- 08 6月, 2017 3 次提交
-
-
由 Eric Dumazet 提交于
Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 03 6月, 2017 1 次提交
-
-
由 Eric Dumazet 提交于
__pskb_trim_head() does not need to reset skb tail pointer. Also change the comments, __pskb_pull_head() does not exist. Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 18 5月, 2017 8 次提交
-
-
由 Eric Dumazet 提交于
TCP Timestamps option is defined in RFC 7323 Traditionally on linux, it has been tied to the internal 'jiffies' variable, because it had been a cheap and good enough generator. For TCP flows on the Internet, 1 ms resolution would be much better than 4ms or 10ms (HZ=250 or HZ=100 respectively) For TCP flows in the DC, Google has used usec resolution for more than two years with great success [1] Receive size autotuning (DRS) is indeed more precise and converges faster to optimal window size. This patch converts tp->tcp_mstamp to a plain u64 value storing a 1 usec TCP clock. This choice will allow us to upstream the 1 usec TS option as discussed in IETF 97. [1] https://www.ietf.org/proceedings/97/slides/slides-97-tcpm-tcp-options-for-low-latency-00.pdfSigned-off-by: NEric Dumazet <edumazet@google.com> Acked-by: NSoheil Hassas Yeganeh <soheil@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
After this patch, all uses of tcp_time_stamp will require a change when we introduce 1 ms and/or 1 us TCP TS option. Signed-off-by: NEric Dumazet <edumazet@google.com> Acked-by: NSoheil Hassas Yeganeh <soheil@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
tcp_time_stamp will no longer be tied to jiffies. Signed-off-by: NEric Dumazet <edumazet@google.com> Acked-by: NSoheil Hassas Yeganeh <soheil@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
Use tcp_jiffies32 instead of tcp_time_stamp, since tcp_time_stamp will soon be only used for TCP TS option. Signed-off-by: NEric Dumazet <edumazet@google.com> Acked-by: NSoheil Hassas Yeganeh <soheil@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
Use tcp_jiffies32 instead of tcp_time_stamp, since tcp_time_stamp will soon be only used for TCP TS option. Signed-off-by: NEric Dumazet <edumazet@google.com> Acked-by: NSoheil Hassas Yeganeh <soheil@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
Use tcp_jiffies32 instead of tcp_time_stamp to feed tp->snd_cwnd_stamp. tcp_time_stamp will soon be a litle bit more expensive than simply reading 'jiffies'. Signed-off-by: NEric Dumazet <edumazet@google.com> Acked-by: NSoheil Hassas Yeganeh <soheil@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
Use tcp_jiffies32 instead of tcp_time_stamp to feed tp->lsndtime. tcp_time_stamp will soon be a litle bit more expensive than simply reading 'jiffies'. Signed-off-by: NEric Dumazet <edumazet@google.com> Acked-by: NSoheil Hassas Yeganeh <soheil@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
Idea is to later convert tp->tcp_mstamp to a full u64 counter using usec resolution, so that we can later have fine grained TCP TS clock (RFC 7323), regardless of HZ value. We try to refresh tp->tcp_mstamp only when necessary. Signed-off-by: NEric Dumazet <edumazet@google.com> Acked-by: NSoheil Hassas Yeganeh <soheil@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 17 5月, 2017 1 次提交
-
-
由 Eric Dumazet 提交于
BBR congestion control depends on pacing, and pacing is currently handled by sch_fq packet scheduler for performance reasons, and also because implemening pacing with FQ was convenient to truly avoid bursts. However there are many cases where this packet scheduler constraint is not practical. - Many linux hosts are not focusing on handling thousands of TCP flows in the most efficient way. - Some routers use fq_codel or other AQM, but still would like to use BBR for the few TCP flows they initiate/terminate. This patch implements an automatic fallback to internal pacing. Pacing is requested either by BBR or use of SO_MAX_PACING_RATE option. If sch_fq happens to be in the egress path, pacing is delegated to the qdisc, otherwise pacing is done by TCP itself. One advantage of pacing from TCP stack is to get more precise rtt estimations, and less work done from TX completion, since TCP Small queue limits are not generally hit. Setups with single TX queue but many cpus might even benefit from this. Note that unlike sch_fq, we do not take into account header sizes. Taking care of these headers would add additional complexity for no practical differences in behavior. Some performance numbers using 800 TCP_STREAM flows rate limited to ~48 Mbit per second on 40Gbit NIC. If MQ+pfifo_fast is used on the NIC : $ sar -n DEV 1 5 | grep eth 14:48:44 eth0 725743.00 2932134.00 46776.76 4335184.68 0.00 0.00 1.00 14:48:45 eth0 725349.00 2932112.00 46751.86 4335158.90 0.00 0.00 0.00 14:48:46 eth0 725101.00 2931153.00 46735.07 4333748.63 0.00 0.00 0.00 14:48:47 eth0 725099.00 2931161.00 46735.11 4333760.44 0.00 0.00 1.00 14:48:48 eth0 725160.00 2931731.00 46738.88 4334606.07 0.00 0.00 0.00 Average: eth0 725290.40 2931658.20 46747.54 4334491.74 0.00 0.00 0.40 $ vmstat 1 5 procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 4 0 0 259825920 45644 2708324 0 0 21 2 247 98 0 0 100 0 0 4 0 0 259823744 45644 2708356 0 0 0 0 2400825 159843 0 19 81 0 0 0 0 0 259824208 45644 2708072 0 0 0 0 2407351 159929 0 19 81 0 0 1 0 0 259824592 45644 2708128 0 0 0 0 2405183 160386 0 19 80 0 0 1 0 0 259824272 45644 2707868 0 0 0 32 2396361 158037 0 19 81 0 0 Now use MQ+FQ : lpaa23:~# echo fq >/proc/sys/net/core/default_qdisc lpaa23:~# tc qdisc replace dev eth0 root mq $ sar -n DEV 1 5 | grep eth 14:49:57 eth0 678614.00 2727930.00 43739.13 4033279.14 0.00 0.00 0.00 14:49:58 eth0 677620.00 2723971.00 43674.69 4027429.62 0.00 0.00 1.00 14:49:59 eth0 676396.00 2719050.00 43596.83 4020125.02 0.00 0.00 0.00 14:50:00 eth0 675197.00 2714173.00 43518.62 4012938.90 0.00 0.00 1.00 14:50:01 eth0 676388.00 2719063.00 43595.47 4020171.64 0.00 0.00 0.00 Average: eth0 676843.00 2720837.40 43624.95 4022788.86 0.00 0.00 0.40 $ vmstat 1 5 procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 2 0 0 259832240 46008 2710912 0 0 21 2 223 192 0 1 99 0 0 1 0 0 259832896 46008 2710744 0 0 0 0 1702206 198078 0 17 82 0 0 0 0 0 259830272 46008 2710596 0 0 0 0 1696340 197756 1 17 83 0 0 4 0 0 259829168 46024 2710584 0 0 16 0 1688472 197158 1 17 82 0 0 3 0 0 259830224 46024 2710408 0 0 0 0 1692450 197212 0 18 82 0 0 As expected, number of interrupts per second is very different. Signed-off-by: NEric Dumazet <edumazet@google.com> Acked-by: NSoheil Hassas Yeganeh <soheil@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Van Jacobson <vanj@google.com> Cc: Jerry Chu <hkchu@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 09 5月, 2017 1 次提交
-
-
由 Wei Wang 提交于
Congestion control modules that want full control over congestion control behavior do not want the cwnd modifications controlled by the sysctl_tcp_slow_start_after_idle code path. So skip those code paths for CC modules that use the cong_control() API. As an example, those cwnd effects are not desired for the BBR congestion control algorithm. Fixes: c0402760 ("tcp: new CC hook to set sending rate with rate_sample in any CA state") Signed-off-by: NWei Wang <weiwan@google.com> Signed-off-by: NYuchung Cheng <ycheng@google.com> Signed-off-by: NNeal Cardwell <ncardwell@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 29 4月, 2017 1 次提交
-
-
由 Eric Dumazet 提交于
Andrey found a way to trigger the WARN_ON_ONCE(delta < len) in skb_try_coalesce() using syzkaller and a filter attached to a TCP socket over loopback interface. I believe one issue with looped skbs is that tcp_trim_head() can end up producing skb with under estimated truesize. It hardly matters for normal conditions, since packets sent over loopback are never truncated. Bytes trimmed from skb->head should not change skb truesize, since skb->head is not reallocated. Signed-off-by: NEric Dumazet <edumazet@google.com> Reported-by: NAndrey Konovalov <andreyknvl@google.com> Tested-by: NAndrey Konovalov <andreyknvl@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 08 4月, 2017 1 次提交
-
-
由 Gao Feng 提交于
Because TCP_MIB_OUTRSTS is an important count, so always increase it whatever send it successfully or not. Now move the increment of TCP_MIB_OUTRSTS to the top of tcp_send_active_reset to make sure it is increased always even though fail to alloc skb. Signed-off-by: NGao Feng <fgao@ikuai8.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 05 4月, 2017 1 次提交
-
-
由 Gao Feng 提交于
Define one new macro TCP_MAX_WSCALE instead of literal number '14', and use U16_MAX instead of 65535 as the max value of TCP window. There is another minor change, use rounddown(space, mss) instead of (space / mss) * mss; Signed-off-by: NGao Feng <fgao@ikuai8.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 31 3月, 2017 1 次提交
-
-
由 Gao Feng 提交于
1. Move the "window = tp->rcv_wnd;" into the condition block without tp->rx_opt.rcv_wscale. Because it is unnecessary when enable wscale; 2. Use the macro ALIGN instead of two statements. The two statements are used to make window align to 1<<wscale. Use the ALIGN is more clearer. 3. Use the rounddown to make codes clearer. Signed-off-by: NGao Feng <fgao@ikuai8.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 18 2月, 2017 1 次提交
-
-
由 Cui, Cheng 提交于
tcp: accommodate sequence number to a peer's shrunk receive window caused by precision loss in window scaling Prevent sending out a left-shifted sequence number from a Linux sender in response to a peer's shrunk receive-window caused by losing least significant bits in window-scaling. 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: NCheng Cui <Cheng.Cui@netapp.com> Acked-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 08 2月, 2017 1 次提交
-
-
由 Julian Anastasov 提交于
When same struct dst_entry can be used for many different neighbours we can not use it for pending confirmations. Use the new sk_dst_confirm() helper to propagate the indication from received packets to sock_confirm_neigh(). Reported-by: NYueHaibing <yuehaibing@huawei.com> Fixes: 5110effe ("net: Do delayed neigh confirmation.") Fixes: f2bb4bed ("ipv4: Cache output routes in fib_info nexthops.") Tested-by: NYueHaibing <yuehaibing@huawei.com> Signed-off-by: NJulian Anastasov <ja@ssi.bg> Acked-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 04 2月, 2017 2 次提交
-
-
由 Eric Dumazet 提交于
Josef Bacik diagnosed following problem : I was seeing random disconnects while testing NBD over loopback. This turned out to be because NBD sets pfmemalloc on it's socket, however the receiving side is a user space application so does not have pfmemalloc set on its socket. This means that sk_filter_trim_cap will simply drop this packet, under the assumption that the other side will simply retransmit. Well we do retransmit, and then the packet is just dropped again for the same reason. It seems the better way to address this problem is to clear pfmemalloc in the TCP transmit path. pfmemalloc strict control really makes sense on the receive path. Signed-off-by: NEric Dumazet <edumazet@google.com> Acked-by: NJosef Bacik <jbacik@fb.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
Small cleanup factorizing code doing the TCP_MAXSEG clamping. Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 02 2月, 2017 1 次提交
-
-
由 Eric Dumazet 提交于
syszkaller fuzzer was able to trigger a divide by zero, when TCP window scaling is not enabled. SO_RCVBUF can be used not only to increase sk_rcvbuf, also to decrease it below current receive buffers utilization. If mss is negative or 0, just return a zero TCP window. Signed-off-by: NEric Dumazet <edumazet@google.com> Reported-by: NDmitry Vyukov <dvyukov@google.com> Acked-by: NNeal Cardwell <ncardwell@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 30 1月, 2017 1 次提交
-
-
由 Yuchung Cheng 提交于
Currently the retransmission stats are not incremented if the retransmit fails locally. But we always increment the other packet counters that track total packet/bytes sent. Awkwardly while we don't count these failed retransmits in RETRANSSEGS, we do count them in FAILEDRETRANS. If the qdisc is dropping many packets this could under-estimate TCP retransmission rate substantially from both SNMP or per-socket TCP_INFO stats. This patch changes this by always incrementing retransmission stats on retransmission attempts and failures. Another motivation is to properly track retransmists in SCM_TIMESTAMPING_OPT_STATS. Since SCM_TSTAMP_SCHED collection is triggered in tcp_transmit_skb(), If tp->total_retrans is incremented after the function, we'll always mis-count by the amount of the latest retransmission. Signed-off-by: NYuchung Cheng <ycheng@google.com> Signed-off-by: NSoheil Hassas Yeganeh <soheil@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>
-
- 26 1月, 2017 1 次提交
-
-
由 Wei Wang 提交于
Refactor the cookie check logic in tcp_send_syn_data() into a function. This function will be called else where in later changes. Signed-off-by: NWei Wang <weiwan@google.com> Acked-by: NEric Dumazet <edumazet@google.com> Acked-by: NYuchung Cheng <ycheng@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 14 1月, 2017 3 次提交
-
-
由 Yuchung Cheng 提交于
This patch removes the support of RFC5827 early retransmit (i.e., fast recovery on small inflight with <3 dupacks) because it is subsumed by the new RACK loss detection. More specifically when RACK receives DUPACKs, it'll arm a reordering timer to start fast recovery after a quarter of (min)RTT, hence it covers the early retransmit except RACK does not limit itself to specific inflight or dupack numbers. Signed-off-by: NYuchung Cheng <ycheng@google.com> Signed-off-by: NNeal Cardwell <ncardwell@google.com> Acked-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Yuchung Cheng 提交于
Forward retransmit is an esoteric feature in RFC3517 (condition(3) in the NextSeg()). Basically if a packet is not considered lost by the current criteria (# of dupacks etc), but the congestion window has room for more packets, then retransmit this packet. However it actually conflicts with the rest of recovery design. For example, when reordering is detected we want to be conservative in retransmitting packets but forward-retransmit feature would break that to force more retransmission. Also the implementation is fairly complicated inside the retransmission logic inducing extra iterations in the write queue. With RACK losses are being detected timely and this heuristic is no longer necessary. There this patch removes the feature. Signed-off-by: NYuchung Cheng <ycheng@google.com> Signed-off-by: NNeal Cardwell <ncardwell@google.com> Acked-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Yuchung Cheng 提交于
This patch makes RACK install a reordering timer when it suspects some packets might be lost, but wants to delay the decision a little bit to accomodate reordering. It does not create a new timer but instead repurposes the existing RTO timer, because both are meant to retransmit packets. Specifically it arms a timer ICSK_TIME_REO_TIMEOUT when the RACK timing check fails. The wait time is set to RACK.RTT + RACK.reo_wnd - (NOW - Packet.xmit_time) + fudge This translates to expecting a packet (Packet) should take (RACK.RTT + RACK.reo_wnd + fudge) to deliver after it was sent. When there are multiple packets that need a timer, we use one timer with the maximum timeout. Therefore the timer conservatively uses the maximum window to expire N packets by one timeout, instead of N timeouts to expire N packets sent at different times. The fudge factor is 2 jiffies to ensure when the timer fires, all the suspected packets would exceed the deadline and be marked lost by tcp_rack_detect_loss(). It has to be at least 1 jiffy because the clock may tick between calling icsk_reset_xmit_timer(timeout) and actually hang the timer. The next jiffy is to lower-bound the timeout to 2 jiffies when reo_wnd is < 1ms. When the reordering timer fires (tcp_rack_reo_timeout): If we aren't in Recovery we'll enter fast recovery and force fast retransmit. This is very similar to the early retransmit (RFC5827) except RACK is not constrained to only enter recovery for small outstanding flights. Signed-off-by: NYuchung Cheng <ycheng@google.com> Signed-off-by: NNeal Cardwell <ncardwell@google.com> Acked-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 26 12月, 2016 1 次提交
-
-
由 Thomas Gleixner 提交于
ktime is a union because the initial implementation stored the time in scalar nanoseconds on 64 bit machine and in a endianess optimized timespec variant for 32bit machines. The Y2038 cleanup removed the timespec variant and switched everything to scalar nanoseconds. The union remained, but become completely pointless. Get rid of the union and just keep ktime_t as simple typedef of type s64. The conversion was done with coccinelle and some manual mopping up. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
-
- 22 12月, 2016 1 次提交
-
-
由 Eric Dumazet 提交于
Madalin reported crashes happening in tcp_tasklet_func() on powerpc64 Before TSQ_QUEUED bit is cleared, we must ensure the changes done by list_del(&tp->tsq_node); are committed to memory, otherwise corruption might happen, as an other cpu could catch TSQ_QUEUED clearance too soon. We can notice that old kernels were immune to this bug, because TSQ_QUEUED was cleared after a bh_lock_sock(sk)/bh_unlock_sock(sk) section, but they could have missed a kick to write additional bytes, when NIC interrupts for a given flow are spread to multiple cpus. Affected TCP flows would need an incoming ACK or RTO timer to add more packets to the pipe. So overall situation should be better now. Fixes: b223feb9 ("tcp: tsq: add shortcut in tcp_tasklet_func()") Signed-off-by: NEric Dumazet <edumazet@google.com> Reported-by: NMadalin Bucur <madalin.bucur@nxp.com> Tested-by: NMadalin Bucur <madalin.bucur@nxp.com> Tested-by: NXing Lei <xing.lei@nxp.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 06 12月, 2016 7 次提交
-
-
由 Eric Dumazet 提交于
tsq_flags being in the same cache line than sk_wmem_alloc makes a lot of sense. Both fields are changed from tcp_wfree() and more generally by various TSQ related functions. Prior patch made room in struct sock and added sk_tsq_flags, this patch deletes tsq_flags from struct tcp_sock. Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
Adding a likely() in tcp_mtu_probe() moves its code which used to be inlined in front of tcp_write_xmit() We still have a cache line miss to access icsk->icsk_mtup.enabled, we will probably have to reorganize fields to help data locality. Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
Always allow the two first skbs in write queue to be sent, regardless of sk_wmem_alloc/sk_pacing_rate values. This helps a lot in situations where TX completions are delayed either because of driver latencies or softirq latencies. Test is done with no cache line misses. Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
Under high load, tcp_wfree() has an atomic operation trying to schedule a tasklet over and over. We can schedule it only if our per cpu list was empty. Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
Under high stress, I've seen tcp_tasklet_func() consuming ~700 usec, handling ~150 tcp sockets. By setting TCP_TSQ_DEFERRED in tcp_wfree(), we give a chance for other cpus/threads entering tcp_write_xmit() to grab it, allowing tcp_tasklet_func() to skip sockets that already did an xmit cycle. In the future, we might give to ACK processing an increased budget to reduce even more tcp_tasklet_func() amount of work. Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
Instead of atomically clear TSQ_THROTTLED and atomically set TSQ_QUEUED bits, use one cmpxchg() to perform a single locked operation. Since the following patch will also set TCP_TSQ_DEFERRED here, this cmpxchg() will make this addition free. Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Eric Dumazet 提交于
This is a cleanup, to ease code review of following patches. Old 'enum tsq_flags' is renamed, and a new enumeration is added with the flags used in cmpxchg() operations as opposed to single bit operations. Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 03 12月, 2016 1 次提交
-
-
由 Florian Westphal 提交于
jiffies based timestamps allow for easy inference of number of devices behind NAT translators and also makes tracking of hosts simpler. commit ceaa1fef ("tcp: adding a per-socket timestamp offset") added the main infrastructure that is needed for per-connection ts randomization, in particular writing/reading the on-wire tcp header format takes the offset into account so rest of stack can use normal tcp_time_stamp (jiffies). So only two items are left: - add a tsoffset for request sockets - extend the tcp isn generator to also return another 32bit number in addition to the ISN. Re-use of ISN generator also means timestamps are still monotonically increasing for same connection quadruple, i.e. PAWS will still work. Includes fixes from Eric Dumazet. Signed-off-by: NFlorian Westphal <fw@strlen.de> Acked-by: NEric Dumazet <edumazet@google.com> Acked-by: NYuchung Cheng <ycheng@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 30 11月, 2016 2 次提交
-
-
由 Francis Yan 提交于
This patch measures the amount of time when TCP runs out of new data to send to the network due to insufficient send buffer, while TCP is still busy delivering (i.e. write queue is not empty). The goal is to indicate either the send buffer autotuning or user SO_SNDBUF setting has resulted network under-utilization. The measurement starts conservatively by checking various conditions to minimize false claims (i.e. under-estimation is more likely). The measurement stops when the SOCK_NOSPACE flag is cleared. But it does not account the time elapsed till the next application write. Also the measurement only starts if the sender is still busy sending data, s.t. the limit accounted is part of the total busy time. Signed-off-by: NFrancis Yan <francisyyan@gmail.com> Signed-off-by: NYuchung Cheng <ycheng@google.com> Signed-off-by: NSoheil Hassas Yeganeh <soheil@google.com> Acked-by: NNeal Cardwell <ncardwell@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
由 Francis Yan 提交于
This patch measures the total time when the TCP stops sending because the receiver's advertised window is not large enough. Note that once the limit is lifted we are likely in the busy status if we have data pending. Signed-off-by: NFrancis Yan <francisyyan@gmail.com> Signed-off-by: NYuchung Cheng <ycheng@google.com> Signed-off-by: NSoheil Hassas Yeganeh <soheil@google.com> Acked-by: NNeal Cardwell <ncardwell@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-