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2014-10-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: "A quick batch of bug fixes: 1) Fix build with IPV6 disabled, from Eric Dumazet. 2) Several more cases of caching SKB data pointers across calls to pskb_may_pull(), thus referencing potentially free'd memory. From Li RongQing. 3) DSA phy code tests operation presence improperly, instead of going: if (x->ops->foo) r = x->ops->foo(args); it was going: if (x->ops->foo(args)) r = x->ops->foo(args); Fix from Andew Lunn" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: Net: DSA: Fix checking for get_phy_flags function ipv6: fix a potential use after free in sit.c ipv6: fix a potential use after free in ip6_offload.c ipv4: fix a potential use after free in gre_offload.c tcp: fix build error if IPv6 is not enabled
2014-10-18ipv4: fix a potential use after free in gre_offload.cLi RongQing
pskb_may_pull() may change skb->data and make greh pointer oboslete; so need to reassign greh; but since first calling pskb_may_pull already ensured that skb->data has enough space for greh, so move the reference of greh before second calling pskb_may_pull(), to avoid reassign greh. Fixes: 7a7ffbabf9("ipv4: fix tunneled VM traffic over hw VXLAN/GRE GSO NIC") Cc: Wei-Chun Chao <weichunc@plumgrid.com> Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) Include fixes for netrom and dsa (Fabian Frederick and Florian Fainelli) 2) Fix FIXED_PHY support in stmmac, from Giuseppe CAVALLARO. 3) Several SKB use after free fixes (vxlan, openvswitch, vxlan, ip_tunnel, fou), from Li ROngQing. 4) fec driver PTP support fixes from Luwei Zhou and Nimrod Andy. 5) Use after free in virtio_net, from Michael S Tsirkin. 6) Fix flow mask handling for megaflows in openvswitch, from Pravin B Shelar. 7) ISDN gigaset and capi bug fixes from Tilman Schmidt. 8) Fix route leak in ip_send_unicast_reply(), from Vasily Averin. 9) Fix two eBPF JIT bugs on x86, from Alexei Starovoitov. 10) TCP_SKB_CB() reorganization caused a few regressions, fixed by Cong Wang and Eric Dumazet. 11) Don't overwrite end of SKB when parsing malformed sctp ASCONF chunks, from Daniel Borkmann. 12) Don't call sock_kfree_s() with NULL pointers, this function also has the side effect of adjusting the socket memory usage. From Cong Wang. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (90 commits) bna: fix skb->truesize underestimation net: dsa: add includes for ethtool and phy_fixed definitions openvswitch: Set flow-key members. netrom: use linux/uaccess.h dsa: Fix conversion from host device to mii bus tipc: fix bug in bundled buffer reception ipv6: introduce tcp_v6_iif() sfc: add support for skb->xmit_more r8152: return -EBUSY for runtime suspend ipv4: fix a potential use after free in fou.c ipv4: fix a potential use after free in ip_tunnel_core.c hyperv: Add handling of IP header with option field in netvsc_set_hash() openvswitch: Create right mask with disabled megaflows vxlan: fix a free after use openvswitch: fix a use after free ipv4: dst_entry leak in ip_send_unicast_reply() ipv4: clean up cookie_v4_check() ipv4: share tcp_v4_save_options() with cookie_v4_check() ipv4: call __ip_options_echo() in cookie_v4_check() atm: simplify lanai.c by using module_pci_driver ...
2014-10-18ipv4: fix a potential use after free in fou.cLi RongQing
pskb_may_pull() maybe change skb->data and make uh pointer oboslete, so reload uh and guehdr Fixes: 37dd0247 ("gue: Receive side for Generic UDP Encapsulation") Cc: Tom Herbert <therbert@google.com> Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-18ipv4: fix a potential use after free in ip_tunnel_core.cLi RongQing
pskb_may_pull() maybe change skb->data and make eth pointer oboslete, so set eth after pskb_may_pull() Fixes:3d7b46cd("ip_tunnel: push generic protocol handling to ip_tunnel module") Cc: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Acked-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-17ipv4: dst_entry leak in ip_send_unicast_reply()Vasily Averin
ip_setup_cork() called inside ip_append_data() steals dst entry from rt to cork and in case errors in __ip_append_data() nobody frees stolen dst entry Fixes: 2e77d89b2fa8 ("net: avoid a pair of dst_hold()/dst_release() in ip_append_data()") Signed-off-by: Vasily Averin <vvs@parallels.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-17ipv4: clean up cookie_v4_check()Cong Wang
We can retrieve opt from skb, no need to pass it as a parameter. And opt should always be non-NULL, no need to check. Cc: Krzysztof Kolasa <kkolasa@winsoft.pl> Cc: Eric Dumazet <edumazet@google.com> Tested-by: Krzysztof Kolasa <kkolasa@winsoft.pl> Signed-off-by: Cong Wang <cwang@twopensource.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-17ipv4: share tcp_v4_save_options() with cookie_v4_check()Cong Wang
cookie_v4_check() allocates ip_options_rcu in the same way with tcp_v4_save_options(), we can just make it a helper function. Cc: Krzysztof Kolasa <kkolasa@winsoft.pl> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Cong Wang <cwang@twopensource.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-17ipv4: call __ip_options_echo() in cookie_v4_check()Cong Wang
commit 971f10eca186cab238c49da ("tcp: better TCP_SKB_CB layout to reduce cache line misses") missed that cookie_v4_check() still calls ip_options_echo() which uses IPCB(). It should use TCPCB() at TCP layer, so call __ip_options_echo() instead. Fixes: commit 971f10eca186cab238c49da ("tcp: better TCP_SKB_CB layout to reduce cache line misses") Cc: Krzysztof Kolasa <kkolasa@winsoft.pl> Cc: Eric Dumazet <edumazet@google.com> Reported-by: Krzysztof Kolasa <kkolasa@winsoft.pl> Tested-by: Krzysztof Kolasa <kkolasa@winsoft.pl> Signed-off-by: Cong Wang <cwang@twopensource.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-15Merge branch 'for-3.18-consistent-ops' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu Pull percpu consistent-ops changes from Tejun Heo: "Way back, before the current percpu allocator was implemented, static and dynamic percpu memory areas were allocated and handled separately and had their own accessors. The distinction has been gone for many years now; however, the now duplicate two sets of accessors remained with the pointer based ones - this_cpu_*() - evolving various other operations over time. During the process, we also accumulated other inconsistent operations. This pull request contains Christoph's patches to clean up the duplicate accessor situation. __get_cpu_var() uses are replaced with with this_cpu_ptr() and __this_cpu_ptr() with raw_cpu_ptr(). Unfortunately, the former sometimes is tricky thanks to C being a bit messy with the distinction between lvalues and pointers, which led to a rather ugly solution for cpumask_var_t involving the introduction of this_cpu_cpumask_var_ptr(). This converts most of the uses but not all. Christoph will follow up with the remaining conversions in this merge window and hopefully remove the obsolete accessors" * 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (38 commits) irqchip: Properly fetch the per cpu offset percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t -fix ia64: sn_nodepda cannot be assigned to after this_cpu conversion. Use __this_cpu_write. percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t Revert "powerpc: Replace __get_cpu_var uses" percpu: Remove __this_cpu_ptr clocksource: Replace __this_cpu_ptr with raw_cpu_ptr sparc: Replace __get_cpu_var uses avr32: Replace __get_cpu_var with __this_cpu_write blackfin: Replace __get_cpu_var uses tile: Use this_cpu_ptr() for hardware counters tile: Replace __get_cpu_var uses powerpc: Replace __get_cpu_var uses alpha: Replace __get_cpu_var ia64: Replace __get_cpu_var uses s390: cio driver &__get_cpu_var replacements s390: Replace __get_cpu_var uses mips: Replace __get_cpu_var uses MIPS: Replace __get_cpu_var uses in FPU emulator. arm: Replace __this_cpu_ptr with raw_cpu_ptr ...
2014-10-14tcp: TCP Small Queues and strange attractorsEric Dumazet
TCP Small queues tries to keep number of packets in qdisc as small as possible, and depends on a tasklet to feed following packets at TX completion time. Choice of tasklet was driven by latencies requirements. Then, TCP stack tries to avoid reorders, by locking flows with outstanding packets in qdisc in a given TX queue. What can happen is that many flows get attracted by a low performing TX queue, and cpu servicing TX completion has to feed packets for all of them, making this cpu 100% busy in softirq mode. This became particularly visible with latest skb->xmit_more support Strategy adopted in this patch is to detect when tcp_wfree() is called from ksoftirqd and let the outstanding queue for this flow being drained before feeding additional packets, so that skb->ooo_okay can be set to allow select_queue() to select the optimal queue : Incoming ACKS are normally handled by different cpus, so this patch gives more chance for these cpus to take over the burden of feeding qdisc with future packets. Tested: lpaa23:~# ./super_netperf 1400 --google-pacing-rate 3028000 -H lpaa24 -l 3600 & lpaa23:~# sar -n DEV 1 10 | grep eth1 06:16:18 AM eth1 595448.00 1190564.00 38381.09 1760253.12 0.00 0.00 1.00 06:16:19 AM eth1 594858.00 1189686.00 38340.76 1758952.72 0.00 0.00 0.00 06:16:20 AM eth1 597017.00 1194019.00 38480.79 1765370.29 0.00 0.00 1.00 06:16:21 AM eth1 595450.00 1190936.00 38380.19 1760805.05 0.00 0.00 0.00 06:16:22 AM eth1 596385.00 1193096.00 38442.56 1763976.29 0.00 0.00 1.00 06:16:23 AM eth1 598155.00 1195978.00 38552.97 1768264.60 0.00 0.00 0.00 06:16:24 AM eth1 594405.00 1188643.00 38312.57 1757414.89 0.00 0.00 1.00 06:16:25 AM eth1 593366.00 1187154.00 38252.16 1755195.83 0.00 0.00 0.00 06:16:26 AM eth1 593188.00 1186118.00 38232.88 1753682.57 0.00 0.00 1.00 06:16:27 AM eth1 596301.00 1192241.00 38440.94 1762733.09 0.00 0.00 0.00 Average: eth1 595457.30 1190843.50 38381.69 1760664.84 0.00 0.00 0.50 lpaa23:~# ./tc -s -d qd sh dev eth1 | grep backlog backlog 7606336b 2513p requeues 167982 backlog 224072b 74p requeues 566 backlog 581376b 192p requeues 5598 backlog 181680b 60p requeues 1070 backlog 5305056b 1753p requeues 110166 // Here, this TX queue is attracting flows backlog 157456b 52p requeues 1758 backlog 672216b 222p requeues 3025 backlog 60560b 20p requeues 24541 backlog 448144b 148p requeues 21258 lpaa23:~# echo 1 >/proc/sys/net/ipv4/tcp_tsq_enable_tcp_wfree_ksoftirqd_detect Immediate jump to full bandwidth, and traffic is properly shard on all tx queues. lpaa23:~# sar -n DEV 1 10 | grep eth1 06:16:46 AM eth1 1397632.00 2795397.00 90081.87 4133031.26 0.00 0.00 1.00 06:16:47 AM eth1 1396874.00 2793614.00 90032.99 4130385.46 0.00 0.00 0.00 06:16:48 AM eth1 1395842.00 2791600.00 89966.46 4127409.67 0.00 0.00 1.00 06:16:49 AM eth1 1395528.00 2791017.00 89946.17 4126551.24 0.00 0.00 0.00 06:16:50 AM eth1 1397891.00 2795716.00 90098.74 4133497.39 0.00 0.00 1.00 06:16:51 AM eth1 1394951.00 2789984.00 89908.96 4125022.51 0.00 0.00 0.00 06:16:52 AM eth1 1394608.00 2789190.00 89886.90 4123851.36 0.00 0.00 1.00 06:16:53 AM eth1 1395314.00 2790653.00 89934.33 4125983.09 0.00 0.00 0.00 06:16:54 AM eth1 1396115.00 2792276.00 89984.25 4128411.21 0.00 0.00 1.00 06:16:55 AM eth1 1396829.00 2793523.00 90030.19 4130250.28 0.00 0.00 0.00 Average: eth1 1396158.40 2792297.00 89987.09 4128439.35 0.00 0.00 0.50 lpaa23:~# tc -s -d qd sh dev eth1 | grep backlog backlog 7900052b 2609p requeues 173287 backlog 878120b 290p requeues 589 backlog 1068884b 354p requeues 5621 backlog 996212b 329p requeues 1088 backlog 984100b 325p requeues 115316 backlog 956848b 316p requeues 1781 backlog 1080996b 357p requeues 3047 backlog 975016b 322p requeues 24571 backlog 990156b 327p requeues 21274 (All 8 TX queues get a fair share of the traffic) Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-14ipv4: fix nexthop attlen check in fib_nh_matchJiri Pirko
fib_nh_match does not match nexthops correctly. Example: ip route add 172.16.10/24 nexthop via 192.168.122.12 dev eth0 \ nexthop via 192.168.122.13 dev eth0 ip route del 172.16.10/24 nexthop via 192.168.122.14 dev eth0 \ nexthop via 192.168.122.15 dev eth0 Del command is successful and route is removed. After this patch applied, the route is correctly matched and result is: RTNETLINK answers: No such process Please consider this for stable trees as well. Fixes: 4e902c57417c4 ("[IPv4]: FIB configuration using struct fib_config") Signed-off-by: Jiri Pirko <jiri@resnulli.us> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-14tcp: fix tcp_ack() performance problemEric Dumazet
We worked hard to improve tcp_ack() performance, by not accessing skb_shinfo() in fast path (cd7d8498c9a5 tcp: change tcp_skb_pcount() location) We still have one spurious access because of ACK timestamping, added in commit e1c8a607b281 ("net-timestamp: ACK timestamp for bytestreams") By checking if sk_tsflags has SOF_TIMESTAMPING_TX_ACK set, we can avoid two cache line misses for the common case. While we are at it, add two prefetchw() : One in tcp_ack() to bring skb at the head of write queue. One in tcp_clean_rtx_queue() loop to bring following skb, as we will delete skb from the write queue and dirty skb->next->prev. Add a couple of [un]likely() clauses. After this patch, tcp_ack() is no longer the most consuming function in tcp stack. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Van Jacobson <vanj@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-14tcp: fix ooo_okay setting vs Small QueuesEric Dumazet
TCP Small Queues (tcp_tsq_handler()) can hold one reference on sk->sk_wmem_alloc, preventing skb->ooo_okay being set. We should relax test done to set skb->ooo_okay to take care of this extra reference. Minimal truesize of skb containing one byte of payload is SKB_TRUESIZE(1) Without this fix, we have more chance locking flows into the wrong transmit queue. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-10Merge branch 'for-3.18' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu Pull percpu updates from Tejun Heo: "A lot of activities on percpu front. Notable changes are... - percpu allocator now can take @gfp. If @gfp doesn't contain GFP_KERNEL, it tries to allocate from what's already available to the allocator and a work item tries to keep the reserve around certain level so that these atomic allocations usually succeed. This will replace the ad-hoc percpu memory pool used by blk-throttle and also be used by the planned blkcg support for writeback IOs. Please note that I noticed a bug in how @gfp is interpreted while preparing this pull request and applied the fix 6ae833c7fe0c ("percpu: fix how @gfp is interpreted by the percpu allocator") just now. - percpu_ref now uses longs for percpu and global counters instead of ints. It leads to more sparse packing of the percpu counters on 64bit machines but the overhead should be negligible and this allows using percpu_ref for refcnting pages and in-memory objects directly. - The switching between percpu and single counter modes of a percpu_ref is made independent of putting the base ref and a percpu_ref can now optionally be initialized in single or killed mode. This allows avoiding percpu shutdown latency for cases where the refcounted objects may be synchronously created and destroyed in rapid succession with only a fraction of them reaching fully operational status (SCSI probing does this when combined with blk-mq support). It's also planned to be used to implement forced single mode to detect underflow more timely for debugging. There's a separate branch percpu/for-3.18-consistent-ops which cleans up the duplicate percpu accessors. That branch causes a number of conflicts with s390 and other trees. I'll send a separate pull request w/ resolutions once other branches are merged" * 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (33 commits) percpu: fix how @gfp is interpreted by the percpu allocator blk-mq, percpu_ref: start q->mq_usage_counter in atomic mode percpu_ref: make INIT_ATOMIC and switch_to_atomic() sticky percpu_ref: add PERCPU_REF_INIT_* flags percpu_ref: decouple switching to percpu mode and reinit percpu_ref: decouple switching to atomic mode and killing percpu_ref: add PCPU_REF_DEAD percpu_ref: rename things to prepare for decoupling percpu/atomic mode switch percpu_ref: replace pcpu_ prefix with percpu_ percpu_ref: minor code and comment updates percpu_ref: relocate percpu_ref_reinit() Revert "blk-mq, percpu_ref: implement a kludge for SCSI blk-mq stall during probe" Revert "percpu: free percpu allocation info for uniprocessor system" percpu-refcount: make percpu_ref based on longs instead of ints percpu-refcount: improve WARN messages percpu: fix locking regression in the failure path of pcpu_alloc() percpu-refcount: add @gfp to percpu_ref_init() proportions: add @gfp to init functions percpu_counter: add @gfp to percpu_counter_init() percpu_counter: make percpu_counters_lock irq-safe ...
2014-10-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: "Most notable changes in here: 1) By far the biggest accomplishment, thanks to a large range of contributors, is the addition of multi-send for transmit. This is the result of discussions back in Chicago, and the hard work of several individuals. Now, when the ->ndo_start_xmit() method of a driver sees skb->xmit_more as true, it can choose to defer the doorbell telling the driver to start processing the new TX queue entires. skb->xmit_more means that the generic networking is guaranteed to call the driver immediately with another SKB to send. There is logic added to the qdisc layer to dequeue multiple packets at a time, and the handling mis-predicted offloads in software is now done with no locks held. Finally, pktgen is extended to have a "burst" parameter that can be used to test a multi-send implementation. Several drivers have xmit_more support: i40e, igb, ixgbe, mlx4, virtio_net Adding support is almost trivial, so export more drivers to support this optimization soon. I want to thank, in no particular or implied order, Jesper Dangaard Brouer, Eric Dumazet, Alexander Duyck, Tom Herbert, Jamal Hadi Salim, John Fastabend, Florian Westphal, Daniel Borkmann, David Tat, Hannes Frederic Sowa, and Rusty Russell. 2) PTP and timestamping support in bnx2x, from Michal Kalderon. 3) Allow adjusting the rx_copybreak threshold for a driver via ethtool, and add rx_copybreak support to enic driver. From Govindarajulu Varadarajan. 4) Significant enhancements to the generic PHY layer and the bcm7xxx driver in particular (EEE support, auto power down, etc.) from Florian Fainelli. 5) Allow raw buffers to be used for flow dissection, allowing drivers to determine the optimal "linear pull" size for devices that DMA into pools of pages. The objective is to get exactly the necessary amount of headers into the linear SKB area pre-pulled, but no more. The new interface drivers use is eth_get_headlen(). From WANG Cong, with driver conversions (several had their own by-hand duplicated implementations) by Alexander Duyck and Eric Dumazet. 6) Support checksumming more smoothly and efficiently for encapsulations, and add "foo over UDP" facility. From Tom Herbert. 7) Add Broadcom SF2 switch driver to DSA layer, from Florian Fainelli. 8) eBPF now can load programs via a system call and has an extensive testsuite. Alexei Starovoitov and Daniel Borkmann. 9) Major overhaul of the packet scheduler to use RCU in several major areas such as the classifiers and rate estimators. From John Fastabend. 10) Add driver for Intel FM10000 Ethernet Switch, from Alexander Duyck. 11) Rearrange TCP_SKB_CB() to reduce cache line misses, from Eric Dumazet. 12) Add Datacenter TCP congestion control algorithm support, From Florian Westphal. 13) Reorganize sk_buff so that __copy_skb_header() is significantly faster. From Eric Dumazet" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1558 commits) netlabel: directly return netlbl_unlabel_genl_init() net: add netdev_txq_bql_{enqueue, complete}_prefetchw() helpers net: description of dma_cookie cause make xmldocs warning cxgb4: clean up a type issue cxgb4: potential shift wrapping bug i40e: skb->xmit_more support net: fs_enet: Add NAPI TX net: fs_enet: Remove non NAPI RX r8169:add support for RTL8168EP net_sched: copy exts->type in tcf_exts_change() wimax: convert printk to pr_foo() af_unix: remove 0 assignment on static ipv6: Do not warn for informational ICMP messages, regardless of type. Update Intel Ethernet Driver maintainers list bridge: Save frag_max_size between PRE_ROUTING and POST_ROUTING tipc: fix bug in multicast congestion handling net: better IFF_XMIT_DST_RELEASE support net/mlx4_en: remove NETDEV_TX_BUSY 3c59x: fix bad split of cpu_to_le32(pci_map_single()) net: bcmgenet: fix Tx ring priority programming ...
2014-10-08Merge tag 'dmaengine-3.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/dmaengine Pull dmaengine updates from Dan Williams: "Even though this has fixes marked for -stable, given the size and the needed conflict resolutions this is 3.18-rc1/merge-window material. These patches have been languishing in my tree for a long while. The fact that I do not have the time to do proper/prompt maintenance of this tree is a primary factor in the decision to step down as dmaengine maintainer. That and the fact that the bulk of drivers/dma/ activity is going through Vinod these days. The net_dma removal has not been in -next. It has developed simple conflicts against mainline and net-next (for-3.18). Continuing thanks to Vinod for staying on top of drivers/dma/. Summary: 1/ Step down as dmaengine maintainer see commit 08223d80df38 "dmaengine maintainer update" 2/ Removal of net_dma, as it has been marked 'broken' since 3.13 (commit 77873803363c "net_dma: mark broken"), without reports of performance regression. 3/ Miscellaneous fixes" * tag 'dmaengine-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/dmaengine: net: make tcp_cleanup_rbuf private net_dma: revert 'copied_early' net_dma: simple removal dmaengine maintainer update dmatest: prevent memory leakage on error path in thread ioat: Use time_before_jiffies() dmaengine: fix xor sources continuation dma: mv_xor: Rename __mv_xor_slot_cleanup() to mv_xor_slot_cleanup() dma: mv_xor: Remove all callers of mv_xor_slot_cleanup() dma: mv_xor: Remove unneeded mv_xor_clean_completed_slots() call ioat: Use pci_enable_msix_exact() instead of pci_enable_msix() drivers: dma: Include appropriate header file in dca.c drivers: dma: Mark functions as static in dma_v3.c dma: mv_xor: Add DMA API error checks ioat/dca: Use dev_is_pci() to check whether it is pci device
2014-10-07net: better IFF_XMIT_DST_RELEASE supportEric Dumazet
Testing xmit_more support with netperf and connected UDP sockets, I found strange dst refcount false sharing. Current handling of IFF_XMIT_DST_RELEASE is not optimal. Dropping dst in validate_xmit_skb() is certainly too late in case packet was queued by cpu X but dequeued by cpu Y The logical point to take care of drop/force is in __dev_queue_xmit() before even taking qdisc lock. As Julian Anastasov pointed out, need for skb_dst() might come from some packet schedulers or classifiers. This patch adds new helper to cleanly express needs of various drivers or qdiscs/classifiers. Drivers that need skb_dst() in their ndo_start_xmit() should call following helper in their setup instead of the prior : dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; -> netif_keep_dst(dev); Instead of using a single bit, we use two bits, one being eventually rebuilt in bonding/team drivers. The other one, is permanent and blocks IFF_XMIT_DST_RELEASE being rebuilt in bonding/team. Eventually, we could add something smarter later. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-07openvswitch: fix a compilation error when CONFIG_INET is not setW!Andy Zhou
Fix a openvswitch compilation error when CONFIG_INET is not set: ===================================================== In file included from include/net/geneve.h:4:0, from net/openvswitch/flow_netlink.c:45: include/net/udp_tunnel.h: In function 'udp_tunnel_handle_offloads': >> include/net/udp_tunnel.h:100:2: error: implicit declaration of function 'iptunnel_handle_offloads' [-Werror=implicit-function-declaration] >> return iptunnel_handle_offloads(skb, udp_csum, type); >> ^ >> >> include/net/udp_tunnel.h:100:2: warning: return makes pointer from integer without a cast >> >> cc1: some warnings being treated as errors ===================================================== Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Andy Zhou <azhou@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-07net: fix a sparse warningAndy Zhou
Fix a sparse warning introduced by Commit 0b5e8b8eeae40bae6ad7c7e91c97c3c0d0e57882 (net: Add Geneve tunneling protocol driver) caught by kbuild test robot: # apt-get install sparse # git checkout 0b5e8b8eeae40bae6ad7c7e91c97c3c0d0e57882 # make ARCH=x86_64 allmodconfig # make C=1 CF=-D__CHECK_ENDIAN__ # # # sparse warnings: (new ones prefixed by >>) # # >> net/ipv4/geneve.c:230:42: sparse: incorrect type in assignment (different base types) # net/ipv4/geneve.c:230:42: expected restricted __be32 [addressable] [assigned] [usertype] s_addr # net/ipv4/geneve.c:230:42: got unsigned long [unsigned] <noident> # Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Andy Zhou <azhou@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-06ipv4: igmp: fix v3 general query drop monitor false positiveDaniel Borkmann
In case we find a general query with non-zero number of sources, we are dropping the skb as it's malformed. RFC3376, section 4.1.8. Number of Sources (N): This number is zero in a General Query or a Group-Specific Query, and non-zero in a Group-and-Source-Specific Query. Therefore, reflect that by using kfree_skb() instead of consume_skb(). Fixes: d679c5324d9a ("igmp: avoid drop_monitor false positives") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-06net: Add Geneve tunneling protocol driverAndy Zhou
This adds a device level support for Geneve -- Generic Network Virtualization Encapsulation. The protocol is documented at http://tools.ietf.org/html/draft-gross-geneve-01 Only protocol layer Geneve support is provided by this driver. Openvswitch can be used for configuring, set up and tear down functional Geneve tunnels. Signed-off-by: Jesse Gross <jesse@nicira.com> Signed-off-by: Andy Zhou <azhou@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller
Pablo Neira Ayuso says: ==================== Netfilter/IPVS updates for net-next The following patchset contains another batch with Netfilter/IPVS updates for net-next, they are: 1) Add abstracted ICMP codes to the nf_tables reject expression. We introduce four reasons to reject using ICMP that overlap in IPv4 and IPv6 from the semantic point of view. This should simplify the maintainance of dual stack rule-sets through the inet table. 2) Move nf_send_reset() functions from header files to per-family nf_reject modules, suggested by Patrick McHardy. 3) We have to use IS_ENABLED(CONFIG_BRIDGE_NETFILTER) everywhere in the code now that br_netfilter can be modularized. Convert remaining spots in the network stack code. 4) Use rcu_barrier() in the nf_tables module removal path to ensure that we don't leave object that are still pending to be released via call_rcu (that may likely result in a crash). 5) Remove incomplete arch 32/64 compat from nft_compat. The original (bad) idea was to probe the word size based on the xtables match/target info size, but this assumption is wrong when you have to dump the information back to userspace. 6) Allow to filter from prerouting and postrouting in the nf_tables bridge. In order to emulate the ebtables NAT chains (which are actually simple filter chains with no special semantics), we have support filtering from this hooks too. 7) Add explicit module dependency between xt_physdev and br_netfilter. This provides a way to detect if the user needs br_netfilter from the configuration path. This should reduce the breakage of the br_netfilter modularization. 8) Cleanup coding style in ip_vs.h, from Simon Horman. 9) Fix crash in the recently added nf_tables masq expression. We have to register/unregister the notifiers to clean up the conntrack table entries from the module init/exit path, not from the rule addition / deletion path. From Arturo Borrero. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-03ip_tunnel: Add GUE supportTom Herbert
This patch allows configuring IPIP, sit, and GRE tunnels to use GUE. This is very similar to fou excpet that we need to insert the GUE header in addition to the UDP header on transmit. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-03gue: Receive side for Generic UDP EncapsulationTom Herbert
This patch adds support receiving for GUE packets in the fou module. The fou module now supports direct foo-over-udp (no encapsulation header) and GUE. To support this a type parameter is added to the fou netlink parameters. For a GUE socket we define gue_udp_recv, gue_gro_receive, and gue_gro_complete to handle the specifics of the GUE protocol. Most of the code to manage and configure sockets is common with the fou. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-03fou: eliminate IPv4,v6 specific GRO functionsTom Herbert
This patch removes fou[46]_gro_receive and fou[46]_gro_complete functions. The v4 or v6 variants were chosen for the UDP offloads based on the address family of the socket this is not necessary or correct. Alternatively, this patch adds is_ipv6 to napi_gro_skb. This is set in udp6_gro_receive and unset in udp4_gro_receive. In fou_gro_receive the value is used to select the correct inet_offloads for the protocol of the outer IP header. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-03ip_tunnel: Account for secondary encapsulation header in max_headroomTom Herbert
When adjusting max_header for the tunnel interface based on egress device we need to account for any extra bytes in secondary encapsulation (e.g. FOU). Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-03netfilter: nft_masq: register/unregister notifiers on module init/exitArturo Borrero
We have to register the notifiers in the masquerade expression from the the module _init and _exit path. This fixes crashes when removing the masquerade rule with no ipt_MASQUERADE support in place (which was masking the problem). Fixes: 9ba1f72 ("netfilter: nf_tables: add new nft_masq expression") Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-10-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/usb/r8152.c net/netfilter/nfnetlink.c Both r8152 and nfnetlink conflicts were simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-02netfilter: use IS_ENABLED(CONFIG_BRIDGE_NETFILTER)Pablo Neira Ayuso
In 34666d4 ("netfilter: bridge: move br_netfilter out of the core"), the bridge netfilter code has been modularized. Use IS_ENABLED instead of ifdef to cover the module case. Fixes: 34666d4 ("netfilter: bridge: move br_netfilter out of the core") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-10-02netfilter: move nf_send_resetX() code to nf_reject_ipvX modulesPablo Neira Ayuso
Move nf_send_reset() and nf_send_reset6() to nf_reject_ipv4 and nf_reject_ipv6 respectively. This code is shared by x_tables and nf_tables. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-10-02netfilter: nft_reject: introduce icmp code abstraction for inet and bridgePablo Neira Ayuso
This patch introduces the NFT_REJECT_ICMPX_UNREACH type which provides an abstraction to the ICMP and ICMPv6 codes that you can use from the inet and bridge tables, they are: * NFT_REJECT_ICMPX_NO_ROUTE: no route to host - network unreachable * NFT_REJECT_ICMPX_PORT_UNREACH: port unreachable * NFT_REJECT_ICMPX_HOST_UNREACH: host unreachable * NFT_REJECT_ICMPX_ADMIN_PROHIBITED: administratevely prohibited You can still use the specific codes when restricting the rule to match the corresponding layer 3 protocol. I decided to not overload the existing NFT_REJECT_ICMP_UNREACH to have different semantics depending on the table family and to allow the user to specify ICMP family specific codes if they restrict it to the corresponding family. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-10-02gre: Set inner protocol in v4 and v6 GRE transmitTom Herbert
Call skb_set_inner_protocol to set inner Ethernet protocol to protocol being encapsulation by GRE before tunnel_xmit. This is needed for GSO if UDP encapsulation (fou) is being done. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-02ipip: Set inner IP protocol in ipipTom Herbert
Call skb_set_inner_ipproto to set inner IP protocol to IPPROTO_IPV4 before tunnel_xmit. This is needed if UDP encapsulation (fou) is being done. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-02udp: Generalize skb_udp_segmentTom Herbert
skb_udp_segment is the function called from udp4_ufo_fragment to segment a UDP tunnel packet. This function currently assumes segmentation is transparent Ethernet bridging (i.e. VXLAN encapsulation). This patch generalizes the function to operate on either Ethertype or IP protocol. The inner_protocol field must be set to the protocol of the inner header. This can now be either an Ethertype or an IP protocol (in a union). A new flag in the skbuff indicates which type is effective. skb_set_inner_protocol and skb_set_inner_ipproto helper functions were added to set the inner_protocol. These functions are called from the point where the tunnel encapsulation is occuring. When skb_udp_tunnel_segment is called, the function to segment the inner packet is selected based on the inner IP or Ethertype. In the case of an IP protocol encapsulation, the function is derived from inet[6]_offloads. In the case of Ethertype, skb->protocol is set to the inner_protocol and skb_mac_gso_segment is called. (GRE currently does this, but it might be possible to lookup the protocol in offload_base and call the appropriate segmenation function directly). Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-01net: cleanup and document skb fclone layoutEric Dumazet
Lets use a proper structure to clearly document and implement skb fast clones. Then, we might experiment more easily alternative layouts. This patch adds a new skb_fclone_busy() helper, used by tcp and xfrm, to stop leaking of implementation details. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-01tcp: abort orphan sockets stalling on zero window probesYuchung Cheng
Currently we have two different policies for orphan sockets that repeatedly stall on zero window ACKs. If a socket gets a zero window ACK when it is transmitting data, the RTO is used to probe the window. The socket is aborted after roughly tcp_orphan_retries() retries (as in tcp_write_timeout()). But if the socket was idle when it received the zero window ACK, and later wants to send more data, we use the probe timer to probe the window. If the receiver always returns zero window ACKs, icsk_probes keeps getting reset in tcp_ack() and the orphan socket can stall forever until the system reaches the orphan limit (as commented in tcp_probe_timer()). This opens up a simple attack to create lots of hanging orphan sockets to burn the memory and the CPU, as demonstrated in the recent netdev post "TCP connection will hang in FIN_WAIT1 after closing if zero window is advertised." http://www.spinics.net/lists/netdev/msg296539.html This patch follows the design in RTO-based probe: we abort an orphan socket stalling on zero window when the probe timer reaches both the maximum backoff and the maximum RTO. For example, an 100ms RTT connection will timeout after roughly 153 seconds (0.3 + 0.6 + .... + 76.8) if the receiver keeps the window shut. If the orphan socket passes this check, but the system already has too many orphans (as in tcp_out_of_resources()), we still abort it but we'll also send an RST packet as the connection may still be active. In addition, we change TCP_USER_TIMEOUT to cover (life or dead) sockets stalled on zero-window probes. This changes the semantics of TCP_USER_TIMEOUT slightly because it previously only applies when the socket has pending transmission. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Reported-by: Andrey Dmitrov <andrey.dmitrov@oktetlabs.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-01cipso: add __init to cipso_v4_cache_initFabian Frederick
cipso_v4_cache_init is only called by __init cipso_v4_init Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-01inet: frags: add __init to ip4_frags_ctl_registerFabian Frederick
ip4_frags_ctl_register is only called by __init ipfrag_init Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-01tcp: add __init to tcp_init_memFabian Frederick
tcp_init_mem is only called by __init tcp_init. Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-01ipv4: mentions skb_gro_postpull_rcsum() in inet_gro_receive()Eric Dumazet
Proper CHECKSUM_COMPLETE support needs to adjust skb->csum when we remove one header. Its done using skb_gro_postpull_rcsum() In the case of IPv4, we know that the adjustment is not really needed, because the checksum over IPv4 header is 0. Lets add a comment to ease code comprehension and avoid copy/paste errors. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-30tcp: Change tcp_slow_start function to return voidLi RongQing
No caller uses the return value, so make this function return void. Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller
Pablo Neira Ayuso says: ==================== pull request: netfilter/ipvs updates for net-next The following patchset contains Netfilter/IPVS updates for net-next, most relevantly they are: 1) Four patches to make the new nf_tables masquerading support independent of the x_tables infrastructure. This also resolves a compilation breakage if the masquerade target is disabled but the nf_tables masq expression is enabled. 2) ipset updates via Jozsef Kadlecsik. This includes the addition of the skbinfo extension that allows you to store packet metainformation in the elements. This can be used to fetch and restore this to the packets through the iptables SET target, patches from Anton Danilov. 3) Add the hash:mac set type to ipset, from Jozsef Kadlecsick. 4) Add simple weighted fail-over scheduler via Simon Horman. This provides a fail-over IPVS scheduler (unlike existing load balancing schedulers). Connections are directed to the appropriate server based solely on highest weight value and server availability, patch from Kenny Mathis. 5) Support IPv6 real servers in IPv4 virtual-services and vice versa. Simon Horman informs that the motivation for this is to allow more flexibility in the choice of IP version offered by both virtual-servers and real-servers as they no longer need to match: An IPv4 connection from an end-user may be forwarded to a real-server using IPv6 and vice versa. No ip_vs_sync support yet though. Patches from Alex Gartrell and Julian Anastasov. 6) Add global generation ID to the nf_tables ruleset. When dumping from several different object lists, we need a way to identify that an update has ocurred so userspace knows that it needs to refresh its lists. This also includes a new command to obtain the 32-bits generation ID. The less significant 16-bits of this ID is also exposed through res_id field in the nfnetlink header to quickly detect the interference and retry when there is no risk of ID wraparound. 7) Move br_netfilter out of the bridge core. The br_netfilter code is built in the bridge core by default. This causes problems of different kind to people that don't want this: Jesper reported performance drop due to the inconditional hook registration and I remember to have read complains on netdev from people regarding the unexpected behaviour of our bridging stack when br_netfilter is enabled (fragmentation handling, layer 3 and upper inspection). People that still need this should easily undo the damage by modprobing the new br_netfilter module. 8) Dump the set policy nf_tables that allows set parameterization. So userspace can keep user-defined preferences when saving the ruleset. From Arturo Borrero. 9) Use __seq_open_private() helper function to reduce boiler plate code in x_tables, From Rob Jones. 10) Safer default behaviour in case that you forget to load the protocol tracker. Daniel Borkmann and Florian Westphal detected that if your ruleset is stateful, you allow traffic to at least one single SCTP port and the SCTP protocol tracker is not loaded, then any SCTP traffic may be pass through unfiltered. After this patch, the connection tracking classifies SCTP/DCCP/UDPlite/GRE packets as invalid if your kernel has been compiled with support for these modules. ==================== Trivially resolved conflict in include/linux/skbuff.h, Eric moved some netfilter skbuff members around, and the netfilter tree adjusted the ifdef guards for the bridging info pointer. Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29tcp: change TCP_ECN prefixes to lower caseFlorian Westphal
Suggested by Stephen. Also drop inline keyword and let compiler decide. gcc 4.7.3 decides to no longer inline tcp_ecn_check_ce, so split it up. The actual evaluation is not inlined anymore while the ECN_OK test is. Suggested-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29tcp: move TCP_ECN_create_request out of headerFlorian Westphal
After Octavian Purdilas tcp ipv4/ipv6 unification work this helper only has a single callsite. While at it, convert name to lowercase, suggested by Stephen. Suggested-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29tcp: remove unnecessary assignment.Li RongQing
This variable i is overwritten to 0 by following code Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29net: tcp: add DCTCP congestion control algorithmDaniel Borkmann
This work adds the DataCenter TCP (DCTCP) congestion control algorithm [1], which has been first published at SIGCOMM 2010 [2], resp. follow-up analysis at SIGMETRICS 2011 [3] (and also, more recently as an informational IETF draft available at [4]). DCTCP is an enhancement to the TCP congestion control algorithm for data center networks. Typical data center workloads are i.e. i) partition/aggregate (queries; bursty, delay sensitive), ii) short messages e.g. 50KB-1MB (for coordination and control state; delay sensitive), and iii) large flows e.g. 1MB-100MB (data update; throughput sensitive). DCTCP has therefore been designed for such environments to provide/achieve the following three requirements: * High burst tolerance (incast due to partition/aggregate) * Low latency (short flows, queries) * High throughput (continuous data updates, large file transfers) with commodity, shallow buffered switches The basic idea of its design consists of two fundamentals: i) on the switch side, packets are being marked when its internal queue length > threshold K (K is chosen so that a large enough headroom for marked traffic is still available in the switch queue); ii) the sender/host side maintains a moving average of the fraction of marked packets, so each RTT, F is being updated as follows: F := X / Y, where X is # of marked ACKs, Y is total # of ACKs alpha := (1 - g) * alpha + g * F, where g is a smoothing constant The resulting alpha (iow: probability that switch queue is congested) is then being used in order to adaptively decrease the congestion window W: W := (1 - (alpha / 2)) * W The means for receiving marked packets resp. marking them on switch side in DCTCP is the use of ECN. RFC3168 describes a mechanism for using Explicit Congestion Notification from the switch for early detection of congestion, rather than waiting for segment loss to occur. However, this method only detects the presence of congestion, not the *extent*. In the presence of mild congestion, it reduces the TCP congestion window too aggressively and unnecessarily affects the throughput of long flows [4]. DCTCP, as mentioned, enhances Explicit Congestion Notification (ECN) processing to estimate the fraction of bytes that encounter congestion, rather than simply detecting that some congestion has occurred. DCTCP then scales the TCP congestion window based on this estimate [4], thus it can derive multibit feedback from the information present in the single-bit sequence of marks in its control law. And thus act in *proportion* to the extent of congestion, not its *presence*. Switches therefore set the Congestion Experienced (CE) codepoint in packets when internal queue lengths exceed threshold K. Resulting, DCTCP delivers the same or better throughput than normal TCP, while using 90% less buffer space. It was found in [2] that DCTCP enables the applications to handle 10x the current background traffic, without impacting foreground traffic. Moreover, a 10x increase in foreground traffic did not cause any timeouts, and thus largely eliminates TCP incast collapse problems. The algorithm itself has already seen deployments in large production data centers since then. We did a long-term stress-test and analysis in a data center, short summary of our TCP incast tests with iperf compared to cubic: This test measured DCTCP throughput and latency and compared it with CUBIC throughput and latency for an incast scenario. In this test, 19 senders sent at maximum rate to a single receiver. The receiver simply ran iperf -s. The senders ran iperf -c <receiver> -t 30. All senders started simultaneously (using local clocks synchronized by ntp). This test was repeated multiple times. Below shows the results from a single test. Other tests are similar. (DCTCP results were extremely consistent, CUBIC results show some variance induced by the TCP timeouts that CUBIC encountered.) For this test, we report statistics on the number of TCP timeouts, flow throughput, and traffic latency. 1) Timeouts (total over all flows, and per flow summaries): CUBIC DCTCP Total 3227 25 Mean 169.842 1.316 Median 183 1 Max 207 5 Min 123 0 Stddev 28.991 1.600 Timeout data is taken by measuring the net change in netstat -s "other TCP timeouts" reported. As a result, the timeout measurements above are not restricted to the test traffic, and we believe that it is likely that all of the "DCTCP timeouts" are actually timeouts for non-test traffic. We report them nevertheless. CUBIC will also include some non-test timeouts, but they are drawfed by bona fide test traffic timeouts for CUBIC. Clearly DCTCP does an excellent job of preventing TCP timeouts. DCTCP reduces timeouts by at least two orders of magnitude and may well have eliminated them in this scenario. 2) Throughput (per flow in Mbps): CUBIC DCTCP Mean 521.684 521.895 Median 464 523 Max 776 527 Min 403 519 Stddev 105.891 2.601 Fairness 0.962 0.999 Throughput data was simply the average throughput for each flow reported by iperf. By avoiding TCP timeouts, DCTCP is able to achieve much better per-flow results. In CUBIC, many flows experience TCP timeouts which makes flow throughput unpredictable and unfair. DCTCP, on the other hand, provides very clean predictable throughput without incurring TCP timeouts. Thus, the standard deviation of CUBIC throughput is dramatically higher than the standard deviation of DCTCP throughput. Mean throughput is nearly identical because even though cubic flows suffer TCP timeouts, other flows will step in and fill the unused bandwidth. Note that this test is something of a best case scenario for incast under CUBIC: it allows other flows to fill in for flows experiencing a timeout. Under situations where the receiver is issuing requests and then waiting for all flows to complete, flows cannot fill in for timed out flows and throughput will drop dramatically. 3) Latency (in ms): CUBIC DCTCP Mean 4.0088 0.04219 Median 4.055 0.0395 Max 4.2 0.085 Min 3.32 0.028 Stddev 0.1666 0.01064 Latency for each protocol was computed by running "ping -i 0.2 <receiver>" from a single sender to the receiver during the incast test. For DCTCP, "ping -Q 0x6 -i 0.2 <receiver>" was used to ensure that traffic traversed the DCTCP queue and was not dropped when the queue size was greater than the marking threshold. The summary statistics above are over all ping metrics measured between the single sender, receiver pair. The latency results for this test show a dramatic difference between CUBIC and DCTCP. CUBIC intentionally overflows the switch buffer which incurs the maximum queue latency (more buffer memory will lead to high latency.) DCTCP, on the other hand, deliberately attempts to keep queue occupancy low. The result is a two orders of magnitude reduction of latency with DCTCP - even with a switch with relatively little RAM. Switches with larger amounts of RAM will incur increasing amounts of latency for CUBIC, but not for DCTCP. 4) Convergence and stability test: This test measured the time that DCTCP took to fairly redistribute bandwidth when a new flow commences. It also measured DCTCP's ability to remain stable at a fair bandwidth distribution. DCTCP is compared with CUBIC for this test. At the commencement of this test, a single flow is sending at maximum rate (near 10 Gbps) to a single receiver. One second after that first flow commences, a new flow from a distinct server begins sending to the same receiver as the first flow. After the second flow has sent data for 10 seconds, the second flow is terminated. The first flow sends for an additional second. Ideally, the bandwidth would be evenly shared as soon as the second flow starts, and recover as soon as it stops. The results of this test are shown below. Note that the flow bandwidth for the two flows was measured near the same time, but not simultaneously. DCTCP performs nearly perfectly within the measurement limitations of this test: bandwidth is quickly distributed fairly between the two flows, remains stable throughout the duration of the test, and recovers quickly. CUBIC, in contrast, is slow to divide the bandwidth fairly, and has trouble remaining stable. CUBIC DCTCP Seconds Flow 1 Flow 2 Seconds Flow 1 Flow 2 0 9.93 0 0 9.92 0 0.5 9.87 0 0.5 9.86 0 1 8.73 2.25 1 6.46 4.88 1.5 7.29 2.8 1.5 4.9 4.99 2 6.96 3.1 2 4.92 4.94 2.5 6.67 3.34 2.5 4.93 5 3 6.39 3.57 3 4.92 4.99 3.5 6.24 3.75 3.5 4.94 4.74 4 6 3.94 4 5.34 4.71 4.5 5.88 4.09 4.5 4.99 4.97 5 5.27 4.98 5 4.83 5.01 5.5 4.93 5.04 5.5 4.89 4.99 6 4.9 4.99 6 4.92 5.04 6.5 4.93 5.1 6.5 4.91 4.97 7 4.28 5.8 7 4.97 4.97 7.5 4.62 4.91 7.5 4.99 4.82 8 5.05 4.45 8 5.16 4.76 8.5 5.93 4.09 8.5 4.94 4.98 9 5.73 4.2 9 4.92 5.02 9.5 5.62 4.32 9.5 4.87 5.03 10 6.12 3.2 10 4.91 5.01 10.5 6.91 3.11 10.5 4.87 5.04 11 8.48 0 11 8.49 4.94 11.5 9.87 0 11.5 9.9 0 SYN/ACK ECT test: This test demonstrates the importance of ECT on SYN and SYN-ACK packets by measuring the connection probability in the presence of competing flows for a DCTCP connection attempt *without* ECT in the SYN packet. The test was repeated five times for each number of competing flows. Competing Flows 1 | 2 | 4 | 8 | 16 ------------------------------ Mean Connection Probability 1 | 0.67 | 0.45 | 0.28 | 0 Median Connection Probability 1 | 0.65 | 0.45 | 0.25 | 0 As the number of competing flows moves beyond 1, the connection probability drops rapidly. Enabling DCTCP with this patch requires the following steps: DCTCP must be running both on the sender and receiver side in your data center, i.e.: sysctl -w net.ipv4.tcp_congestion_control=dctcp Also, ECN functionality must be enabled on all switches in your data center for DCTCP to work. The default ECN marking threshold (K) heuristic on the switch for DCTCP is e.g., 20 packets (30KB) at 1Gbps, and 65 packets (~100KB) at 10Gbps (K > 1/7 * C * RTT, [4]). In above tests, for each switch port, traffic was segregated into two queues. For any packet with a DSCP of 0x01 - or equivalently a TOS of 0x04 - the packet was placed into the DCTCP queue. All other packets were placed into the default drop-tail queue. For the DCTCP queue, RED/ECN marking was enabled, here, with a marking threshold of 75 KB. More details however, we refer you to the paper [2] under section 3). There are no code changes required to applications running in user space. DCTCP has been implemented in full *isolation* of the rest of the TCP code as its own congestion control module, so that it can run without a need to expose code to the core of the TCP stack, and thus nothing changes for non-DCTCP users. Changes in the CA framework code are minimal, and DCTCP algorithm operates on mechanisms that are already available in most Silicon. The gain (dctcp_shift_g) is currently a fixed constant (1/16) from the paper, but we leave the option that it can be chosen carefully to a different value by the user. In case DCTCP is being used and ECN support on peer site is off, DCTCP falls back after 3WHS to operate in normal TCP Reno mode. ss {-4,-6} -t -i diag interface: ... dctcp wscale:7,7 rto:203 rtt:2.349/0.026 mss:1448 cwnd:2054 ssthresh:1102 ce_state 0 alpha 15 ab_ecn 0 ab_tot 735584 send 10129.2Mbps pacing_rate 20254.1Mbps unacked:1822 retrans:0/15 reordering:101 rcv_space:29200 ... dctcp-reno wscale:7,7 rto:201 rtt:0.711/1.327 ato:40 mss:1448 cwnd:10 ssthresh:1102 fallback_mode send 162.9Mbps pacing_rate 325.5Mbps rcv_rtt:1.5 rcv_space:29200 More information about DCTCP can be found in [1-4]. [1] http://simula.stanford.edu/~alizade/Site/DCTCP.html [2] http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf [3] http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp_analysis-full.pdf [4] http://tools.ietf.org/html/draft-bensley-tcpm-dctcp-00 Joint work with Florian Westphal and Glenn Judd. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29net: tcp: more detailed ACK events and events for CE marked packetsFlorian Westphal
DataCenter TCP (DCTCP) determines cwnd growth based on ECN information and ACK properties, e.g. ACK that updates window is treated differently than DUPACK. Also DCTCP needs information whether ACK was delayed ACK. Furthermore, DCTCP also implements a CE state machine that keeps track of CE markings of incoming packets. Therefore, extend the congestion control framework to provide these event types, so that DCTCP can be properly implemented as a normal congestion algorithm module outside of the core stack. Joint work with Daniel Borkmann and Glenn Judd. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29net: tcp: split ack slow/fast events from cwnd_eventFlorian Westphal
The congestion control ops "cwnd_event" currently supports CA_EVENT_FAST_ACK and CA_EVENT_SLOW_ACK events (among others). Both FAST and SLOW_ACK are only used by Westwood congestion control algorithm. This removes both flags from cwnd_event and adds a new in_ack_event callback for this. The goal is to be able to provide more detailed information about ACKs, such as whether ECE flag was set, or whether the ACK resulted in a window update. It is required for DataCenter TCP (DCTCP) congestion control algorithm as it makes a different choice depending on ECE being set or not. Joint work with Daniel Borkmann and Glenn Judd. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29net: tcp: add flag for ca to indicate that ECN is requiredDaniel Borkmann
This patch adds a flag to TCP congestion algorithms that allows for requesting to mark IPv4/IPv6 sockets with transport as ECN capable, that is, ECT(0), when required by a congestion algorithm. It is currently used and needed in DataCenter TCP (DCTCP), as it requires both peers to assert ECT on all IP packets sent - it uses ECN feedback (i.e. CE, Congestion Encountered information) from switches inside the data center to derive feedback to the end hosts. Therefore, simply add a new flag to icsk_ca_ops. Note that DCTCP's algorithm/behaviour slightly diverges from RFC3168, therefore this is only (!) enabled iff the assigned congestion control ops module has requested this. By that, we can tightly couple this logic really only to the provided congestion control ops. Joint work with Florian Westphal and Glenn Judd. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>