linux.git/net/ipv4/proc.c, branch v4.13 Linux kernel source tree tcp: add TCPMemoryPressuresChrono counter 2017-06-08T15:26:19+00:00 Eric Dumazet edumazet@google.com 2017-06-07T20:29:12+00:00 0604475119de5f80dc051a5db055c6a2a75bd542 DRAM supply shortage and poor memory pressure tracking in TCP stack makes any change in SO_SNDBUF/SO_RCVBUF (or equivalent autotuning limits) and tcp_mem[] quite hazardous. TCPMemoryPressures SNMP counter is an indication of tcp_mem sysctl limits being hit, but only tracking number of transitions. If TCP stack behavior under stress was perfect : 1) It would maintain memory usage close to the limit. 2) Memory pressure state would be entered for short times. We certainly prefer 100 events lasting 10ms compared to one event lasting 200 seconds. This patch adds a new SNMP counter tracking cumulative duration of memory pressure events, given in ms units. $ cat /proc/sys/net/ipv4/tcp_mem 3088 4117 6176 $ grep TCP /proc/net/sockstat TCP: inuse 180 orphan 0 tw 2 alloc 234 mem 4140 $ nstat -n ; sleep 10 ; nstat |grep Pressure TcpExtTCPMemoryPressures 1700 TcpExtTCPMemoryPressuresChrono 5209 v2: Used EXPORT_SYMBOL_GPL() instead of EXPORT_SYMBOL() as David instructed. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
DRAM supply shortage and poor memory pressure tracking in TCP
stack makes any change in SO_SNDBUF/SO_RCVBUF (or equivalent autotuning
limits) and tcp_mem[] quite hazardous.

TCPMemoryPressures SNMP counter is an indication of tcp_mem sysctl
limits being hit, but only tracking number of transitions.

If TCP stack behavior under stress was perfect :
1) It would maintain memory usage close to the limit.
2) Memory pressure state would be entered for short times.

We certainly prefer 100 events lasting 10ms compared to one event
lasting 200 seconds.

This patch adds a new SNMP counter tracking cumulative duration of
memory pressure events, given in ms units.

$ cat /proc/sys/net/ipv4/tcp_mem
3088    4117    6176
$ grep TCP /proc/net/sockstat
TCP: inuse 180 orphan 0 tw 2 alloc 234 mem 4140
$ nstat -n ; sleep 10 ; nstat |grep Pressure
TcpExtTCPMemoryPressures        1700
TcpExtTCPMemoryPressuresChrono  5209

v2: Used EXPORT_SYMBOL_GPL() instead of EXPORT_SYMBOL() as David
instructed.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/tcp_fastopen: Add snmp counter for blackhole detection 2017-04-24T18:27:17+00:00 Wei Wang weiwan@google.com 2017-04-20T21:45:47+00:00 46c2fa39877ed70415ee2b1acfb9129e956f6de4 This counter records the number of times the firewall blackhole issue is detected and active TFO is disabled. Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
This counter records the number of times the firewall blackhole issue is
detected and active TFO is disabled.

Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tcp: remove tcp_tw_recycle 2017-03-17T03:33:56+00:00 Soheil Hassas Yeganeh soheil@google.com 2017-03-15T20:30:46+00:00 4396e46187ca5070219b81773c4e65088dac50cc The tcp_tw_recycle was already broken for connections behind NAT, since the per-destination timestamp is not monotonically increasing for multiple machines behind a single destination address. After the randomization of TCP timestamp offsets in commit 8a5bd45f6616 (tcp: randomize tcp timestamp offsets for each connection), the tcp_tw_recycle is broken for all types of connections for the same reason: the timestamps received from a single machine is not monotonically increasing, anymore. Remove tcp_tw_recycle, since it is not functional. Also, remove the PAWSPassive SNMP counter since it is only used for tcp_tw_recycle, and simplify tcp_v4_route_req and tcp_v6_route_req since the strict argument is only set when tcp_tw_recycle is enabled. Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Cc: Lutz Vieweg <lvml@5t9.de> Cc: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net> 
The tcp_tw_recycle was already broken for connections
behind NAT, since the per-destination timestamp is not
monotonically increasing for multiple machines behind
a single destination address.

After the randomization of TCP timestamp offsets
in commit 8a5bd45f6616 (tcp: randomize tcp timestamp offsets
for each connection), the tcp_tw_recycle is broken for all
types of connections for the same reason: the timestamps
received from a single machine is not monotonically increasing,
anymore.

Remove tcp_tw_recycle, since it is not functional. Also, remove
the PAWSPassive SNMP counter since it is only used for
tcp_tw_recycle, and simplify tcp_v4_route_req and tcp_v6_route_req
since the strict argument is only set when tcp_tw_recycle is
enabled.

Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Cc: Lutz Vieweg <lvml@5t9.de>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: add LINUX_MIB_PFMEMALLOCDROP counter 2017-02-03T04:34:19+00:00 Eric Dumazet edumazet@google.com 2017-02-02T04:47:59+00:00 8fe809a992639b2013c0d8da2ba55cdea28a959a Debugging issues caused by pfmemalloc is often tedious. Add a new SNMP counter to more easily diagnose these problems. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Josef Bacik <jbacik@fb.com> Acked-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Debugging issues caused by pfmemalloc is often tedious.

Add a new SNMP counter to more easily diagnose these problems.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Josef Bacik <jbacik@fb.com>
Acked-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: remove bh disabling around percpu_counter accesses 2017-01-20T16:27:22+00:00 Eric Dumazet edumazet@google.com 2017-01-20T13:06:08+00:00 c2a2efbbfcb31bedcf81170fc1aa920255c33b8f Shaohua Li made percpu_counter irq safe in commit 098faf5805c8 ("percpu_counter: make APIs irq safe") We can safely remove BH disable/enable sections around various percpu_counter manipulations. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Shaohua Li made percpu_counter irq safe in commit 098faf5805c8
("percpu_counter: make APIs irq safe")

We can safely remove BH disable/enable sections around various
percpu_counter manipulations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ipv4: Namespaceify tcp_tw_recycle and tcp_max_tw_buckets knob 2016-12-29T16:38:31+00:00 Haishuang Yan yanhaishuang@cmss.chinamobile.com 2016-12-28T09:52:32+00:00 1946e672c173559155a3e210fe95dbf8b7b8ddf7 Different namespace application might require fast recycling TIME-WAIT sockets independently of the host. Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Different namespace application might require fast recycling
TIME-WAIT sockets independently of the host.

Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Suppress the "Comparison to NULL could be written" warnings 2016-09-30T05:50:45+00:00 Jia He hejianet@gmail.com 2016-09-30T03:29:04+00:00 6d4a741cbbfa6612a479656654ca5edf7becc72c This is to suppress the checkpatch.pl warning "Comparison to NULL could be written". No functional changes here. Signed-off-by: Jia He <hejianet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
This is to suppress the checkpatch.pl warning "Comparison to NULL
could be written". No functional changes here.

Signed-off-by: Jia He <hejianet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
proc: Reduce cache miss in snmp_seq_show 2016-09-30T05:50:44+00:00 Jia He hejianet@gmail.com 2016-09-30T03:28:59+00:00 f22d5c490990ecb6f4eb70c4ed478fc8cea78fe1 This is to use the generic interfaces snmp_get_cpu_field{,64}_batch to aggregate the data by going through all the items of each cpu sequentially. Then snmp_seq_show is split into 2 parts to avoid build warning "the frame size" larger than 1024. Signed-off-by: Jia He <hejianet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
This is to use the generic interfaces snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Then snmp_seq_show is split into 2 parts to avoid build warning "the frame
size" larger than 1024.

Signed-off-by: Jia He <hejianet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tcp: md5: add LINUX_MIB_TCPMD5FAILURE counter 2016-08-25T23:43:11+00:00 Eric Dumazet edumazet@google.com 2016-08-24T16:01:23+00:00 72145a68e4ee116533df49af4b87aca0aacc179c Adds SNMP counter for drops caused by MD5 mismatches. The current syslog might help, but a counter is more precise and helps monitoring. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Adds SNMP counter for drops caused by MD5 mismatches.

The current syslog might help, but a counter is more precise and helps
monitoring.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ipv4: Namespaceify ip_default_ttl sysctl knob 2016-02-17T01:42:54+00:00 Nikolay Borisov kernel@kyup.com 2016-02-15T10:11:27+00:00 fa50d974d104113630d68b7d03233a6686230d0c Signed-off-by: Nikolay Borisov <kernel@kyup.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>