kernel.git/net/sctp/sm_sideeffect.c, branch linux-4.8.y

sctp: sctp should change socket state when shutdown is received

2016-06-11T06:21:23Z

Now sctp doesn't change socket state upon shutdown reception. It changes just the assoc state, even though it's a TCP-style socket. For some cases, if we really need to check sk->sk_state, it's necessary to fix this issue, at least when we use ss or netstat to dump, we can get a more exact information. As an improvement, we will change sk->sk_state when we change asoc->state to SHUTDOWN_RECEIVED, and also do it in sctp_shutdown to keep consistent with sctp_close. Signed-off-by: Xin Long Acked-by: Marcelo R. Leitner Signed-off-by: David S. Miller

sctp: signal sk_data_ready earlier on data chunks reception

2016-05-02T01:06:10Z

Dave Miller pointed out that fb586f25300f ("sctp: delay calls to sk_data_ready() as much as possible") may insert latency specially if the receiving application is running on another CPU and that it would be better if we signalled as early as possible. This patch thus basically inverts the logic on fb586f25300f and signals it as early as possible, similar to what we had before. Fixes: fb586f25300f ("sctp: delay calls to sk_data_ready() as much as possible") Reported-by: Dave Miller Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2016-04-23T22:51:33Z

Conflicts were two cases of simple overlapping changes, nothing serious. In the UDP case, we need to add a hlist_add_tail_rcu() to linux/rculist.h, because we've moved UDP socket handling away from using nulls lists. Signed-off-by: David S. Miller

sctp: delay calls to sk_data_ready() as much as possible

2016-04-14T03:04:44Z

Currently processing of multiple chunks in a single SCTP packet leads to multiple calls to sk_data_ready, causing multiple wake up signals which are costy and doesn't make it wake up any faster. With this patch it will note that the wake up is pending and will do it before leaving the state machine interpreter, latest place possible to do it realiably and cleanly. Note that sk_data_ready events are not dependent on asocs, unlike waking up writers. v2: series re-checked v3: use local vars to cleanup the code, suggested by Jakub Sitnicki Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: avoid refreshing heartbeat timer too often

2016-04-11T02:22:34Z

Currently on high rate SCTP streams the heartbeat timer refresh can consume quite a lot of resources as timer updates are costly and it contains a random factor, which a) is also costly and b) invalidates mod_timer() optimization for not editing a timer to the same value. It may even cause the timer to be slightly advanced, for no good reason. As suggested by David Laight this patch now removes this timer update from hot path by leaving the timer on and re-evaluating upon its expiration if the heartbeat is still needed or not, similarly to what is done for TCP. If it's not needed anymore the timer is re-scheduled to the new timeout, considering the time already elapsed. For this, we now record the last tx timestamp per transport, updated in the same spots as hb timer was restarted on tx. Also split up sctp_transport_reset_timers into sctp_transport_reset_t3_rtx and sctp_transport_reset_hb_timer, so we can re-arm T3 without re-arming the heartbeat one. On loopback with MTU of 65535 and data chunks with 1636, so that we have a considerable amount of chunks without stressing system calls, netperf -t SCTP_STREAM -l 30, perf looked like this before: Samples: 103K of event 'cpu-clock', Event count (approx.): 25833000000 Overhead Command Shared Object Symbol + 6,15% netperf [kernel.vmlinux] [k] copy_user_enhanced_fast_string - 5,43% netperf [kernel.vmlinux] [k] _raw_write_unlock_irqrestore - _raw_write_unlock_irqrestore - 96,54% _raw_spin_unlock_irqrestore - 36,14% mod_timer + 97,24% sctp_transport_reset_timers + 2,76% sctp_do_sm + 33,65% __wake_up_sync_key + 28,77% sctp_ulpq_tail_event + 1,40% del_timer - 1,84% mod_timer + 99,03% sctp_transport_reset_timers + 0,97% sctp_do_sm + 1,50% sctp_ulpq_tail_event And after this patch, now with netperf -l 60: Samples: 230K of event 'cpu-clock', Event count (approx.): 57707250000 Overhead Command Shared Object Symbol + 5,65% netperf [kernel.vmlinux] [k] memcpy_erms + 5,59% netperf [kernel.vmlinux] [k] copy_user_enhanced_fast_string - 5,05% netperf [kernel.vmlinux] [k] _raw_spin_unlock_irqrestore - _raw_spin_unlock_irqrestore + 49,89% __wake_up_sync_key + 45,68% sctp_ulpq_tail_event - 2,85% mod_timer + 76,51% sctp_transport_reset_t3_rtx + 23,49% sctp_do_sm + 1,55% del_timer + 2,50% netperf [sctp] [k] sctp_datamsg_from_user + 2,26% netperf [sctp] [k] sctp_sendmsg Throughput-wise, from 6800mbps without the patch to 7050mbps with it, ~3.7%. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: do not update a_rwnd if we are not issuing a sack

2016-03-20T20:31:11Z

The SACK can be lost pretty much elsewhere, but if its allocation fail, we know we are not sending it, so it is better to revert a_rwnd to its previous value as this may give it a chance to issue a window update later. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: allow sctp_transmit_packet and others to use gfp

2016-03-14T02:29:07Z

Currently sctp_sendmsg() triggers some calls that will allocate memory with GFP_ATOMIC even when not necessary. In the case of sctp_packet_transmit it will allocate a linear skb that will be used to construct the packet and this may cause sends to fail due to ENOMEM more often than anticipated specially with big MTUs. This patch thus allows it to inherit gfp flags from upper calls so that it can use GFP_KERNEL if it was triggered by a sctp_sendmsg call or similar. All others, like retransmits or flushes started from BH, are still allocated using GFP_ATOMIC. In netperf tests this didn't result in any performance drawbacks when memory is not too fragmented and made it trigger ENOMEM way less often. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: remove the dead field of sctp_transport

2016-01-28T23:59:32Z

After we use refcnt to check if transport is alive, the dead can be removed from sctp_transport. The traversal of transport_addr_list in procfs dump is using list_for_each_entry_rcu, no need to check if it has been freed. sctp_generate_t3_rtx_event and sctp_generate_heartbeat_event is protected by sock lock, it's not necessary to check dead, either. also, the timers are cancelled when sctp_transport_free() is called, that it doesn't wait for refcnt to reach 0 to cancel them. Signed-off-by: Xin Long Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2016-01-12T04:55:43Z

Conflicts: drivers/net/bonding/bond_main.c drivers/net/ethernet/mellanox/mlxsw/spectrum.h drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c The bond_main.c and mellanox switch conflicts were cases of overlapping changes. Signed-off-by: David S. Miller

sctp: fix use-after-free in pr_debug statement

2016-01-11T22:13:01Z

Dmitry Vyukov reported a use-after-free in the code expanded by the macro debug_post_sfx, which is caused by the use of the asoc pointer after it was freed within sctp_side_effect() scope. This patch fixes it by allowing sctp_side_effect to clear that asoc pointer when the TCB is freed. As Vlad explained, we also have to cover the SCTP_DISPOSITION_ABORT case because it will trigger DELETE_TCB too on that same loop. Also, there were places issuing SCTP_CMD_INIT_FAILED and ASSOC_FAILED but returning SCTP_DISPOSITION_CONSUME, which would fool the scheme above. Fix it by returning SCTP_DISPOSITION_ABORT instead. The macro is already prepared to handle such NULL pointer. Reported-by: Dmitry Vyukov Signed-off-by: Marcelo Ricardo Leitner Acked-by: Vlad Yasevich Signed-off-by: David S. Miller