sockets created on inbound connections through accept(2), we inherit the classid of the original listening socket through sk_clone, possibly preceding the actual accept(2) call. In order to minimise risks, I have not made this the authoritative classid. For now it is only used as a backup when we execute with soft IRQs disabled. Once we're completely happy with its semantics we can use it as the sole classid. Footnote: I have rearranged the error path on cls_group module creation. If we didn't do this, then there is a window where someone could create a tc rule using cls_group before the cgroup subsystem has been registered. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-18net: add a noref bit on skb dstEric Dumazet1-5/+8
Use low order bit of skb->_skb_dst to tell dst is not refcounted. Change _skb_dst to _skb_refdst to make sure all uses are catched. skb_dst() returns the dst, regardless of noref bit set or not, but with a lockdep check to make sure a noref dst is not given if current user is not rcu protected. New skb_dst_set_noref() helper to set an notrefcounted dst on a skb. (with lockdep check) skb_dst_drop() drops a reference only if skb dst was refcounted. skb_dst_force() helper is used to force a refcount on dst, when skb is queued and not anymore RCU protected. Use skb_dst_force() in __sk_add_backlog(), __dev_xmit_skb() if !IFF_XMIT_DST_RELEASE or skb enqueued on qdisc queue, in sock_queue_rcv_skb(), in __nf_queue(). Use skb_dst_force() in dev_requeue_skb(). Note: dst_use_noref() still dirties dst, we might transform it later to do one dirtying per jiffies. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-16net: Introduce sk_route_nocapsEric Dumazet1-0/+8
TCP-MD5 sessions have intermittent failures, when route cache is invalidated. ip_queue_xmit() has to find a new route, calls sk_setup_caps(sk, &rt->u.dst), destroying the sk->sk_route_caps &= ~NETIF_F_GSO_MASK that MD5 desperately try to make all over its way (from tcp_transmit_skb() for example) So we send few bad packets, and everything is fine when tcp_transmit_skb() is called again for this socket. Since ip_queue_xmit() is at a lower level than TCP-MD5, I chose to use a socket field, sk_route_nocaps, containing bits to mask on sk_route_caps. Reported-by: Bhaskar Dutta <bhaskie@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-03Merge branch 'master' of ↵David S. Miller1-1/+1
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
2010-05-03net: fix compile error due to double return type in SOCK_DEBUGJan Engelhardt1-1/+1
Fix this one: include/net/sock.h: error: two or more data types in declaration specifiers Signed-off-by: Jan Engelhardt <jengelh@medozas.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-02net: sock_def_readable() and friends RCU conversionEric Dumazet1-19/+19
sk_callback_lock rwlock actually protects sk->sk_sleep pointer, so we need two atomic operations (and associated dirtying) per incoming packet. RCU conversion is pretty much needed : 1) Add a new structure, called "struct socket_wq" to hold all fields that will need rcu_read_lock() protection (currently: a wait_queue_head_t and a struct fasync_struct pointer). [Future patch will add a list anchor for wakeup coalescing] 2) Attach one of such structure to each "struct socket" created in sock_alloc_inode(). 3) Respect RCU grace period when freeing a "struct socket_wq" 4) Change sk_sleep pointer in "struct sock" by sk_wq, pointer to "struct socket_wq" 5) Change sk_sleep() function to use new sk->sk_wq instead of sk->sk_sleep 6) Change sk_has_sleeper() to wq_has_sleeper() that must be used inside a rcu_read_lock() section. 7) Change all sk_has_sleeper() callers to : - Use rcu_read_lock() instead of read_lock(&sk->sk_callback_lock) - Use wq_has_sleeper() to eventually wakeup tasks. - Use rcu_read_unlock() instead of read_unlock(&sk->sk_callback_lock) 8) sock_wake_async() is modified to use rcu protection as well. 9) Exceptions : macvtap, drivers/net/tun.c, af_unix use integrated "struct socket_wq" instead of dynamically allocated ones. They dont need rcu freeing. Some cleanups or followups are probably needed, (possible sk_callback_lock conversion to a spinlock for example...). Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-01net: speedup sock_recv_ts_and_drops()Eric Dumazet1-1/+18
sock_recv_ts_and_drops() is fat and slow (~ 4% of cpu time on some profiles) We can test all socket flags at once to make fast path fast again. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-29net: speedup udp receive pathEric Dumazet1-0/+10
Since commit 95766fff ([UDP]: Add memory accounting.), each received packet needs one extra sock_lock()/sock_release() pair. This added latency because of possible backlog handling. Then later, ticket spinlocks added yet another latency source in case of DDOS. This patch introduces lock_sock_bh() and unlock_sock_bh() synchronization primitives, avoiding one atomic operation and backlog processing. skb_free_datagram_locked() uses them instead of full blown lock_sock()/release_sock(). skb is orphaned inside locked section for proper socket memory reclaim, and finally freed outside of it. UDP receive path now take the socket spinlock only once. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-28net: sk_add_backlog() take rmem_alloc into accountEric Dumazet1-2/+11
Current socket backlog limit is not enough to really stop DDOS attacks, because user thread spend many time to process a full backlog each round, and user might crazy spin on socket lock. We should add backlog size and receive_queue size (aka rmem_alloc) to pace writers, and let user run without being slow down too much. Introduce a sk_rcvqueues_full() helper, to avoid taking socket lock in stress situations. Under huge stress from a multiqueue/RPS enabled NIC, a single flow udp receiver can now process ~200.000 pps (instead of ~100 pps before the patch) on a 8 core machine. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-28net: Make RFS socket operations not be inet specific.David S. Miller1-0/+38
Idea from Eric Dumazet. As for placement inside of struct sock, I tried to choose a place that otherwise has a 32-bit hole on 64-bit systems. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
2010-04-27net: fix a lockdep rcu warning in __sk_dst_set()Eric Dumazet1-2/+5
__sk_dst_set() might be called while no state can be integrated in a rcu_dereference_check() condition. So use rcu_dereference_raw() to shutup lockdep warnings (if CONFIG_PROVE_RCU is set) Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-23dst: rcu check refinementEric Dumazet1-1/+2
__sk_dst_get() might be called from softirq, with socket lock held. [ 159.026180] include/net/sock.h:1200 invoked rcu_dereference_check() without protection! [ 159.026261] [ 159.026261] other info that might help us debug this: [ 159.026263] [ 159.026425] [ 159.026426] rcu_scheduler_active = 1, debug_locks = 0 [ 159.026552] 2 locks held by swapper/0: [ 159.026609] #0: (&icsk->icsk_retransmit_timer){+.-...}, at: [<ffffffff8104fc15>] run_timer_softirq+0x105/0x350 [ 159.026839] #1: (slock-AF_INET){+.-...}, at: [<ffffffff81392b8f>] tcp_write_timer+0x2f/0x1e0 [ 159.027063] [ 159.027064] stack backtrace: [ 159.027172] Pid: 0, comm: swapper Not tainted 2.6.34-rc5-03707-gde498c8-dirty #36 [ 159.027252] Call Trace: [ 159.027306] <IRQ> [<ffffffff810718ef>] lockdep_rcu_dereference +0xaf/0xc0 [ 159.027411] [<ffffffff8138e4f7>] tcp_current_mss+0xa7/0xb0 [ 159.027537] [<ffffffff8138fa49>] tcp_write_wakeup+0x89/0x190 [ 159.027600] [<ffffffff81391936>] tcp_send_probe0+0x16/0x100 [ 159.027726] [<ffffffff81392cd9>] tcp_write_timer+0x179/0x1e0 [ 159.027790] [<ffffffff8104fca1>] run_timer_softirq+0x191/0x350 [ 159.027980] [<ffffffff810477ed>] __do_softirq+0xcd/0x200 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-21net: sk_sleep() helperEric Dumazet1-3/+7
Define a new function to return the waitqueue of a "struct sock". static inline wait_queue_head_t *sk_sleep(struct sock *sk) { return sk->sk_sleep; } Change all read occurrences of sk_sleep by a call to this function. Needed for a future RCU conversion. sk_sleep wont be a field directly available. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-13net: sk_dst_cache RCUificationEric Dumazet1-17/+30
With latest CONFIG_PROVE_RCU stuff, I felt more comfortable to make this work. sk->sk_dst_cache is currently protected by a rwlock (sk_dst_lock) This rwlock is readlocked for a very small amount of time, and dst entries are already freed after RCU grace period. This calls for RCU again :) This patch converts sk_dst_lock to a spinlock, and use RCU for readers. __sk_dst_get() is supposed to be called with rcu_read_lock() or if socket locked by user, so use appropriate rcu_dereference_check() condition (rcu_read_lock_held() || sock_owned_by_user(sk)) This patch avoids two atomic ops per tx packet on UDP connected sockets, for example, and permits sk_dst_lock to be much less dirtied. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> 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 Heo1-0/+1
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>
2010-03-08net: add __must_check to sk_add_backlogZhu Yi1-1/+1
Add the "__must_check" tag to sk_add_backlog() so that any failure to check and drop packets will be warned about. Signed-off-by: Zhu Yi <yi.zhu@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-06net: backlog functions renameZhu Yi1-3/+3
sk_add_backlog -> __sk_add_backlog sk_add_backlog_limited -> sk_add_backlog Signed-off-by: Zhu Yi <yi.zhu@intel.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-06net: add limit for socket backlogZhu Yi1-1/+14
We got system OOM while running some UDP netperf testing on the loopback device. The case is multiple senders sent stream UDP packets to a single receiver via loopback on local host. Of course, the receiver is not able to handle all the packets in time. But we surprisingly found that these packets were not discarded due to the receiver's sk->sk_rcvbuf limit. Instead, they are kept queuing to sk->sk_backlog and finally ate up all the memory. We believe this is a secure hole that a none privileged user can crash the system. The root cause for this problem is, when the receiver is doing __release_sock() (i.e. after userspace recv, kernel udp_recvmsg -> skb_free_datagram_locked -> release_sock), it moves skbs from backlog to sk_receive_queue with the softirq enabled. In the above case, multiple busy senders will almost make it an endless loop. The skbs in the backlog end up eat all the system memory. The issue is not only for UDP. Any protocols using socket backlog is potentially affected. The patch adds limit for socket backlog so that the backlog size cannot be expanded endlessly. Reported-by: Alex Shi <alex.shi@intel.com> Cc: David Miller <davem@davemloft.net> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru Cc: "Pekka Savola (ipv6)" <pekkas@netcore.fi> Cc: Patrick McHardy <kaber@trash.net> Cc: Vlad Yasevich <vladislav.yasevich@hp.com> Cc: Sridhar Samudrala <sri@us.ibm.com> Cc: Jon Maloy <jon.maloy@ericsson.com> Cc: Allan Stephens <allan.stephens@windriver.com> Cc: Andrew Hendry <andrew.hendry@gmail.com> Signed-off-by: Zhu Yi <yi.zhu@intel.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-23packet: convert socket list to RCU (v3)stephen hemminger1-0/+10
Convert AF_PACKET to use RCU, eliminating one more reader/writer lock. There is no need for a real sk_del_node_init_rcu(), because sk_del_node_init is doing the equivalent thing to hlst_del_init_rcu already; but added some comments to try and make that obvious. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-15net: Fix first line of kernel-doc for a few functionsBen Hutchings1-1/+1
The function name must be followed by a space, hypen, space, and a short description. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-10net: add a wrapper sk_entry()Li Zefan1-0/+5
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-09udp: secondary hash on (local port, local address)Eric Dumazet1-2/+6
Extends udp_table to contain a secondary hash table. socket anchor for this second hash is free, because UDP doesnt use skc_bind_node : We define an union to hold both skc_bind_node & a new hlist_nulls_node udp_portaddr_node udp_lib_get_port() inserts sockets into second hash chain (additional cost of one atomic op) udp_lib_unhash() deletes socket from second hash chain (additional cost of one atomic op) Note : No spinlock lockdep annotation is needed, because lock for the secondary hash chain is always get after lock for primary hash chain. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-09udp: split sk_hash into two u16 hashesEric Dumazet1-1/+5
Union sk_hash with two u16 hashes for udp (no extra memory taken) One 16 bits hash on (local port) value (the previous udp 'hash') One 16 bits hash on (local address, local port) values, initialized but not yet used. This second hash is using jenkin hash for better distribution. Because the 'port' is xored later, a partial hash is performed on local address + net_hash_mix(net) Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-21net: Introduce sk_tx_queue_mappingKrishna Kumar1-0/+26
Introduce sk_tx_queue_mapping; and functions that set, test and get this value. Reset sk_tx_queue_mapping to -1 whenever the dst cache is set/reset, and in socket alloc. Setting txq to -1 and using valid txq=<0 to n-1> allows the tx path to use the value of sk_tx_queue_mapping directly instead of subtracting 1 on every tx. Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-13Merge branch 'master' of ↵David S. Miller1-5/+5
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6