- 16 2月, 2013 1 次提交
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由 Pravin B Shelar 提交于
Following patch adds GRE protocol offload handler so that skb_gso_segment() can segment GRE packets. SKB GSO CB is added to keep track of total header length so that skb_segment can push entire header. e.g. in case of GRE, skb_segment need to push inner and outer headers to every segment. New NETIF_F_GRE_GSO feature is added for devices which support HW GRE TSO offload. Currently none of devices support it therefore GRE GSO always fall backs to software GSO. [ Compute pkt_len before ip_local_out() invocation. -DaveM ] Signed-off-by: NPravin B Shelar <pshelar@nicira.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 14 2月, 2013 3 次提交
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由 Pravin B Shelar 提交于
Patch cef401de (net: fix possible wrong checksum generation) fixed wrong checksum calculation but it broke TSO by defining new GSO type but not a netdev feature for that type. net_gso_ok() would not allow hardware checksum/segmentation offload of such packets without the feature. Following patch fixes TSO and wrong checksum. This patch uses same logic that Eric Dumazet used. Patch introduces new flag SKBTX_SHARED_FRAG if at least one frag can be modified by the user. but SKBTX_SHARED_FRAG flag is kept in skb shared info tx_flags rather than gso_type. tx_flags is better compared to gso_type since we can have skb with shared frag without gso packet. It does not link SHARED_FRAG to GSO, So there is no need to define netdev feature for this. Signed-off-by: NPravin B Shelar <pshelar@nicira.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Andrey Vagin 提交于
A timestamp can be set, only if a socket is in the repair mode. This patch adds a new socket option TCP_TIMESTAMP, which allows to get and set current tcp times stamp. Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: James Morris <jmorris@namei.org> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Patrick McHardy <kaber@trash.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: NAndrey Vagin <avagin@openvz.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Andrey Vagin 提交于
This functionality is used for restoring tcp sockets. A tcp timestamp depends on how long a system has been running, so it's differ for each host. The solution is to set a per-socket offset. A per-socket offset for a TIME_WAIT socket is inherited from a proper tcp socket. tcp_request_sock doesn't have a timestamp offset, because the repair mode for them are not implemented. Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: James Morris <jmorris@namei.org> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Patrick McHardy <kaber@trash.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: NAndrey Vagin <avagin@openvz.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 06 2月, 2013 1 次提交
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由 Stephen Hemminger 提交于
TCP Appropriate Byte Count was added by me, but later disabled. There is no point in maintaining it since it is a potential source of bugs and Linux already implements other better window protection heuristics. Signed-off-by: NStephen Hemminger <stephen@networkplumber.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 28 1月, 2013 1 次提交
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由 Eric Dumazet 提交于
Pravin Shelar mentioned that GSO could potentially generate wrong TX checksum if skb has fragments that are overwritten by the user between the checksum computation and transmit. He suggested to linearize skbs but this extra copy can be avoided for normal tcp skbs cooked by tcp_sendmsg(). This patch introduces a new SKB_GSO_SHARED_FRAG flag, set in skb_shinfo(skb)->gso_type if at least one frag can be modified by the user. Typical sources of such possible overwrites are {vm}splice(), sendfile(), and macvtap/tun/virtio_net drivers. Tested: $ netperf -H 7.7.8.84 MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 7.7.8.84 () port 0 AF_INET Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.00 3959.52 $ netperf -H 7.7.8.84 -t TCP_SENDFILE TCP SENDFILE TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 7.7.8.84 () port 0 AF_INET Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.00 3216.80 Performance of the SENDFILE is impacted by the extra allocation and copy, and because we use order-0 pages, while the TCP_STREAM uses bigger pages. Reported-by: NPravin Shelar <pshelar@nicira.com> Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 23 1月, 2013 1 次提交
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由 YOSHIFUJI Hideaki / 吉藤英明 提交于
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 11 1月, 2013 2 次提交
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由 Eric Dumazet 提交于
Under unusual circumstances, TCP collapse can split a big GRO TCP packet while its being used in a splice(socket->pipe) operation. skb_splice_bits() releases the socket lock before calling splice_to_pipe(). [ 1081.353685] WARNING: at net/ipv4/tcp.c:1330 tcp_cleanup_rbuf+0x4d/0xfc() [ 1081.371956] Hardware name: System x3690 X5 -[7148Z68]- [ 1081.391820] cleanup rbuf bug: copied AD3BCF1 seq AD370AF rcvnxt AD3CF13 To fix this problem, we must eat skbs in tcp_recv_skb(). Remove the inline keyword from tcp_recv_skb() definition since it has three call sites. Reported-by: NChristian Becker <c.becker@traviangames.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: NEric Dumazet <edumazet@google.com> Tested-by: NWilly Tarreau <w@1wt.eu> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Eric Dumazet 提交于
commit 02275a2e (tcp: don't abort splice() after small transfers) added a regression. [ 83.843570] INFO: rcu_sched self-detected stall on CPU [ 83.844575] INFO: rcu_sched detected stalls on CPUs/tasks: { 6} (detected by 0, t=21002 jiffies, g=4457, c=4456, q=13132) [ 83.844582] Task dump for CPU 6: [ 83.844584] netperf R running task 0 8966 8952 0x0000000c [ 83.844587] 0000000000000000 0000000000000006 0000000000006c6c 0000000000000000 [ 83.844589] 000000000000006c 0000000000000096 ffffffff819ce2bc ffffffffffffff10 [ 83.844592] ffffffff81088679 0000000000000010 0000000000000246 ffff880c4b9ddcd8 [ 83.844594] Call Trace: [ 83.844596] [<ffffffff81088679>] ? vprintk_emit+0x1c9/0x4c0 [ 83.844601] [<ffffffff815ad449>] ? schedule+0x29/0x70 [ 83.844606] [<ffffffff81537bd2>] ? tcp_splice_data_recv+0x42/0x50 [ 83.844610] [<ffffffff8153beaa>] ? tcp_read_sock+0xda/0x260 [ 83.844613] [<ffffffff81537b90>] ? tcp_prequeue_process+0xb0/0xb0 [ 83.844615] [<ffffffff8153c0f0>] ? tcp_splice_read+0xc0/0x250 [ 83.844618] [<ffffffff814dc0c2>] ? sock_splice_read+0x22/0x30 [ 83.844622] [<ffffffff811b820b>] ? do_splice_to+0x7b/0xa0 [ 83.844627] [<ffffffff811ba4bc>] ? sys_splice+0x59c/0x5d0 [ 83.844630] [<ffffffff8119745b>] ? putname+0x2b/0x40 [ 83.844633] [<ffffffff8118bcb4>] ? do_sys_open+0x174/0x1e0 [ 83.844636] [<ffffffff815b6202>] ? system_call_fastpath+0x16/0x1b if recv_actor() returns 0, we should stop immediately, because looping wont give a chance to drain the pipe. Signed-off-by: NEric Dumazet <edumazet@google.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 08 1月, 2013 2 次提交
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Just use dma_async_is_tx_complete() directly. Cc: Vinod Koul <vinod.koul@intel.com> Cc: Tomasz Figa <t.figa@samsung.com> Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com> Signed-off-by: NDan Williams <djbw@fb.com>
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Just use dma_async_issue_pending() directly. Cc: Vinod Koul <vinod.koul@intel.com> Cc: Tomasz Figa <t.figa@samsung.com> Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com> Signed-off-by: NDan Williams <djbw@fb.com>
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- 03 12月, 2012 1 次提交
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由 Willy Tarreau 提交于
TCP coalescing added a regression in splice(socket->pipe) performance, for some workloads because of the way tcp_read_sock() is implemented. The reason for this is the break when (offset + 1 != skb->len). As we released the socket lock, this condition is possible if TCP stack added a fragment to the skb, which can happen with TCP coalescing. So let's go back to the beginning of the loop when this happens, to give a chance to splice more frags per system call. Doing so fixes the issue and makes GRO 10% faster than LRO on CPU-bound splice() workloads instead of the opposite. Signed-off-by: NWilly Tarreau <w@1wt.eu> Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 02 12月, 2012 2 次提交
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由 Eric Dumazet 提交于
Recent network changes allowed high order pages being used for skb fragments. This uncovered a bug in do_tcp_sendpages() which was assuming its caller provided an array of order-0 page pointers. We only have to deal with a single page in this function, and its order is irrelevant. Reported-by: NWilly Tarreau <w@1wt.eu> Tested-by: NWilly Tarreau <w@1wt.eu> Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Eric Dumazet 提交于
As time passed, available memory increased faster than number of concurrent tcp sockets. As a result, a machine with 4GB of ram gets a hash table with 524288 slots, using 8388608 bytes of memory. Lets change that by a 16x factor (one slot for 128 KB of ram) Even if a small machine needs a _lot_ of sockets, tcp lookups are now very efficient, using one cache line per socket. Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 19 11月, 2012 1 次提交
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由 Eric W. Biederman 提交于
Allow an unpriviled user who has created a user namespace, and then created a network namespace to effectively use the new network namespace, by reducing capable(CAP_NET_ADMIN) and capable(CAP_NET_RAW) calls to be ns_capable(net->user_ns, CAP_NET_ADMIN), or capable(net->user_ns, CAP_NET_RAW) calls. Settings that merely control a single network device are allowed. Either the network device is a logical network device where restrictions make no difference or the network device is hardware NIC that has been explicity moved from the initial network namespace. In general policy and network stack state changes are allowed while resource control is left unchanged. Allow creating raw sockets. Allow the SIOCSARP ioctl to control the arp cache. Allow the SIOCSIFFLAG ioctl to allow setting network device flags. Allow the SIOCSIFADDR ioctl to allow setting a netdevice ipv4 address. Allow the SIOCSIFBRDADDR ioctl to allow setting a netdevice ipv4 broadcast address. Allow the SIOCSIFDSTADDR ioctl to allow setting a netdevice ipv4 destination address. Allow the SIOCSIFNETMASK ioctl to allow setting a netdevice ipv4 netmask. Allow the SIOCADDRT and SIOCDELRT ioctls to allow adding and deleting ipv4 routes. Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls for adding, changing and deleting gre tunnels. Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls for adding, changing and deleting ipip tunnels. Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls for adding, changing and deleting ipsec virtual tunnel interfaces. Allow setting the MRT_INIT, MRT_DONE, MRT_ADD_VIF, MRT_DEL_VIF, MRT_ADD_MFC, MRT_DEL_MFC, MRT_ASSERT, MRT_PIM, MRT_TABLE socket options on multicast routing sockets. Allow setting and receiving IPOPT_CIPSO, IP_OPT_SEC, IP_OPT_SID and arbitrary ip options. Allow setting IP_SEC_POLICY/IP_XFRM_POLICY ipv4 socket option. Allow setting the IP_TRANSPARENT ipv4 socket option. Allow setting the TCP_REPAIR socket option. Allow setting the TCP_CONGESTION socket option. Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 16 11月, 2012 1 次提交
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由 Andrew Vagin 提交于
Currently if a socket was repaired with a few packet in a write queue, a kernel bug may be triggered: kernel BUG at net/ipv4/tcp_output.c:2330! RIP: 0010:[<ffffffff8155784f>] tcp_retransmit_skb+0x5ff/0x610 According to the initial realization v3.4-rc2-963-gc0e88ff0, all skb-s should look like already posted. This patch fixes code according with this sentence. Here are three points, which were not done in the initial patch: 1. A tcp send head should not be changed 2. Initialize TSO state of a skb 3. Reset the retransmission time This patch moves logic from tcp_sendmsg to tcp_write_xmit. A packet passes the ussual way, but isn't sent to network. This patch solves all described problems and handles tcp_sendpages. Cc: Pavel Emelyanov <xemul@parallels.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: James Morris <jmorris@namei.org> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Patrick McHardy <kaber@trash.net> Signed-off-by: NAndrey Vagin <avagin@openvz.org> Acked-by: NPavel Emelyanov <xemul@parallels.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 23 10月, 2012 2 次提交
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由 Yuchung Cheng 提交于
Add a bit TCPI_OPT_SYN_DATA (32) to the socket option TCP_INFO:tcpi_options. It's set if the data in SYN (sent or received) is acked by SYN-ACK. Server or client application can use this information to check Fast Open success rate. Signed-off-by: NYuchung Cheng <ycheng@google.com> Acked-by: NNeal Cardwell <ncardwell@google.com> Acked-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Eric Dumazet 提交于
SIOCINQ can use the lock_sock_fast() version to avoid double acquisition of socket lock. Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 19 10月, 2012 1 次提交
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由 Eric Dumazet 提交于
tcp_ioctl() tries to take into account if tcp socket received a FIN to report correct number bytes in receive queue. But its flaky because if the application ate the last skb, we return 1 instead of 0. Correct way to detect that FIN was received is to test SOCK_DONE. Reported-by: NElliot Hughes <enh@google.com> Signed-off-by: NEric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 25 9月, 2012 1 次提交
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由 Eric Dumazet 提交于
We currently use a per socket order-0 page cache for tcp_sendmsg() operations. This page is used to build fragments for skbs. Its done to increase probability of coalescing small write() into single segments in skbs still in write queue (not yet sent) But it wastes a lot of memory for applications handling many mostly idle sockets, since each socket holds one page in sk->sk_sndmsg_page Its also quite inefficient to build TSO 64KB packets, because we need about 16 pages per skb on arches where PAGE_SIZE = 4096, so we hit page allocator more than wanted. This patch adds a per task frag allocator and uses bigger pages, if available. An automatic fallback is done in case of memory pressure. (up to 32768 bytes per frag, thats order-3 pages on x86) This increases TCP stream performance by 20% on loopback device, but also benefits on other network devices, since 8x less frags are mapped on transmit and unmapped on tx completion. Alexander Duyck mentioned a probable performance win on systems with IOMMU enabled. Its possible some SG enabled hardware cant cope with bigger fragments, but their ndo_start_xmit() should already handle this, splitting a fragment in sub fragments, since some arches have PAGE_SIZE=65536 Successfully tested on various ethernet devices. (ixgbe, igb, bnx2x, tg3, mellanox mlx4) Signed-off-by: NEric Dumazet <edumazet@google.com> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Vijay Subramanian <subramanian.vijay@gmail.com> Cc: Alexander Duyck <alexander.h.duyck@intel.com> Tested-by: NVijay Subramanian <subramanian.vijay@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 21 9月, 2012 2 次提交
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由 Andrey Vagin 提交于
rcv_wscale is a symetric parameter with snd_wscale. Both this parameters are set on a connection handshake. Without this value a remote window size can not be interpreted correctly, because a value from a packet should be shifted on rcv_wscale. And one more thing is that wscale_ok should be set too. This patch doesn't break a backward compatibility. If someone uses it in a old scheme, a rcv window will be restored with the same bug (rcv_wscale = 0). v2: Save backward compatibility on big-endian system. Before the first two bytes were snd_wscale and the second two bytes were rcv_wscale. Now snd_wscale is opt_val & 0xFFFF and rcv_wscale >> 16. This approach is independent on byte ordering. Cc: David S. Miller <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: James Morris <jmorris@namei.org> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Patrick McHardy <kaber@trash.net> CC: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: NAndrew Vagin <avagin@openvz.org> Acked-by: NPavel Emelyanov <xemul@parallels.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Christoph Paasch 提交于
Signed-off-by: NChristoph Paasch <christoph.paasch@uclouvain.be> Acked-by: NH.K. Jerry Chu <hkchu@google.com> Acked-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 20 9月, 2012 1 次提交
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由 Michal Kubeček 提交于
If recv() syscall is called for a TCP socket so that - IOAT DMA is used - MSG_WAITALL flag is used - requested length is bigger than sk_rcvbuf - enough data has already arrived to bring rcv_wnd to zero then when tcp_recvmsg() gets to calling sk_wait_data(), receive window can be still zero while sk_async_wait_queue exhausts enough space to keep it zero. As this queue isn't cleaned until the tcp_service_net_dma() call, sk_wait_data() cannot receive any data and blocks forever. If zero receive window and non-empty sk_async_wait_queue is detected before calling sk_wait_data(), process the queue first. Signed-off-by: NMichal Kubecek <mkubecek@suse.cz> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 01 9月, 2012 1 次提交
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由 Jerry Chu 提交于
This patch builds on top of the previous patch to add the support for TFO listeners. This includes - 1. allocating, properly initializing, and managing the per listener fastopen_queue structure when TFO is enabled 2. changes to the inet_csk_accept code to support TFO. E.g., the request_sock can no longer be freed upon accept(), not until 3WHS finishes 3. allowing a TCP_SYN_RECV socket to properly poll() and sendmsg() if it's a TFO socket 4. properly closing a TFO listener, and a TFO socket before 3WHS finishes 5. supporting TCP_FASTOPEN socket option 6. modifying tcp_check_req() to use to check a TFO socket as well as request_sock 7. supporting TCP's TFO cookie option 8. adding a new SYN-ACK retransmit handler to use the timer directly off the TFO socket rather than the listener socket. Note that TFO server side will not retransmit anything other than SYN-ACK until the 3WHS is completed. The patch also contains an important function "reqsk_fastopen_remove()" to manage the somewhat complex relation between a listener, its request_sock, and the corresponding child socket. See the comment above the function for the detail. Signed-off-by: NH.K. Jerry Chu <hkchu@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <therbert@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 02 8月, 2012 1 次提交
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由 Ben Hutchings 提交于
Cache the device gso_max_segs in sock::sk_gso_max_segs and use it to limit the size of TSO skbs. This avoids the need to fall back to software GSO for local TCP senders. Signed-off-by: NBen Hutchings <bhutchings@solarflare.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 28 7月, 2012 1 次提交
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由 Hangbin Liu 提交于
TCP_USER_TIMEOUT is a TCP level socket option that takes an unsigned int. But patch "tcp: Add TCP_USER_TIMEOUT socket option"(dca43c75) didn't check the negative values. If a user assign -1 to it, the socket will set successfully and wait for 4294967295 miliseconds. This patch add a negative value check to avoid this issue. Signed-off-by: NHangbin Liu <liuhangbin@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 20 7月, 2012 1 次提交
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由 Yuchung Cheng 提交于
sendmsg() (or sendto()) with MSG_FASTOPEN is a combo of connect(2) and write(2). The application should replace connect() with it to send data in the opening SYN packet. For blocking socket, sendmsg() blocks until all the data are buffered locally and the handshake is completed like connect() call. It returns similar errno like connect() if the TCP handshake fails. For non-blocking socket, it returns the number of bytes queued (and transmitted in the SYN-data packet) if cookie is available. If cookie is not available, it transmits a data-less SYN packet with Fast Open cookie request option and returns -EINPROGRESS like connect(). Using MSG_FASTOPEN on connecting or connected socket will result in simlar errno like repeating connect() calls. Therefore the application should only use this flag on new sockets. The buffer size of sendmsg() is independent of the MSS of the connection. Signed-off-by: NYuchung Cheng <ycheng@google.com> Acked-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 12 7月, 2012 1 次提交
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由 Eric Dumazet 提交于
This introduce TSQ (TCP Small Queues) TSQ goal is to reduce number of TCP packets in xmit queues (qdisc & device queues), to reduce RTT and cwnd bias, part of the bufferbloat problem. sk->sk_wmem_alloc not allowed to grow above a given limit, allowing no more than ~128KB [1] per tcp socket in qdisc/dev layers at a given time. TSO packets are sized/capped to half the limit, so that we have two TSO packets in flight, allowing better bandwidth use. As a side effect, setting the limit to 40000 automatically reduces the standard gso max limit (65536) to 40000/2 : It can help to reduce latencies of high prio packets, having smaller TSO packets. This means we divert sock_wfree() to a tcp_wfree() handler, to queue/send following frames when skb_orphan() [2] is called for the already queued skbs. Results on my dev machines (tg3/ixgbe nics) are really impressive, using standard pfifo_fast, and with or without TSO/GSO. Without reduction of nominal bandwidth, we have reduction of buffering per bulk sender : < 1ms on Gbit (instead of 50ms with TSO) < 8ms on 100Mbit (instead of 132 ms) I no longer have 4 MBytes backlogged in qdisc by a single netperf session, and both side socket autotuning no longer use 4 Mbytes. As skb destructor cannot restart xmit itself ( as qdisc lock might be taken at this point ), we delegate the work to a tasklet. We use one tasklest per cpu for performance reasons. If tasklet finds a socket owned by the user, it sets TSQ_OWNED flag. This flag is tested in a new protocol method called from release_sock(), to eventually send new segments. [1] New /proc/sys/net/ipv4/tcp_limit_output_bytes tunable [2] skb_orphan() is usually called at TX completion time, but some drivers call it in their start_xmit() handler. These drivers should at least use BQL, or else a single TCP session can still fill the whole NIC TX ring, since TSQ will have no effect. Signed-off-by: NEric Dumazet <edumazet@google.com> Cc: Dave Taht <dave.taht@bufferbloat.net> Cc: Tom Herbert <therbert@google.com> Cc: Matt Mathis <mattmathis@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Nandita Dukkipati <nanditad@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 11 7月, 2012 2 次提交
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由 Ben Hutchings 提交于
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 David S. Miller 提交于
Maintain a local hash table of TCP dynamic metrics blobs. Computed TCP metrics are no longer maintained in the route metrics. The table uses RCU and an extremely simple hash so that it has low latency and low overhead. A simple hash is legitimate because we only make metrics blobs for fully established connections. Some tweaking of the default hash table sizes, metric timeouts, and the hash chain length limit certainly could use some tweaking. But the basic design seems sound. With help from Eric Dumazet and Joe Perches. Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 24 5月, 2012 1 次提交
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由 Tim Bird 提交于
UDP stack needs a minimum hash size value for proper operation and also uses alloc_large_system_hash() for proper NUMA distribution of its hash tables and automatic sizing depending on available system memory. On some low memory situations, udp_table_init() must ignore the alloc_large_system_hash() result and reallocs a bigger memory area. As we cannot easily free old hash table, we leak it and kmemleak can issue a warning. This patch adds a low limit parameter to alloc_large_system_hash() to solve this problem. We then specify UDP_HTABLE_SIZE_MIN for UDP/UDPLite hash table allocation. Reported-by: NMark Asselstine <mark.asselstine@windriver.com> Reported-by: NTim Bird <tim.bird@am.sony.com> Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 20 5月, 2012 1 次提交
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由 Eldad Zack 提交于
Replace simple_strtoul with kstrtoul in three similar occurrences, all setup handlers: * route.c: set_rhash_entries * tcp.c: set_thash_entries * udp.c: set_uhash_entries Also check if the conversion failed. Signed-off-by: NEldad Zack <eldad@fogrefinery.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 18 5月, 2012 2 次提交
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由 Willy Tarreau 提交于
Since recent changes on TCP splicing (starting with commits 2f533844 "tcp: allow splice() to build full TSO packets" and 35f9c09f "tcp: tcp_sendpages() should call tcp_push() once"), I started seeing massive stalls when forwarding traffic between two sockets using splice() when pipe buffers were larger than socket buffers. Latest changes (net: netdev_alloc_skb() use build_skb()) made the problem even more apparent. The reason seems to be that if do_tcp_sendpages() fails on out of memory condition without being able to send at least one byte, tcp_push() is not called and the buffers cannot be flushed. After applying the attached patch, I cannot reproduce the stalls at all and the data rate it perfectly stable and steady under any condition which previously caused the problem to be permanent. The issue seems to have been there since before the kernel migrated to git, which makes me think that the stalls I occasionally experienced with tux during stress-tests years ago were probably related to the same issue. This issue was first encountered on 3.0.31 and 3.2.17, so please backport to -stable. Signed-off-by: NWilly Tarreau <w@1wt.eu> Acked-by: NEric Dumazet <edumazet@google.com> Cc: <stable@vger.kernel.org>
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由 Eric Dumazet 提交于
bool conversions where possible. __inline__ -> inline space cleanups Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 17 5月, 2012 1 次提交
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由 Eric Dumazet 提交于
bool/const conversions where possible __inline__ -> inline space cleanups Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 16 5月, 2012 1 次提交
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由 Joe Perches 提交于
Standardize the net core ratelimited logging functions. Coalesce formats, align arguments. Change a printk then vprintk sequence to use printf extension %pV. Signed-off-by: NJoe Perches <joe@perches.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 11 5月, 2012 1 次提交
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由 Pavel Emelyanov 提交于
It actually works on the input queue and will use its read mem routines, thus it's better to have in in the tcp_input.c file. Signed-off-by: NPavel Emelyanov <xemul@parallels.com> Acked-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 03 5月, 2012 3 次提交
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由 Eric Dumazet 提交于
Extend tcp coalescing implementing it from tcp_queue_rcv(), the main receiver function when application is not blocked in recvmsg(). Function tcp_queue_rcv() is moved a bit to allow its call from tcp_data_queue() This gives good results especially if GRO could not kick, and if skb head is a fragment. Signed-off-by: NEric Dumazet <edumazet@google.com> Cc: Alexander Duyck <alexander.h.duyck@intel.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Eric Dumazet 提交于
tcp_adv_win_scale default value is 2, meaning we expect a good citizen skb to have skb->len / skb->truesize ratio of 75% (3/4) In 2.6 kernels we (mis)accounted for typical MSS=1460 frame : 1536 + 64 + 256 = 1856 'estimated truesize', and 1856 * 3/4 = 1392. So these skbs were considered as not bloated. With recent truesize fixes, a typical MSS=1460 frame truesize is now the more precise : 2048 + 256 = 2304. But 2304 * 3/4 = 1728. So these skb are not good citizen anymore, because 1460 < 1728 (GRO can escape this problem because it build skbs with a too low truesize.) This also means tcp advertises a too optimistic window for a given allocated rcvspace : When receiving frames, sk_rmem_alloc can hit sk_rcvbuf limit and we call tcp_prune_queue()/tcp_collapse() too often, especially when application is slow to drain its receive queue or in case of losses (netperf is fast, scp is slow). This is a major latency source. We should adjust the len/truesize ratio to 50% instead of 75% This patch : 1) changes tcp_adv_win_scale default to 1 instead of 2 2) increase tcp_rmem[2] limit from 4MB to 6MB to take into account better truesize tracking and to allow autotuning tcp receive window to reach same value than before. Note that same amount of kernel memory is consumed compared to 2.6 kernels. Signed-off-by: NEric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Yuchung Cheng <ycheng@google.com> Acked-by: NNeal Cardwell <ncardwell@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Yuchung Cheng 提交于
This patch implements RFC 5827 early retransmit (ER) for TCP. It reduces DUPACK threshold (dupthresh) if outstanding packets are less than 4 to recover losses by fast recovery instead of timeout. While the algorithm is simple, small but frequent network reordering makes this feature dangerous: the connection repeatedly enter false recovery and degrade performance. Therefore we implement a mitigation suggested in the appendix of the RFC that delays entering fast recovery by a small interval, i.e., RTT/4. Currently ER is conservative and is disabled for the rest of the connection after the first reordering event. A large scale web server experiment on the performance impact of ER is summarized in section 6 of the paper "Proportional Rate Reduction for TCP”, IMC 2011. http://conferences.sigcomm.org/imc/2011/docs/p155.pdf Note that Linux has a similar feature called THIN_DUPACK. The differences are THIN_DUPACK do not mitigate reorderings and is only used after slow start. Currently ER is disabled if THIN_DUPACK is enabled. I would be happy to merge THIN_DUPACK feature with ER if people think it's a good idea. ER is enabled by sysctl_tcp_early_retrans: 0: Disables ER 1: Reduce dupthresh to packets_out - 1 when outstanding packets < 4. 2: (Default) reduce dupthresh like mode 1. In addition, delay entering fast recovery by RTT/4. Note: mode 2 is implemented in the third part of this patch series. Signed-off-by: NYuchung Cheng <ycheng@google.com> Acked-by: NNeal Cardwell <ncardwell@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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