<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/Documentation/networking, branch v5.0-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2019-01-03T20:53:47+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-01-03T20:53:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=43d86ee8c639df750529b4d8f062b328b61c423e'/>
<id>43d86ee8c639df750529b4d8f062b328b61c423e</id>
<content type='text'>
Pull networking fixes from David Miller:
 "Several fixes here. Basically split down the line between newly
  introduced regressions and long existing problems:

   1) Double free in tipc_enable_bearer(), from Cong Wang.

   2) Many fixes to nf_conncount, from Florian Westphal.

   3) op-&gt;get_regs_len() can throw an error, check it, from Yunsheng
      Lin.

   4) Need to use GFP_ATOMIC in *_add_hash_mac_address() of fsl/fman
      driver, from Scott Wood.

   5) Inifnite loop in fib_empty_table(), from Yue Haibing.

   6) Use after free in ax25_fillin_cb(), from Cong Wang.

   7) Fix socket locking in nr_find_socket(), also from Cong Wang.

   8) Fix WoL wakeup enable in r8169, from Heiner Kallweit.

   9) On 32-bit sock-&gt;sk_stamp is not thread-safe, from Deepa Dinamani.

  10) Fix ptr_ring wrap during queue swap, from Cong Wang.

  11) Missing shutdown callback in hinic driver, from Xue Chaojing.

  12) Need to return NULL on error from ip6_neigh_lookup(), from Stefano
      Brivio.

  13) BPF out of bounds speculation fixes from Daniel Borkmann"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (57 commits)
  ipv6: Consider sk_bound_dev_if when binding a socket to an address
  ipv6: Fix dump of specific table with strict checking
  bpf: add various test cases to selftests
  bpf: prevent out of bounds speculation on pointer arithmetic
  bpf: fix check_map_access smin_value test when pointer contains offset
  bpf: restrict unknown scalars of mixed signed bounds for unprivileged
  bpf: restrict stack pointer arithmetic for unprivileged
  bpf: restrict map value pointer arithmetic for unprivileged
  bpf: enable access to ax register also from verifier rewrite
  bpf: move tmp variable into ax register in interpreter
  bpf: move {prev_,}insn_idx into verifier env
  isdn: fix kernel-infoleak in capi_unlocked_ioctl
  ipv6: route: Fix return value of ip6_neigh_lookup() on neigh_create() error
  net/hamradio/6pack: use mod_timer() to rearm timers
  net-next/hinic:add shutdown callback
  net: hns3: call hns3_nic_net_open() while doing HNAE3_UP_CLIENT
  ip: validate header length on virtual device xmit
  tap: call skb_probe_transport_header after setting skb-&gt;dev
  ptr_ring: wrap back -&gt;producer in __ptr_ring_swap_queue()
  net: rds: remove unnecessary NULL check
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking fixes from David Miller:
 "Several fixes here. Basically split down the line between newly
  introduced regressions and long existing problems:

   1) Double free in tipc_enable_bearer(), from Cong Wang.

   2) Many fixes to nf_conncount, from Florian Westphal.

   3) op-&gt;get_regs_len() can throw an error, check it, from Yunsheng
      Lin.

   4) Need to use GFP_ATOMIC in *_add_hash_mac_address() of fsl/fman
      driver, from Scott Wood.

   5) Inifnite loop in fib_empty_table(), from Yue Haibing.

   6) Use after free in ax25_fillin_cb(), from Cong Wang.

   7) Fix socket locking in nr_find_socket(), also from Cong Wang.

   8) Fix WoL wakeup enable in r8169, from Heiner Kallweit.

   9) On 32-bit sock-&gt;sk_stamp is not thread-safe, from Deepa Dinamani.

  10) Fix ptr_ring wrap during queue swap, from Cong Wang.

  11) Missing shutdown callback in hinic driver, from Xue Chaojing.

  12) Need to return NULL on error from ip6_neigh_lookup(), from Stefano
      Brivio.

  13) BPF out of bounds speculation fixes from Daniel Borkmann"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (57 commits)
  ipv6: Consider sk_bound_dev_if when binding a socket to an address
  ipv6: Fix dump of specific table with strict checking
  bpf: add various test cases to selftests
  bpf: prevent out of bounds speculation on pointer arithmetic
  bpf: fix check_map_access smin_value test when pointer contains offset
  bpf: restrict unknown scalars of mixed signed bounds for unprivileged
  bpf: restrict stack pointer arithmetic for unprivileged
  bpf: restrict map value pointer arithmetic for unprivileged
  bpf: enable access to ax register also from verifier rewrite
  bpf: move tmp variable into ax register in interpreter
  bpf: move {prev_,}insn_idx into verifier env
  isdn: fix kernel-infoleak in capi_unlocked_ioctl
  ipv6: route: Fix return value of ip6_neigh_lookup() on neigh_create() error
  net/hamradio/6pack: use mod_timer() to rearm timers
  net-next/hinic:add shutdown callback
  net: hns3: call hns3_nic_net_open() while doing HNAE3_UP_CLIENT
  ip: validate header length on virtual device xmit
  tap: call skb_probe_transport_header after setting skb-&gt;dev
  ptr_ring: wrap back -&gt;producer in __ptr_ring_swap_queue()
  net: rds: remove unnecessary NULL check
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>add document for TCP OFO, PAWS and skip ACK counters</title>
<updated>2019-01-01T17:51:14+00:00</updated>
<author>
<name>yupeng</name>
<email>yupeng0921@gmail.com</email>
</author>
<published>2018-12-30T05:46:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2b96547223e3a036efb51733dbf37a1e4be92068'/>
<id>2b96547223e3a036efb51733dbf37a1e4be92068</id>
<content type='text'>
add document and examples for below counters:
TcpExtTCPOFOQueue
TcpExtTCPOFODrop
TcpExtTCPOFOMerge
TcpExtPAWSActive
TcpExtPAWSEstab
TcpExtTCPACKSkippedSynRecv
TcpExtTCPACKSkippedPAWS
TcpExtTCPACKSkippedSeq
TcpExtTCPACKSkippedFinWait2
TcpExtTCPACKSkippedTimeWait
TcpExtTCPACKSkippedChallenge

Signed-off-by: yupeng &lt;yupeng0921@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
add document and examples for below counters:
TcpExtTCPOFOQueue
TcpExtTCPOFODrop
TcpExtTCPOFOMerge
TcpExtPAWSActive
TcpExtPAWSEstab
TcpExtTCPACKSkippedSynRecv
TcpExtTCPACKSkippedPAWS
TcpExtTCPACKSkippedSeq
TcpExtTCPACKSkippedFinWait2
TcpExtTCPACKSkippedTimeWait
TcpExtTCPACKSkippedChallenge

Signed-off-by: yupeng &lt;yupeng0921@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'docs-5.0' of git://git.lwn.net/linux</title>
<updated>2018-12-29T19:21:49+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-12-29T19:21:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3868772b99e3146d02cf47e739d79022eba1d77c'/>
<id>3868772b99e3146d02cf47e739d79022eba1d77c</id>
<content type='text'>
Pull documentation update from Jonathan Corbet:
 "A fairly normal cycle for documentation stuff. We have a new document
  on perf security, more Italian translations, more improvements to the
  memory-management docs, improvements to the pathname lookup
  documentation, and the usual array of smaller fixes.

  As is often the case, there are a few reaches outside of
  Documentation/ to adjust kerneldoc comments"

* tag 'docs-5.0' of git://git.lwn.net/linux: (38 commits)
  docs: improve pathname-lookup document structure
  configfs: fix wrong name of struct in documentation
  docs/mm-api: link slab_common.c to "The Slab Cache" section
  slab: make kmem_cache_create{_usercopy} description proper kernel-doc
  doc:process: add links where missing
  docs/core-api: make mm-api.rst more structured
  x86, boot: documentation whitespace fixup
  Documentation: devres: note checking needs when converting
  doc:it: add some process/* translations
  doc:it: fixes in process/1.Intro
  Documentation: convert path-lookup from markdown to resturctured text
  Documentation/admin-guide: update admin-guide index.rst
  Documentation/admin-guide: introduce perf-security.rst file
  scripts/kernel-doc: Fix struct and struct field attribute processing
  Documentation: dev-tools: Fix typos in index.rst
  Correct gen_init_cpio tool's documentation
  Document /proc/pid PID reuse behavior
  Documentation: update path-lookup.md for parallel lookups
  Documentation: Use "while" instead of "whilst"
  dmaengine: Add mailing list address to the documentation
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull documentation update from Jonathan Corbet:
 "A fairly normal cycle for documentation stuff. We have a new document
  on perf security, more Italian translations, more improvements to the
  memory-management docs, improvements to the pathname lookup
  documentation, and the usual array of smaller fixes.

  As is often the case, there are a few reaches outside of
  Documentation/ to adjust kerneldoc comments"

* tag 'docs-5.0' of git://git.lwn.net/linux: (38 commits)
  docs: improve pathname-lookup document structure
  configfs: fix wrong name of struct in documentation
  docs/mm-api: link slab_common.c to "The Slab Cache" section
  slab: make kmem_cache_create{_usercopy} description proper kernel-doc
  doc:process: add links where missing
  docs/core-api: make mm-api.rst more structured
  x86, boot: documentation whitespace fixup
  Documentation: devres: note checking needs when converting
  doc:it: add some process/* translations
  doc:it: fixes in process/1.Intro
  Documentation: convert path-lookup from markdown to resturctured text
  Documentation/admin-guide: update admin-guide index.rst
  Documentation/admin-guide: introduce perf-security.rst file
  scripts/kernel-doc: Fix struct and struct field attribute processing
  Documentation: dev-tools: Fix typos in index.rst
  Correct gen_init_cpio tool's documentation
  Document /proc/pid PID reuse behavior
  Documentation: update path-lookup.md for parallel lookups
  Documentation: Use "while" instead of "whilst"
  dmaengine: Add mailing list address to the documentation
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next</title>
<updated>2018-12-21T02:20:26+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2018-12-21T02:20:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c3e533692527046fb55020e7fac8c4272644ba45'/>
<id>c3e533692527046fb55020e7fac8c4272644ba45</id>
<content type='text'>
Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for net-next:

1) Support for destination MAC in ipset, from Stefano Brivio.

2) Disallow all-zeroes MAC address in ipset, also from Stefano.

3) Add IPSET_CMD_GET_BYNAME and IPSET_CMD_GET_BYINDEX commands,
   introduce protocol version number 7, from Jozsef Kadlecsik.
   A follow up patch to fix ip_set_byindex() is also included
   in this batch.

4) Honor CTA_MARK_MASK from ctnetlink, from Andreas Jaggi.

5) Statify nf_flow_table_iterate(), from Taehee Yoo.

6) Use nf_flow_table_iterate() to simplify garbage collection in
   nf_flow_table logic, also from Taehee Yoo.

7) Don't use _bh variants of call_rcu(), rcu_barrier() and
   synchronize_rcu_bh() in Netfilter, from Paul E. McKenney.

8) Remove NFC_* cache definition from the old caching
   infrastructure.

9) Remove layer 4 port rover in NAT helpers, use random port
   instead, from Florian Westphal.

10) Use strscpy() in ipset, from Qian Cai.

11) Remove NF_NAT_RANGE_PROTO_RANDOM_FULLY branch now that
    random port is allocated by default, from Xiaozhou Liu.

12) Ignore NF_NAT_RANGE_PROTO_RANDOM too, from Florian Westphal.

13) Limit port allocation selection routine in NAT to avoid
    softlockup splats when most ports are in use, from Florian.

14) Remove unused parameters in nf_ct_l4proto_unregister_sysctl()
    from Yafang Shao.

15) Direct call to nf_nat_l4proto_unique_tuple() instead of
    indirection, from Florian Westphal.

16) Several patches to remove all layer 4 NAT indirections,
    remove nf_nat_l4proto struct, from Florian Westphal.

17) Fix RTP/RTCP source port translation when SNAT is in place,
    from Alin Nastac.

18) Selective rule dump per chain, from Phil Sutter.

19) Revisit CLUSTERIP target, this includes a deadlock fix from
    netns path, sleep in atomic, remove bogus WARN_ON_ONCE()
    and disallow mismatching IP address and MAC address.
    Patchset from Taehee Yoo.

20) Update UDP timeout to stream after 2 seconds, from Florian.

21) Shrink UDP established timeout to 120 seconds like TCP timewait.

22) Sysctl knobs to set GRE timeouts, from Yafang Shao.

23) Move seq_print_acct() to conntrack core file, from Florian.

24) Add enum for conntrack sysctl knobs, also from Florian.

25) Place nf_conntrack_acct, nf_conntrack_helper, nf_conntrack_events
    and nf_conntrack_timestamp knobs in the core, from Florian Westphal.
    As a side effect, shrink netns_ct structure by removing obsolete
    sysctl anchors, also from Florian.
====================

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for net-next:

1) Support for destination MAC in ipset, from Stefano Brivio.

2) Disallow all-zeroes MAC address in ipset, also from Stefano.

3) Add IPSET_CMD_GET_BYNAME and IPSET_CMD_GET_BYINDEX commands,
   introduce protocol version number 7, from Jozsef Kadlecsik.
   A follow up patch to fix ip_set_byindex() is also included
   in this batch.

4) Honor CTA_MARK_MASK from ctnetlink, from Andreas Jaggi.

5) Statify nf_flow_table_iterate(), from Taehee Yoo.

6) Use nf_flow_table_iterate() to simplify garbage collection in
   nf_flow_table logic, also from Taehee Yoo.

7) Don't use _bh variants of call_rcu(), rcu_barrier() and
   synchronize_rcu_bh() in Netfilter, from Paul E. McKenney.

8) Remove NFC_* cache definition from the old caching
   infrastructure.

9) Remove layer 4 port rover in NAT helpers, use random port
   instead, from Florian Westphal.

10) Use strscpy() in ipset, from Qian Cai.

11) Remove NF_NAT_RANGE_PROTO_RANDOM_FULLY branch now that
    random port is allocated by default, from Xiaozhou Liu.

12) Ignore NF_NAT_RANGE_PROTO_RANDOM too, from Florian Westphal.

13) Limit port allocation selection routine in NAT to avoid
    softlockup splats when most ports are in use, from Florian.

14) Remove unused parameters in nf_ct_l4proto_unregister_sysctl()
    from Yafang Shao.

15) Direct call to nf_nat_l4proto_unique_tuple() instead of
    indirection, from Florian Westphal.

16) Several patches to remove all layer 4 NAT indirections,
    remove nf_nat_l4proto struct, from Florian Westphal.

17) Fix RTP/RTCP source port translation when SNAT is in place,
    from Alin Nastac.

18) Selective rule dump per chain, from Phil Sutter.

19) Revisit CLUSTERIP target, this includes a deadlock fix from
    netns path, sleep in atomic, remove bogus WARN_ON_ONCE()
    and disallow mismatching IP address and MAC address.
    Patchset from Taehee Yoo.

20) Update UDP timeout to stream after 2 seconds, from Florian.

21) Shrink UDP established timeout to 120 seconds like TCP timewait.

22) Sysctl knobs to set GRE timeouts, from Yafang Shao.

23) Move seq_print_acct() to conntrack core file, from Florian.

24) Add enum for conntrack sysctl knobs, also from Florian.

25) Place nf_conntrack_acct, nf_conntrack_helper, nf_conntrack_events
    and nf_conntrack_timestamp knobs in the core, from Florian Westphal.
    As a side effect, shrink netns_ct structure by removing obsolete
    sysctl anchors, also from Florian.
====================

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: conntrack: register sysctl table for gre</title>
<updated>2018-12-20T23:51:25+00:00</updated>
<author>
<name>Yafang Shao</name>
<email>laoar.shao@gmail.com</email>
</author>
<published>2018-12-18T13:14:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a0badcc6652f9871a9908d67297f910cba657b0f'/>
<id>a0badcc6652f9871a9908d67297f910cba657b0f</id>
<content type='text'>
This patch adds two sysctl knobs for GRE:

	net.netfilter.nf_conntrack_gre_timeout = 30
	net.netfilter.nf_conntrack_gre_timeout_stream = 180

Update the Documentation as well.

Signed-off-by: Yafang Shao &lt;laoar.shao@gmail.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch adds two sysctl knobs for GRE:

	net.netfilter.nf_conntrack_gre_timeout = 30
	net.netfilter.nf_conntrack_gre_timeout_stream = 180

Update the Documentation as well.

Signed-off-by: Yafang Shao &lt;laoar.shao@gmail.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: conntrack: udp: set stream timeout to 2 minutes</title>
<updated>2018-12-20T23:48:46+00:00</updated>
<author>
<name>Florian Westphal</name>
<email>fw@strlen.de</email>
</author>
<published>2018-12-17T23:05:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=294304e4c522d797b7ea8200ab74354843fa68e9'/>
<id>294304e4c522d797b7ea8200ab74354843fa68e9</id>
<content type='text'>
We have no explicit signal when a UDP stream has terminated, peers just
stop sending.

For suspected stream connections a timeout of two minutes is sane to keep
NAT mapping alive a while longer.

It matches tcp conntracks 'timewait' default timeout value.

Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We have no explicit signal when a UDP stream has terminated, peers just
stop sending.

For suspected stream connections a timeout of two minutes is sane to keep
NAT mapping alive a while longer.

It matches tcp conntracks 'timewait' default timeout value.

Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Documentation: igb: Add a section about CBS</title>
<updated>2018-12-20T19:50:54+00:00</updated>
<author>
<name>Vinicius Costa Gomes</name>
<email>vinicius.gomes@intel.com</email>
</author>
<published>2018-11-17T00:19:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bad87ee82f74707913a27f16d40cd8a1c340b47e'/>
<id>bad87ee82f74707913a27f16d40cd8a1c340b47e</id>
<content type='text'>
Add some pointers to the definition of the CBS algorithm, and some
notes about the limits of its implementation in the i210 family of
controllers.

Signed-off-by: Vinicius Costa Gomes &lt;vinicius.gomes@intel.com&gt;
Tested-by: Aaron Brown &lt;aaron.f.brown@intel.com&gt;
Signed-off-by: Jeff Kirsher &lt;jeffrey.t.kirsher@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add some pointers to the definition of the CBS algorithm, and some
notes about the limits of its implementation in the i210 family of
controllers.

Signed-off-by: Vinicius Costa Gomes &lt;vinicius.gomes@intel.com&gt;
Tested-by: Aaron Brown &lt;aaron.f.brown@intel.com&gt;
Signed-off-by: Jeff Kirsher &lt;jeffrey.t.kirsher@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: switch secpath to use skb extension infrastructure</title>
<updated>2018-12-19T19:21:38+00:00</updated>
<author>
<name>Florian Westphal</name>
<email>fw@strlen.de</email>
</author>
<published>2018-12-18T16:15:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4165079ba328dd47262a2183049d3591f0a750b1'/>
<id>4165079ba328dd47262a2183049d3591f0a750b1</id>
<content type='text'>
Remove skb-&gt;sp and allocate secpath storage via extension
infrastructure.  This also reduces sk_buff by 8 bytes on x86_64.

Total size of allyesconfig kernel is reduced slightly, as there is
less inlined code (one conditional atomic op instead of two on
skb_clone).

No differences in throughput in following ipsec performance tests:
- transport mode with aes on 10GB link
- tunnel mode between two network namespaces with aes and null cipher

Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove skb-&gt;sp and allocate secpath storage via extension
infrastructure.  This also reduces sk_buff by 8 bytes on x86_64.

Total size of allyesconfig kernel is reduced slightly, as there is
less inlined code (one conditional atomic op instead of two on
skb_clone).

No differences in throughput in following ipsec performance tests:
- transport mode with aes on 10GB link
- tunnel mode between two network namespaces with aes and null cipher

Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>add snmp counters document</title>
<updated>2018-12-14T23:50:14+00:00</updated>
<author>
<name>yupeng</name>
<email>yupeng0921@gmail.com</email>
</author>
<published>2018-12-12T08:14:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8e2ea53a83dfb4b892ba35ddd9e78e6091202fa6'/>
<id>8e2ea53a83dfb4b892ba35ddd9e78e6091202fa6</id>
<content type='text'>
Add explainations for some general IP counters, SACK and DSACK related
counters

Signed-off-by: yupeng &lt;yupeng0921@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add explainations for some general IP counters, SACK and DSACK related
counters

Signed-off-by: yupeng &lt;yupeng0921@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>neighbor: Improve garbage collection</title>
<updated>2018-12-08T00:03:10+00:00</updated>
<author>
<name>David Ahern</name>
<email>dsahern@gmail.com</email>
</author>
<published>2018-12-07T20:24:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=58956317c8de52009d1a38a721474c24aef74fe7'/>
<id>58956317c8de52009d1a38a721474c24aef74fe7</id>
<content type='text'>
The existing garbage collection algorithm has a number of problems:

1. The gc algorithm will not evict PERMANENT entries as those entries
   are managed by userspace, yet the existing algorithm walks the entire
   hash table which means it always considers PERMANENT entries when
   looking for entries to evict. In some use cases (e.g., EVPN) there
   can be tens of thousands of PERMANENT entries leading to wasted
   CPU cycles when gc kicks in. As an example, with 32k permanent
   entries, neigh_alloc has been observed taking more than 4 msec per
   invocation.

2. Currently, when the number of neighbor entries hits gc_thresh2 and
   the last flush for the table was more than 5 seconds ago gc kicks in
   walks the entire hash table evicting *all* entries not in PERMANENT
   or REACHABLE state and not marked as externally learned. There is no
   discriminator on when the neigh entry was created or if it just moved
   from REACHABLE to another NUD_VALID state (e.g., NUD_STALE).

   It is possible for entries to be created or for established neighbor
   entries to be moved to STALE (e.g., an external node sends an ARP
   request) right before the 5 second window lapses:

        -----|---------x|----------|-----
            t-5         t         t+5

   If that happens those entries are evicted during gc causing unnecessary
   thrashing on neighbor entries and userspace caches trying to track them.

   Further, this contradicts the description of gc_thresh2 which says
   "Entries older than 5 seconds will be cleared".

   One workaround is to make gc_thresh2 == gc_thresh3 but that negates the
   whole point of having separate thresholds.

3. Clearing *all* neigh non-PERMANENT/REACHABLE/externally learned entries
   when gc_thresh2 is exceeded is over kill and contributes to trashing
   especially during startup.

This patch addresses these problems as follows:

1. Use of a separate list_head to track entries that can be garbage
   collected along with a separate counter. PERMANENT entries are not
   added to this list.

   The gc_thresh parameters are only compared to the new counter, not the
   total entries in the table. The forced_gc function is updated to only
   walk this new gc_list looking for entries to evict.

2. Entries are added to the list head at the tail and removed from the
   front.

3. Entries are only evicted if they were last updated more than 5 seconds
   ago, adhering to the original intent of gc_thresh2.

4. Forced gc is stopped once the number of gc_entries drops below
   gc_thresh2.

5. Since gc checks do not apply to PERMANENT entries, gc levels are skipped
   when allocating a new neighbor for a PERMANENT entry. By extension this
   means there are no explicit limits on the number of PERMANENT entries
   that can be created, but this is no different than FIB entries or FDB
   entries.

Signed-off-by: David Ahern &lt;dsahern@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The existing garbage collection algorithm has a number of problems:

1. The gc algorithm will not evict PERMANENT entries as those entries
   are managed by userspace, yet the existing algorithm walks the entire
   hash table which means it always considers PERMANENT entries when
   looking for entries to evict. In some use cases (e.g., EVPN) there
   can be tens of thousands of PERMANENT entries leading to wasted
   CPU cycles when gc kicks in. As an example, with 32k permanent
   entries, neigh_alloc has been observed taking more than 4 msec per
   invocation.

2. Currently, when the number of neighbor entries hits gc_thresh2 and
   the last flush for the table was more than 5 seconds ago gc kicks in
   walks the entire hash table evicting *all* entries not in PERMANENT
   or REACHABLE state and not marked as externally learned. There is no
   discriminator on when the neigh entry was created or if it just moved
   from REACHABLE to another NUD_VALID state (e.g., NUD_STALE).

   It is possible for entries to be created or for established neighbor
   entries to be moved to STALE (e.g., an external node sends an ARP
   request) right before the 5 second window lapses:

        -----|---------x|----------|-----
            t-5         t         t+5

   If that happens those entries are evicted during gc causing unnecessary
   thrashing on neighbor entries and userspace caches trying to track them.

   Further, this contradicts the description of gc_thresh2 which says
   "Entries older than 5 seconds will be cleared".

   One workaround is to make gc_thresh2 == gc_thresh3 but that negates the
   whole point of having separate thresholds.

3. Clearing *all* neigh non-PERMANENT/REACHABLE/externally learned entries
   when gc_thresh2 is exceeded is over kill and contributes to trashing
   especially during startup.

This patch addresses these problems as follows:

1. Use of a separate list_head to track entries that can be garbage
   collected along with a separate counter. PERMANENT entries are not
   added to this list.

   The gc_thresh parameters are only compared to the new counter, not the
   total entries in the table. The forced_gc function is updated to only
   walk this new gc_list looking for entries to evict.

2. Entries are added to the list head at the tail and removed from the
   front.

3. Entries are only evicted if they were last updated more than 5 seconds
   ago, adhering to the original intent of gc_thresh2.

4. Forced gc is stopped once the number of gc_entries drops below
   gc_thresh2.

5. Since gc checks do not apply to PERMANENT entries, gc levels are skipped
   when allocating a new neighbor for a PERMANENT entry. By extension this
   means there are no explicit limits on the number of PERMANENT entries
   that can be created, but this is no different than FIB entries or FDB
   entries.

Signed-off-by: David Ahern &lt;dsahern@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
</feed>
