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2017-12-12tcp: smoother receiver autotuningEric Dumazet1-14/+5
Back in linux-3.13 (commit b0983d3c9b13 ("tcp: fix dynamic right sizing")) I addressed the pressing issues we had with receiver autotuning. But DRS suffers from extra latencies caused by rcv_rtt_est.rtt_us drifts. One common problem happens during slow start, since the apparent RTT measured by the receiver can be inflated by ~50%, at the end of one packet train. Also, a single drop can delay read() calls by one RTT, meaning tcp_rcv_space_adjust() can be called one RTT too late. By replacing the tri-modal heuristic with a continuous function, we can offset the effects of not growing 'at the optimal time'. The curve of the function matches prior behavior if the space increased by 25% and 50% exactly. Cost of added multiply/divide is small, considering a TCP flow typically would run this part of the code few times in its life. I tested this patch with 100 ms RTT / 1% loss link, 100 runs of (netperf -l 5), and got an average throughput of 4600 Mbit instead of 1700 Mbit. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Wei Wang <weiwan@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-12tcp: avoid integer overflows in tcp_rcv_space_adjust()Eric Dumazet1-5/+7
When using large tcp_rmem[2] values (I did tests with 500 MB), I noticed overflows while computing rcvwin. Lets fix this before the following patch. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Wei Wang <weiwan@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-12tcp: do not overshoot window_clamp in tcp_rcv_space_adjust()Eric Dumazet1-1/+1
While rcvbuf is properly clamped by tcp_rmem[2], rcvwin is left to a potentially too big value. It has no serious effect, since : 1) tcp_grow_window() has very strict checks. 2) window_clamp can be mangled by user space to any value anyway. tcp_init_buffer_space() and companions use tcp_full_space(), we use tcp_win_from_space() to avoid reloading sk->sk_rcvbuf Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Wei Wang <weiwan@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11sctp: add support for the process of unordered idataXin Long3-27/+378
Unordered idata process is more complicated than unordered data: - It has to add mid into sctp_stream_out to save the next mid value, which is separated from ordered idata's. - To support pd for unordered idata, another mid and pd_mode need to be added to save the message id and pd state in sctp_stream_in. - To make unordered idata reasm easier, it adds a new event queue to save frags for idata. The patch mostly adds the samilar reasm functions for unordered idata as ordered idata's, and also adjusts some other codes on assign_mid, abort_pd and ulpevent_data for idata. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11sctp: implement abort_pd for sctp_stream_interleaveXin Long4-5/+107
abort_pd is added as a member of sctp_stream_interleave, used to abort partial delivery for data or idata, called in sctp_cmd_assoc_failed. Since stream interleave allows to do partial delivery for each stream at the same time, sctp_intl_abort_pd for idata would be very different from the old function sctp_ulpq_abort_pd for data. Note that sctp_ulpevent_make_pdapi will support per stream in this patch by adding pdapi_stream and pdapi_seq in sctp_pdapi_event, as described in section 6.1.7 of RFC6458. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11sctp: implement start_pd for sctp_stream_interleaveXin Long2-1/+3
start_pd is added as a member of sctp_stream_interleave, used to do partial_delivery for data or idata when datalen >= asoc->rwnd in sctp_eat_data. The codes have been done in last patches, but they need to be extracted into start_pd, so that it could be used for SCTP_CMD_PART_DELIVER cmd as well. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11sctp: implement renege_events for sctp_stream_interleaveXin Long3-4/+114
renege_events is added as a member of sctp_stream_interleave, used to renege some old data or idata in reasm or lobby queue properly to free some memory for the new data when there's memory stress. It defines sctp_renege_events for idata, and leaves sctp_ulpq_renege as it is for data. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11sctp: implement enqueue_event for sctp_stream_interleaveXin Long5-7/+10
enqueue_event is added as a member of sctp_stream_interleave, used to enqueue either data, idata or notification events into user socket rx queue. It replaces sctp_ulpq_tail_event used in the other places with enqueue_event. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11sctp: implement ulpevent_data for sctp_stream_interleaveXin Long4-8/+429
ulpevent_data is added as a member of sctp_stream_interleave, used to do the most process in ulpq, including to convert data or idata chunk to event, reasm them in reasm queue and put them in lobby queue in right order, and deliver them up to user sk rx queue. This procedure is described in section 2.2.3 of RFC8260. It adds most functions for idata here to do the similar process as the old functions for data. But since the details are very different between them, the old functions can not be reused for idata. event->ssn and event->ppid settings are moved to ulpevent_data from sctp_ulpevent_make_rcvmsg, so that sctp_ulpevent_make_rcvmsg could work for both data and idata. Note that mid is added in sctp_ulpevent for idata, __packed has to be used for defining sctp_ulpevent, or it would exceeds the skb cb that saves a sctp_ulpevent variable for ulp layer process. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11sctp: implement validate_data for sctp_stream_interleaveXin Long3-13/+50
validate_data is added as a member of sctp_stream_interleave, used to validate ssn/chunk type for data or mid (message id)/chunk type for idata, called in sctp_eat_data. If this check fails, an abort packet will be sent, as said in section 2.2.3 of RFC8260. It also adds the process for idata in rx path. As Marcelo pointed out, there's no need to add event table for idata, but just share chunk_event_table with data's. It would drop data chunk for idata and drop idata chunk for data by calling validate_data in sctp_eat_data. As last patch did, it also replaces sizeof(struct sctp_data_chunk) with sctp_datachk_len for rx path. After this patch, the idata can be accepted and delivered to ulp layer. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11sctp: implement assign_number for sctp_stream_interleaveXin Long4-6/+57
assign_number is added as a member of sctp_stream_interleave, used to assign ssn for data or mid (message id) for idata, called in sctp_packet_append_data. sctp_chunk_assign_ssn is left as it is, and sctp_chunk_assign_mid is added for sctp_stream_interleave_1. This procedure is described in section 2.2.2 of RFC8260. All sizeof(struct sctp_data_chunk) in tx path is replaced with sctp_datachk_len, to make it right for idata as well. And also adjust sctp_chunk_is_data for SCTP_CID_I_DATA. After this patch, idata can be built and sent in tx path. Note that if sp strm_interleave is set, it has to wait_connect in sctp_sendmsg, as asoc intl_enable need to be known after 4 shake- hands, to decide if it should use data or idata later. data and idata can't be mixed to send in one asoc. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11sctp: implement make_datafrag for sctp_stream_interleaveXin Long5-18/+91
To avoid hundreds of checks for the different process on I-DATA chunk, struct sctp_stream_interleave is defined as a group of functions used to replace the codes in some place where it needs to do different job according to if the asoc intl_enabled is set. With these ops, it only needs to initialize asoc->stream.si with sctp_stream_interleave_0 for normal data if asoc intl_enable is 0, or sctp_stream_interleave_1 for idata if asoc intl_enable is set in sctp_stream_init. After that, the members in asoc->stream.si can be used directly in some special places without checking asoc intl_enable. make_datafrag is the first member for sctp_stream_interleave, it's used to make data or idata frags, called in sctp_datamsg_from_user. The old function sctp_make_datafrag_empty needs to be adjust some to fit in this ops. Note that as idata and data chunks have different length, it also defines data_chunk_len for sctp_stream_interleave to describe the chunk size. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11sctp: add basic structures and make chunk function for idataXin Long1-0/+6
sctp_idatahdr and sctp_idata_chunk are used to define and parse I-DATA chunk format, and sctp_make_idata is a function to build the chunk. The I-DATA Chunk Format is defined in section 2.1 of RFC8260. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11sctp: add asoc intl_enable negotiation during 4 shakehandsXin Long1-2/+16
asoc intl_enable will be set when local sp strm_interleave is set and there's I-DATA chunk in init and init_ack extensions, as said in section 2.2.1 of RFC8260. asoc intl_enable indicates all data will be sent as I-DATA chunks. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11sctp: add stream interleave enable members and sockoptXin Long1-1/+87
This patch adds intl_enable in asoc and netns, and strm_interleave in sctp_sock to indicate if stream interleave is enabled and supported. netns intl_enable would be set via procfs, but that is not added yet until all stream interleave codes are completely implemented; asoc intl_enable will be set when doing 4-shakehands. sp strm_interleave can be set by sockopt SCTP_INTERLEAVING_SUPPORTED which is also added in this patch. This socket option is defined in section 4.3.1 of RFC8260. Note that strm_interleave can only be set by sockopt when both netns intl_enable and sp frag_interleave are set. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11netlink: convert netlink tap spinlock to mutexCong Wang1-6/+6
Both netlink_add_tap() and netlink_remove_tap() are called in process context, no need to bother spinlock. Note, in fact, currently we always hold RTNL when calling these two functions, so we don't need any other lock at all, but keeping this lock doesn't harm anything. Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11netlink: make netlink tap per netnsCong Wang1-17/+49
nlmon device is not supposed to capture netlink events from other netns, so instead of filtering events, we can simply make netlink tap itself per netns. Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Kevin Cernekee <cernekee@chromium.org> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11rhashtable: Change rhashtable_walk_start to return voidTom Herbert9-70/+26
Most callers of rhashtable_walk_start don't care about a resize event which is indicated by a return value of -EAGAIN. So calls to rhashtable_walk_start are wrapped wih code to ignore -EAGAIN. Something like this is common: ret = rhashtable_walk_start(rhiter); if (ret && ret != -EAGAIN) goto out; Since zero and -EAGAIN are the only possible return values from the function this check is pointless. The condition never evaluates to true. This patch changes rhashtable_walk_start to return void. This simplifies code for the callers that ignore -EAGAIN. For the few cases where the caller cares about the resize event, particularly where the table can be walked in mulitple parts for netlink or seq file dump, the function rhashtable_walk_start_check has been added that returns -EAGAIN on a resize event. Signed-off-by: Tom Herbert <tom@quantonium.net> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11rtnetlink: fix typo in GSO max segmentsStephen Hemminger1-1/+1
Fixes: 46e6b992c250 ("rtnetlink: allow GSO maximums to be set on device creation") Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller21-143/+136
Conflict was two parallel additions of include files to sch_generic.c, no biggie. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08rtnetlink: allow GSO maximums to be set on device creationStephen Hemminger1-0/+34
Netlink device already allows changing GSO sizes with ip set command. The part that is missing is allowing overriding GSO settings on device creation. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08tcp: evaluate packet losses upon RTT changeYuchung Cheng1-11/+8
RACK skips an ACK unless it advances the most recently delivered TX timestamp (rack.mstamp). Since RACK also uses the most recent RTT to decide if a packet is lost, RACK should still run the loss detection whenever the most recent RTT changes. For example, an ACK that does not advance the timestamp but triggers the cwnd undo due to reordering, would then use the most recent (higher) RTT measurement to detect further losses. Signed-off-by: Yuchung Cheng <ycheng@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Priyaranjan Jha <priyarjha@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08tcp: fix off-by-one bug in RACKYuchung Cheng1-3/+3
RACK should mark a packet lost when remaining wait time is zero. Signed-off-by: Yuchung Cheng <ycheng@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Priyaranjan Jha <priyarjha@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08tcp: always evaluate losses in RACK upon undoYuchung Cheng1-0/+1
When sender detects spurious retransmission, all packets marked lost are remarked to be in-flight. However some may be considered lost based on its timestamps in RACK. This patch forces RACK to re-evaluate, which may be skipped previously if the ACK does not advance RACK timestamp. Signed-off-by: Yuchung Cheng <ycheng@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Priyaranjan Jha <priyarjha@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08tcp: correctly test congestion state in RACKYuchung Cheng1-1/+2
RACK does not test the loss recovery state correctly to compute the reordering window. It assumes if lost_out is zero then TCP is not in loss recovery. But it can be zero during recovery before calling tcp_rack_detect_loss(): when an ACK acknowledges all packets marked lost before receiving this ACK, but has not yet to discover new ones by tcp_rack_detect_loss(). The fix is to simply test the congestion state directly. Signed-off-by: Yuchung Cheng <ycheng@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Priyaranjan Jha <priyarjha@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08net: sched: fix use-after-free in tcf_block_put_extJiri Pirko1-6/+7
Since the block is freed with last chain being put, once we reach the end of iteration of list_for_each_entry_safe, the block may be already freed. I'm hitting this only by creating and deleting clsact: [ 202.171952] ================================================================== [ 202.180182] BUG: KASAN: use-after-free in tcf_block_put_ext+0x240/0x390 [ 202.187590] Read of size 8 at addr ffff880225539a80 by task tc/796 [ 202.194508] [ 202.196185] CPU: 0 PID: 796 Comm: tc Not tainted 4.15.0-rc2jiri+ #5 [ 202.203200] Hardware name: Mellanox Technologies Ltd. "MSN2100-CB2F"/"SA001017", BIOS 5.6.5 06/07/2016 [ 202.213613] Call Trace: [ 202.216369] dump_stack+0xda/0x169 [ 202.220192] ? dma_virt_map_sg+0x147/0x147 [ 202.224790] ? show_regs_print_info+0x54/0x54 [ 202.229691] ? tcf_chain_destroy+0x1dc/0x250 [ 202.234494] print_address_description+0x83/0x3d0 [ 202.239781] ? tcf_block_put_ext+0x240/0x390 [ 202.244575] kasan_report+0x1ba/0x460 [ 202.248707] ? tcf_block_put_ext+0x240/0x390 [ 202.253518] tcf_block_put_ext+0x240/0x390 [ 202.258117] ? tcf_chain_flush+0x290/0x290 [ 202.262708] ? qdisc_hash_del+0x82/0x1a0 [ 202.267111] ? qdisc_hash_add+0x50/0x50 [ 202.271411] ? __lock_is_held+0x5f/0x1a0 [ 202.275843] clsact_destroy+0x3d/0x80 [sch_ingress] [ 202.281323] qdisc_destroy+0xcb/0x240 [ 202.285445] qdisc_graft+0x216/0x7b0 [ 202.289497] tc_get_qdisc+0x260/0x560 Fix this by holding the block also by chain 0 and put chain 0 explicitly, out of the list_for_each_entry_safe loop at the very end of tcf_block_put_ext. Fixes: efbf78973978 ("net_sched: get rid of rcu_barrier() in tcf_block_put_ext()") Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08net: sched: pfifo_fast use skb_arrayJohn Fastabend2-53/+92
This converts the pfifo_fast qdisc to use the skb_array data structure and set the lockless qdisc bit. pfifo_fast is the first qdisc to support the lockless bit that can be a child of a qdisc requiring locking. So we add logic to clear the lock bit on initialization in these cases when the qdisc graft operation occurs. This also removes the logic used to pick the next band to dequeue from and instead just checks a per priority array for packets from top priority to lowest. This might need to be a bit more clever but seems to work for now. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08net: sched: add support for TCQ_F_NOLOCK subqueues to sch_mqprioJohn Fastabend2-35/+69
The sch_mqprio qdisc creates a sub-qdisc per tx queue which are then called independently for enqueue and dequeue operations. However statistics are aggregated and pushed up to the "master" qdisc. This patch adds support for any of the sub-qdiscs to be per cpu statistic qdiscs. To handle this case add a check when calculating stats and aggregate the per cpu stats if needed. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08net: sched: add support for TCQ_F_NOLOCK subqueues to sch_mqJohn Fastabend2-11/+23
The sch_mq qdisc creates a sub-qdisc per tx queue which are then called independently for enqueue and dequeue operations. However statistics are aggregated and pushed up to the "master" qdisc. This patch adds support for any of the sub-qdiscs to be per cpu statistic qdiscs. To handle this case add a check when calculating stats and aggregate the per cpu stats if needed. Also exports __gnet_stats_copy_queue() to use as a helper function. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08net: sched: helpers to sum qlen and qlen for per cpu logicJohn Fastabend1-1/+2
Add qdisc qlen helper routines for lockless qdiscs to use. The qdisc qlen is no longer used in the hotpath but it is reported via stats query on the qdisc so it still needs to be tracked. This adds the per cpu operations needed along with a helper to return the summation of per cpu stats. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08net: sched: check for frozen queue before skb_bad_txq checkJohn Fastabend1-4/+7
I can not think of any reason to pull the bad txq skb off the qdisc if the txq we plan to send this on is still frozen. So check for frozen queue first and abort before dequeuing either skb_bad_txq skb or normal qdisc dequeue() skb. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08net: sched: use skb list for skb_bad_txJohn Fastabend1-20/+86
Similar to how gso is handled use skb list for skb_bad_tx this is required with lockless qdiscs because we may have multiple cores attempting to push skbs into skb_bad_tx concurrently Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08net: sched: drop qdisc_reset from dev_graft_qdiscJohn Fastabend1-9/+19
In qdisc_graft_qdisc a "new" qdisc is attached and the 'qdisc_destroy' operation is called on the old qdisc. The destroy operation will wait a rcu grace period and call qdisc_rcu_free(). At which point gso_cpu_skb is free'd along with all stats so no need to zero stats and gso_cpu_skb from the graft operation itself. Further after dropping the qdisc locks we can not continue to call qdisc_reset before waiting an rcu grace period so that the qdisc is detached from all cpus. By removing the qdisc_reset() here we get the correct property of waiting an rcu grace period and letting the qdisc_destroy operation clean up the qdisc correctly. Note, a refcnt greater than 1 would cause the destroy operation to be aborted however if this ever happened the reference to the qdisc would be lost and we would have a memory leak. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08net: sched: explicit locking in gso_cpu fallbackJohn Fastabend1-13/+72
This work is preparing the qdisc layer to support egress lockless qdiscs. If we are running the egress qdisc lockless in the case we overrun the netdev, for whatever reason, the netdev returns a busy error code and the skb is parked on the gso_skb pointer. With many cores all hitting this case at once its possible to have multiple sk_buffs here so we turn gso_skb into a queue. This should be the edge case and if we see this frequently then the netdev/qdisc layer needs to back off. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08net: sched: a dflt qdisc may be used with per cpu statsJohn Fastabend1-0/+16
Enable dflt qdisc support for per cpu stats before this patch a dflt qdisc was required to use the global statistics qstats and bstats. This adds a static flags field to qdisc_ops that is propagated into qdisc->flags in qdisc allocate call. This allows the allocation block to completely allocate the qdisc object so we don't have dangling allocations after qdisc init. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08net: sched: remove remaining uses for qdisc_qlen in xmit pathJohn Fastabend1-15/+13
sch_direct_xmit() uses qdisc_qlen as a return value but all call sites of the routine only check if it is zero or not. Simplify the logic so that we don't need to return an actual queue length value. This introduces a case now where sch_direct_xmit would have returned a qlen of zero but now it returns true. However in this case all call sites of sch_direct_xmit will implement a dequeue() and get a null skb and abort. This trades tracking qlen in the hotpath for an extra dequeue operation. Overall this seems to be good for performance. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08net: sched: allow qdiscs to handle lockingJohn Fastabend2-14/+42
This patch adds a flag for queueing disciplines to indicate the stack does not need to use the qdisc lock to protect operations. This can be used to build lockless scheduling algorithms and improving performance. The flag is checked in the tx path and the qdisc lock is only taken if it is not set. For now use a conditional if statement. Later we could be more aggressive if it proves worthwhile and use a static key or wrap this in a likely(). Also the lockless case drops the TCQ_F_CAN_BYPASS logic. The reason for this is synchronizing a qlen counter across threads proves to cost more than doing the enqueue/dequeue operations when tested with pktgen. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08net: sched: cleanup qdisc_run and __qdisc_run semanticsJohn Fastabend2-4/+3
Currently __qdisc_run calls qdisc_run_end() but does not call qdisc_run_begin(). This makes it hard to track pairs of qdisc_run_{begin,end} across function calls. To simplify reading these code paths this patch moves begin/end calls into qdisc_run(). Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08tcp_bbr: reset long-term bandwidth sampling on loss recovery undoNeal Cardwell1-0/+1
Fix BBR so that upon notification of a loss recovery undo BBR resets long-term bandwidth sampling. Under high reordering, reordering events can be interpreted as loss. If the reordering and spurious loss estimates are high enough, this can cause BBR to spuriously estimate that we are seeing loss rates high enough to trigger long-term bandwidth estimation. To avoid that problem, this commit resets long-term bandwidth sampling on loss recovery undo events. Signed-off-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Yuchung Cheng <ycheng@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08tcp_bbr: reset full pipe detection on loss recovery undoNeal Cardwell1-0/+4
Fix BBR so that upon notification of a loss recovery undo BBR resets the full pipe detection (STARTUP exit) state machine. Under high reordering, reordering events can be interpreted as loss. If the reordering and spurious loss estimates are high enough, this could previously cause BBR to spuriously estimate that the pipe is full. Since spurious loss recovery means that our overall sending will have slowed down spuriously, this commit gives a flow more time to probe robustly for bandwidth and decide the pipe is really full. Signed-off-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Yuchung Cheng <ycheng@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08tcp_bbr: record "full bw reached" decision in new full_bw_reached bitNeal Cardwell1-2/+5
This commit records the "full bw reached" decision in a new full_bw_reached bit. This is a pure refactor that does not change the current behavior, but enables subsequent fixes and improvements. In particular, this enables simple and clean fixes because the full_bw and full_bw_cnt can be unconditionally zeroed without worrying about forgetting that we estimated we filled the pipe in Startup. And it enables future improvements because multiple code paths can be used for estimating that we filled the pipe in Startup; any new code paths only need to set this bit when they think the pipe is full. Note that this fix intentionally reduces the width of the full_bw_cnt counter, since we have never used the most significant bit. Signed-off-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Yuchung Cheng <ycheng@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller1-3/+38
Alexei Starovoitov says: ==================== pull-request: bpf-next 2017-12-07 The following pull-request contains BPF updates for your net-next tree. The main changes are: 1) Detailed documentation of BPF development process from Daniel. 2) Addition of is_fullsock, snd_cwnd and srtt_us fields to bpf_sock_ops from Lawrence. 3) Minor follow up for bpf_skb_set_tunnel_key() from William. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08tcp: invalidate rate samples during SACK renegingYousuk Seung3-5/+16
Mark tcp_sock during a SACK reneging event and invalidate rate samples while marked. Such rate samples may overestimate bw by including packets that were SACKed before reneging. < ack 6001 win 10000 sack 7001:38001 < ack 7001 win 0 sack 8001:38001 // Reneg detected > seq 7001:8001 // RTO, SACK cleared. < ack 38001 win 10000 In above example the rate sample taken after the last ack will count 7001-38001 as delivered while the actual delivery rate likely could be much lower i.e. 7001-8001. This patch adds a new field tcp_sock.sack_reneg and marks it when we declare SACK reneging and entering TCP_CA_Loss, and unmarks it after the last rate sample was taken before moving back to TCP_CA_Open. This patch also invalidates rate samples taken while tcp_sock.is_sack_reneg is set. Fixes: b9f64820fb22 ("tcp: track data delivery rate for a TCP connection") Signed-off-by: Yousuk Seung <ysseung@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Priyaranjan Jha <priyarjha@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-07smc: support variable CLC proposal messagesUrsula Braun3-24/+107
According to RFC7609 [1] the CLC proposal message contains an area of unknown length for future growth. Additionally it may contain up to 8 IPv6 prefixes. The current version of the SMC-code does not understand CLC proposal messages using these variable length fields and, thus, is incompatible with SMC implementations in other operating systems. This patch makes sure, SMC understands incoming CLC proposals * with arbitrary length values for future growth * with up to 8 IPv6 prefixes [1] SMC-R Informational RFC: http://www.rfc-editor.org/info/rfc7609 Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Reviewed-by: Hans Wippel <hwippel@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-07smc: no consumer update in tasklet contextUrsula Braun2-16/+5
The SMC protocol requires to send a separate consumer cursor update, if it cannot be piggybacked to updates of the producer cursor. When receiving a blocked signal from the sender, this update is sent already in tasklet context. In addition consumer cursor updates are sent after data receival. Sending of cursor updates is controlled by sequence numbers. Assuming receiving stray messages the receiver drops updates with older sequence numbers than an already received cursor update with a higher sequence number. Sending consumer cursor updates in tasklet context may result in wrong order sends and its corresponding drops at the receiver. Since it is sufficient to send consumer cursor updates once the data is received, this patch gets rid of the consumer cursor update in tasklet context to guarantee in-sequence arrival of cursor updates. Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-07smc: cleanup close checking during data receivalUrsula Braun1-4/+1
When waiting for data to be received it must be checked if the peer signals shutdown. The SMC code uses two different checks for this purpose, even though just one check is sufficient. This patch removes the superfluous test for SOCK_DONE. Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-07smc: no update for unused sk_write_pendingUrsula Braun1-2/+0
The smc code never checks the sk_write_pending sock field. Thus there is no need to update it. Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-07smc: improve smc_clc_send_decline() error handlingUrsula Braun2-7/+4
Let smc_clc_send_decline() return with an error, if the amount sent is smaller than the length of an smc decline message. Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-07smc: make smc_close_active_abort() staticUrsula Braun2-2/+1
smc_close_active_abort() is used in smc_close.c only. Make it static. Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-07tcp: use current time in tcp_rcv_space_adjust()Eric Dumazet1-0/+1
When I switched rcv_rtt_est to high resolution timestamps, I forgot that tp->tcp_mstamp needed to be refreshed in tcp_rcv_space_adjust() Using an old timestamp leads to autotuning lags. Fixes: 645f4c6f2ebd ("tcp: switch rcv_rtt_est and rcvq_space to high resolution timestamps") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Wei Wang <weiwan@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>