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2017-08-06tcp: fix cwnd undo in Reno and HTCP congestion controlsYuchung Cheng4-4/+4
Using ssthresh to revert cwnd is less reliable when ssthresh is bounded to 2 packets. This patch uses an existing variable in TCP "prior_cwnd" that snapshots the cwnd right before entering fast recovery and RTO recovery in Reno. This fixes the issue discussed in netdev thread: "A buggy behavior for Linux TCP Reno and HTCP" https://www.spinics.net/lists/netdev/msg444955.html Suggested-by: Neal Cardwell <ncardwell@google.com> Reported-by: Wei Sun <unlcsewsun@gmail.com> Signed-off-by: Yuchung Cheng <ncardwell@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06net: systemport: Support 64bit statisticskiki good2-17/+82
When using Broadcom Systemport device in 32bit Platform, ifconfig can only report up to 4G tx,rx status, which will be wrapped to 0 when the number of incoming or outgoing packets exceeds 4G, only taking around 2 hours in busy network environment (such as streaming). Therefore, it makes hard for network diagnostic tool to get reliable statistical result, so the patch is used to add 64bit support for Broadcom Systemport device in 32bit Platform. This patch provides 64bit statistics capability on both ethtool and ifconfig. Signed-off-by: Jianming.qiao <kiki-good@hotmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06liquidio: moved console_bitmask module param to lio_main.cIntiyaz Basha3-14/+17
Moving PF module param console_bitmask to lio_main.c for consistency. Signed-off-by: Intiyaz Basha <intiyaz.basha@cavium.com> Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06liquidio: add missing strings in oct_dev_state_str arrayIntiyaz Basha1-2/+3
There's supposed to be a one-to-one correspondence between the 18 macros that #define the OCT_DEV states (in octeon_device.h) and the strings in the oct_dev_state_str array, but there are only 14 strings in the array. Add the missing strings (so they become 18 in total), and also revise some incorrect/outdated text of existing strings. Signed-off-by: Intiyaz Basha <intiyaz.basha@cavium.com> Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06sfp: add SFP module supportRussell King3-0/+921
Add support for SFP hotpluggable modules via sfp-bus and phylink. This supports both copper and optical SFP modules, which require different Serdes modes in order to properly negotiate the link. Optical SFP modules typically require the Serdes link to be talking 1000BaseX mode - this is the gigabit ethernet mode defined by the 802.3 standard. Copper SFP modules typically integrate a PHY in the module to convert from Serdes to copper, and the PHY will be configured by the vendor to either present a 1000BaseX Serdes link (for fixed 1000BaseT) or a SGMII Serdes link. However, this is vendor defined, so we instead detect the PHY, switch the link to SGMII mode, and use traditional PHY based negotiation. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06phylink: add in-band autonegotiation support for 10GBase-KR mode.Russell King1-0/+17
Add in-band autonegotation support for 10GBase-KR mode. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06phylink: add support for MII ioctl access to Clause 45 PHYsRussell King1-33/+124
Add support for reading and writing the clause 45 MII registers. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06phylink: add module EEPROM supportRussell King2-0/+31
Add support for reading module EEPROMs through phylink. Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06sfp: add sfp-bus to bridge between network devices and sfp cagesRussell King5-0/+1097
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06phylink: add phylink infrastructureRussell King6-0/+1328
The link between the ethernet MAC and its PHY has become more complex as the interface evolves. This is especially true with serdes links, where the part of the PHY is effectively integrated into the MAC. Serdes links can be connected to a variety of devices, including SFF modules soldered down onto the board with the MAC, a SFP cage with a hotpluggable SFP module which may contain a PHY or directly modulate the serdes signals onto optical media with or without a PHY, or even a classical PHY connection. Moreover, the negotiation information on serdes links comes in two varieties - SGMII mode, where the PHY provides its speed/duplex/flow control information to the MAC, and 1000base-X mode where both ends exchange their abilities and each resolve the link capabilities. This means we need a more flexible means to support these arrangements, particularly with the hotpluggable nature of SFP, where the PHY can be attached or detached after the network device has been brought up. Ethtool information can come from multiple sources: - we may have a PHY operating in either SGMII or 1000base-X mode, in which case we take ethtool/mii data directly from the PHY. - we may have a optical SFP module without a PHY, with the MAC operating in 1000base-X mode - the ethtool/mii data needs to come from the MAC. - we may have a copper SFP module with a PHY whic can't be accessed, which means we need to take ethtool/mii data from the MAC. Phylink aims to solve this by providing an intermediary between the MAC and PHY, providing a safe way for PHYs to be hotplugged, and allowing a SFP driver to reconfigure the serdes connection. Phylink also takes over support of fixed link connections, where the speed/duplex/flow control are fixed, but link status may be controlled by a GPIO signal. By avoiding the fixed-phy implementation, phylink can provide a faster response to link events: fixed-phy has to wait for phylib to operate its state machine, which can take several seconds. In comparison, phylink takes milliseconds. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> - remove sync status - rework supported and advertisment handling - add 1000base-x speed for fixed links - use functionality exported from phy-core, reworking __phylink_ethtool_ksettings_set for it Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06net: phy: add I2C mdio busRussell King4-0/+139
Add an I2C MDIO bus bridge library, to allow phylib to access PHYs which are connected to an I2C bus instead of the more conventional MDIO bus. Such PHYs can be found in SFP adapters and SFF modules. Since PHYs appear at I2C bus address 0x40..0x5f, and 0x50/0x51 are reserved for SFP EEPROMs/diagnostics, we must not allow the MDIO bus to access these I2C addresses. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06net: phy: export phy_start_machine() for phylinkRussell King1-0/+1
phylink will need phy_start_machine exported, so lets export it as a GPL symbol. Documentation/networking/phy.txt indicates that this should be a PHY API function. Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06net: phy: provide a hook for link up/link down eventsRussell King3-22/+35
Sometimes, we need to do additional work between the PHY coming up and marking the carrier present - for example, we may need to wait for the PHY to MAC link to finish negotiation. This changes phylib to provide a notification function pointer which avoids the built-in netif_carrier_on() and netif_carrier_off() functions. Standard ->adjust_link functionality is provided by hooking a helper into the new ->phy_link_change method. Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06net: phy: add 1000Base-X to phy settings tableRussell King1-0/+5
Add the missing 1000Base-X entry to the phy settings table. This was not included because the original code could not cope with more than 32 bits of link mode mask. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06net: phy: move phy_lookup_setting() and guts of phy_supported_speeds() to phy-coreRussell King3-129/+142
phy_lookup_setting() provides useful functionality in ethtool code outside phylib. Move it to phy-core and allow it to be re-used (eg, in phylink) rather than duplicated elsewhere. Note that this supports the larger linkmode space. As we move the phy settings table, we also need to move the guts of phy_supported_speeds() as well. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06net: phy: split out PHY speed and duplex string generationRussell King3-37/+53
Other code would like to make use of this, so make the speed and duplex string generation visible, and place it in a separate file. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06net: phy: allow settings table to support more than 32 link modesRussell King1-18/+26
Allow the phy settings table to support more than 32 link modes by switching to the ethtool link mode bit number representation, rather than storing the mask. This will allow phylink and other ethtool code to share the settings table to look up settings. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06udp: no need to preserve skb->dstPaolo Abeni1-8/+5
__ip_options_echo() does not need anymore skb->dst, so we can avoid explicitly preserving it for its own sake. This is almost a revert of commit 0ddf3fb2c43d ("udp: preserve skb->dst if required for IP options processing") plus some lifting to fit later changes. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06Revert "ipv4: keep skb->dst around in presence of IP options"Paolo Abeni1-8/+1
ip_options_echo() does not use anymore the skb->dst and don't need to keep the dst around for options's sake only. This reverts commit 34b2cef20f19c87999fff3da4071e66937db9644. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06ip/options: explicitly provide net ns to __ip_options_echo()Paolo Abeni8-17/+20
__ip_options_echo() uses the current network namespace, and currently retrives it via skb->dst->dev. This commit adds an explicit 'net' argument to __ip_options_echo() and update all the call sites to provide it, usually via a simpler sock_net(). After this change, __ip_options_echo() no more needs to access skb->dst and we can drop a couple of hack to preserve such info in the rx path. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06IP: do not modify ingress packet IP option in ip_options_echo()Paolo Abeni1-3/+0
While computing the response option set for LSRR, ip_options_echo() also changes the ingress packet LSRR addresses list, setting the last one to the dst specific address for the ingress packet - via memset(start[ ... The only visible effect of such change - beyond possibly damaging shared/cloned skbs - is modifying the data carried by ICMP replies changing the header information for reported the ingress packet, which violates RFC1122 3.2.2.6. All the others call sites just ignore the ingress packet IP options after calling ip_options_echo() Note that the last element in the LSRR option address list for the reply packet will be properly set later in the ip output path via ip_options_build(). This buggy memset() predates git history and apparently was present into the initial ip_options_echo() implementation in linux 1.3.30 but still looks wrong. The removal of the fib_compute_spec_dst() call will help completely dropping the skb->dst usage by __ip_options_echo() with a later patch. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04aquantia: Switch to use napi_gro_receivePavel Belous3-3/+10
Add support for GRO (generic receive offload) for aQuantia Atlantic driver. This results in a perfomance improvement when GRO is enabled. Signed-off-by: Pavel Belous <pavel.belous@aquantia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: comment fixes against BPF devmap helper callsJohn Fastabend1-5/+11
Update BPF comments to accurately reflect XDP usage. Fixes: 97f91a7cf04ff ("bpf: add bpf_redirect_map helper routine") Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: avoid atomic swap in tcf_exts_changeJiri Pirko4-15/+8
tcf_exts_change is always called on newly created exts, which are not used on fastpath. Therefore, simple struct copy is enough. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: cls_u32: no need to call tcf_exts_change for newly allocated structJiri Pirko1-14/+4
As the n struct was allocated right before u32_set_parms call, no need to use tcf_exts_change to do atomic change, and we can just fill-up the unused exts struct directly by tcf_exts_validate. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: cls_route: no need to call tcf_exts_change for newly allocated structJiri Pirko1-21/+9
As the f struct was allocated right before route4_set_parms call, no need to use tcf_exts_change to do atomic change, and we can just fill-up the unused exts struct directly by tcf_exts_validate. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: cls_flow: no need to call tcf_exts_change for newly allocated structJiri Pirko1-25/+16
As the fnew struct just was allocated, so no need to use tcf_exts_change to do atomic change, and we can just fill-up the unused exts struct directly by tcf_exts_validate. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: cls_cgroup: no need to call tcf_exts_change for newly allocated structJiri Pirko1-12/+2
As the new struct just was allocated, so no need to use tcf_exts_change to do atomic change, and we can just fill-up the unused exts struct directly by tcf_exts_validate. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: cls_bpf: no need to call tcf_exts_change for newly allocated structJiri Pirko1-19/+6
As the prog struct was allocated right before cls_bpf_set_parms call, no need to use tcf_exts_change to do atomic change, and we can just fill-up the unused exts struct directly by tcf_exts_validate. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: cls_basic: no need to call tcf_exts_change for newly allocated structJiri Pirko1-11/+2
As the f struct was allocated right before basic_set_parms call, no need to use tcf_exts_change to do atomic change, and we can just fill-up the unused exts struct directly by tcf_exts_validate. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: cls_matchall: no need to call tcf_exts_change for newly allocated structJiri Pirko1-12/+2
As the head struct was allocated right before mall_set_parms call, no need to use tcf_exts_change to do atomic change, and we can just fill-up the unused exts struct directly by tcf_exts_validate. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: cls_fw: no need to call tcf_exts_change for newly allocated structJiri Pirko1-16/+5
As the f struct was allocated right before fw_set_parms call, no need to use tcf_exts_change to do atomic change, and we can just fill-up the unused exts struct directly by tcf_exts_validate. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: cls_flower: no need to call tcf_exts_change for newly allocated structJiri Pirko1-11/+2
As the f struct was allocated right before fl_set_parms call, no need to use tcf_exts_change to do atomic change, and we can just fill-up the unused exts struct directly by tcf_exts_validate. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: cls_fw: rename fw_change_attrs functionJiri Pirko1-6/+5
Since the function name is misleading since it is not changing anything, name it similarly to other cls. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: cls_bpf: rename cls_bpf_modify_existing functionJiri Pirko1-6/+4
The name cls_bpf_modify_existing is highly misleading, as it indeed does not modify anything existing. It does not modify at all. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: use tcf_exts_has_actions instead of exts->nr_actionsJiri Pirko1-1/+1
For check in tcf_exts_dump use tcf_exts_has_actions helper instead of exts->nr_actions for checking if there are any actions present. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: remove check for number of actions in tcf_exts_execJiri Pirko2-4/+3
Leave it to tcf_action_exec to return TC_ACT_OK in case there is no action present. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: fix return value of tcf_exts_execJiri Pirko1-2/+2
Return the defined TC_ACT_OK instead of 0. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: remove redundant helpers tcf_exts_is_predicative and tcf_exts_is_availableJiri Pirko4-33/+3
These two helpers are doing the same as tcf_exts_has_actions, so remove them and use tcf_exts_has_actions instead. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: use tcf_exts_has_actions in tcf_exts_execJiri Pirko1-23/+23
Use the tcf_exts_has_actions helper instead or directly testing exts->nr_actions in tcf_exts_exec. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: change names of action number helpers to be aligned with the restJiri Pirko9-19/+37
The rest of the helpers are named tcf_exts_*, so change the name of the action number helpers to be aligned. While at it, change to inline functions. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: remove unneeded tcf_em_tree_changeJiri Pirko4-34/+7
Since tcf_em_tree_validate could be always called on a newly created filter, there is no need for this change function. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: sch_atm: use Qdisc_class_common structureJiri Pirko1-6/+6
Even if it is only for classid now, use this common struct a be aligned with the rest of the classful qdiscs. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: hns: Fix for __udivdi3 compiler errorLin Yun Sheng1-1/+2
This patch fixes the __udivdi3 undefined error reported by test robot. Fixes: b8c17f708831 ("net: hns: Add self-adaptive interrupt coalesce support in hns driver") Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: phy: marvell: logical vs bitwise OR typoDan Carpenter1-1/+1
This was supposed to be a bitwise OR but there is a || vs | typo. Fixes: 864dc729d528 ("net: phy: marvell: Refactor m88e1121 RGMII delay configuration") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03test: add msg_zerocopy testWillem de Bruijn4-1/+811
Introduce regression test for msg_zerocopy feature. Send traffic from one process to another with and without zerocopy. Evaluate tcp, udp, raw and packet sockets, including variants - udp: corking and corking with mixed copy/zerocopy calls - raw: with and without hdrincl - packet: at both raw and dgram level Test on both ipv4 and ipv6, optionally with ethtool changes to disable scatter-gather, tx checksum or tso offload. All of these can affect zerocopy behavior. The regression test can be run on a single machine if over a veth pair. Then skb_orphan_frags_rx must be modified to be identical to skb_orphan_frags to allow forwarding zerocopy locally. The msg_zerocopy.sh script will setup the veth pair in network namespaces and run all tests. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03tcp: enable MSG_ZEROCOPYWillem de Bruijn1-1/+31
Enable support for MSG_ZEROCOPY to the TCP stack. TSO and GSO are both supported. Only data sent to remote destinations is sent without copying. Packets looped onto a local destination have their payload copied to avoid unbounded latency. Tested: A 10x TCP_STREAM between two hosts showed a reduction in netserver process cycles by up to 70%, depending on packet size. Systemwide, savings are of course much less pronounced, at up to 20% best case. msg_zerocopy.sh 4 tcp: without zerocopy tx=121792 (7600 MB) txc=0 zc=n rx=60458 (7600 MB) with zerocopy tx=286257 (17863 MB) txc=286257 zc=y rx=140022 (17863 MB) This test opens a pair of sockets over veth, one one calls send with 64KB and optionally MSG_ZEROCOPY and on the other reads the initial bytes. The receiver truncates, so this is strictly an upper bound on what is achievable. It is more representative of sending data out of a physical NIC (when payload is not touched, either). Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03sock: ulimit on MSG_ZEROCOPY pagesWillem de Bruijn3-1/+55
Bound the number of pages that a user may pin. Follow the lead of perf tools to maintain a per-user bound on memory locked pages commit 789f90fcf6b0 ("perf_counter: per user mlock gift") Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03sock: MSG_ZEROCOPY notification coalescingWillem de Bruijn2-10/+106
In the simple case, each sendmsg() call generates data and eventually a zerocopy ready notification N, where N indicates the Nth successful invocation of sendmsg() with the MSG_ZEROCOPY flag on this socket. TCP and corked sockets can cause send() calls to append new data to an existing sk_buff and, thus, ubuf_info. In that case the notification must hold a range. odify ubuf_info to store a inclusive range [N..N+m] and add skb_zerocopy_realloc() to optionally extend an existing range. Also coalesce notifications in this common case: if a notification [1, 1] is about to be queued while [0, 0] is the queue tail, just modify the head of the queue to read [0, 1]. Coalescing is limited to a few TSO frames worth of data to bound notification latency. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03sock: enable MSG_ZEROCOPYWillem de Bruijn5-33/+36
Prepare the datapath for refcounted ubuf_info. Clone ubuf_info with skb_zerocopy_clone() wherever needed due to skb split, merge, resize or clone. Split skb_orphan_frags into two variants. The split, merge, .. paths support reference counted zerocopy buffers, so do not do a deep copy. Add skb_orphan_frags_rx for paths that may loop packets to receive sockets. That is not allowed, as it may cause unbounded latency. Deep copy all zerocopy copy buffers, ref-counted or not, in this path. The exact locations to modify were chosen by exhaustively searching through all code that might modify skb_frag references and/or the the SKBTX_DEV_ZEROCOPY tx_flags bit. The changes err on the safe side, in two ways. (1) legacy ubuf_info paths virtio and tap are not modified. They keep a 1:1 ubuf_info to sk_buff relationship. Calls to skb_orphan_frags still call skb_copy_ubufs and thus copy frags in this case. (2) not all copies deep in the stack are addressed yet. skb_shift, skb_split and skb_try_coalesce can be refined to avoid copying. These are not in the hot path and this patch is hairy enough as is, so that is left for future refinement. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>