<feed xmlns='http://www.w3.org/2005/Atom'>
<title>BMC/Intel-BMC/linux.git/net/sctp, branch dev-4.6</title>
<subtitle>Intel OpenBMC Linux kernel source tree (mirror)</subtitle>
<id>https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev-4.6</id>
<link rel='self' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev-4.6'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/'/>
<updated>2016-04-11T02:22:34+00:00</updated>
<entry>
<title>sctp: avoid refreshing heartbeat timer too often</title>
<updated>2016-04-11T02:22:34+00:00</updated>
<author>
<name>Marcelo Ricardo Leitner</name>
<email>marcelo.leitner@gmail.com</email>
</author>
<published>2016-04-06T18:15:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=ba6f5e33bdbb9ed2014b778fbbaecf20060ca989'/>
<id>urn:sha1:ba6f5e33bdbb9ed2014b778fbbaecf20060ca989</id>
<content type='text'>
Currently on high rate SCTP streams the heartbeat timer refresh can
consume quite a lot of resources as timer updates are costly and it
contains a random factor, which a) is also costly and b) invalidates
mod_timer() optimization for not editing a timer to the same value.
It may even cause the timer to be slightly advanced, for no good reason.

As suggested by David Laight this patch now removes this timer update
from hot path by leaving the timer on and re-evaluating upon its
expiration if the heartbeat is still needed or not, similarly to what is
done for TCP. If it's not needed anymore the timer is re-scheduled to
the new timeout, considering the time already elapsed.

For this, we now record the last tx timestamp per transport, updated in
the same spots as hb timer was restarted on tx. Also split up
sctp_transport_reset_timers into sctp_transport_reset_t3_rtx and
sctp_transport_reset_hb_timer, so we can re-arm T3 without re-arming the
heartbeat one.

On loopback with MTU of 65535 and data chunks with 1636, so that we
have a considerable amount of chunks without stressing system calls,
netperf -t SCTP_STREAM -l 30, perf looked like this before:

Samples: 103K of event 'cpu-clock', Event count (approx.): 25833000000
  Overhead  Command  Shared Object      Symbol
+    6,15%  netperf  [kernel.vmlinux]   [k] copy_user_enhanced_fast_string
-    5,43%  netperf  [kernel.vmlinux]   [k] _raw_write_unlock_irqrestore
   - _raw_write_unlock_irqrestore
      - 96,54% _raw_spin_unlock_irqrestore
         - 36,14% mod_timer
            + 97,24% sctp_transport_reset_timers
            + 2,76% sctp_do_sm
         + 33,65% __wake_up_sync_key
         + 28,77% sctp_ulpq_tail_event
         + 1,40% del_timer
      - 1,84% mod_timer
         + 99,03% sctp_transport_reset_timers
         + 0,97% sctp_do_sm
      + 1,50% sctp_ulpq_tail_event

And after this patch, now with netperf -l 60:

Samples: 230K of event 'cpu-clock', Event count (approx.): 57707250000
  Overhead  Command  Shared Object      Symbol
+    5,65%  netperf  [kernel.vmlinux]   [k] memcpy_erms
+    5,59%  netperf  [kernel.vmlinux]   [k] copy_user_enhanced_fast_string
-    5,05%  netperf  [kernel.vmlinux]   [k] _raw_spin_unlock_irqrestore
   - _raw_spin_unlock_irqrestore
      + 49,89% __wake_up_sync_key
      + 45,68% sctp_ulpq_tail_event
      - 2,85% mod_timer
         + 76,51% sctp_transport_reset_t3_rtx
         + 23,49% sctp_do_sm
      + 1,55% del_timer
+    2,50%  netperf  [sctp]             [k] sctp_datamsg_from_user
+    2,26%  netperf  [sctp]             [k] sctp_sendmsg

Throughput-wise, from 6800mbps without the patch to 7050mbps with it,
~3.7%.

Signed-off-by: Marcelo Ricardo Leitner &lt;marcelo.leitner@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>sctp: flush if we can't fit another DATA chunk</title>
<updated>2016-04-05T19:39:44+00:00</updated>
<author>
<name>Marcelo Ricardo Leitner</name>
<email>marcelo.leitner@gmail.com</email>
</author>
<published>2016-04-01T17:05:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=e43569e6d3c71eb266641c6297ea54f7ac66954f'/>
<id>urn:sha1:e43569e6d3c71eb266641c6297ea54f7ac66954f</id>
<content type='text'>
There is no point on delaying the packet if we can't fit a single byte
of data on it anymore. So lets just reduce the threshold by the amount
that a data chunk with 4 bytes (rounding) would use.

v2: based on the right tree

Signed-off-by: Marcelo Ricardo Leitner &lt;marcelo.leitner@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>sctp: really allow using GFP_KERNEL on sctp_packet_transmit</title>
<updated>2016-03-30T19:41:22+00:00</updated>
<author>
<name>Marcelo Ricardo Leitner</name>
<email>marcelo.leitner@gmail.com</email>
</author>
<published>2016-03-29T13:41:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=28fd34985bd5edaea6282a0586f91bcddd336f5e'/>
<id>urn:sha1:28fd34985bd5edaea6282a0586f91bcddd336f5e</id>
<content type='text'>
Somehow my patch for commit cea8768f333e ("sctp: allow
sctp_transmit_packet and others to use gfp") missed two important
chunks, which are now added.

Fixes: cea8768f333e ("sctp: allow sctp_transmit_packet and others to use gfp")
Signed-off-by: Marcelo Ricardo Leitner &lt;marcelo.leitner@gmail.com&gt;
Acked-By: Neil Horman &lt;nhorman@tuxdriver.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2016-03-24T06:25:14+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-03-24T06:25:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=aca04ce5dbda50758b813b1e3d710098991cfa9a'/>
<id>urn:sha1:aca04ce5dbda50758b813b1e3d710098991cfa9a</id>
<content type='text'>
Pull networking bugfixes from David Miller:
 "Several bug fixes rolling in, some for changes introduced in this
  merge window, and some for problems that have existed for some time:

  1) Fix prepare_to_wait() handling in AF_VSOCK, from Claudio Imbrenda.

  2) The new DST_CACHE should be a silent config option, from Dave
     Jones.

  3) inet_current_timestamp() unintentionally truncates timestamps to
     16-bit, from Deepa Dinamani.

  4) Missing reference to netns in ppp, from Guillaume Nault.

  5) Free memory reference in hv_netvsc driver, from Haiyang Zhang.

  6) Missing kernel doc documentation for function arguments in various
     spots around the networking, from Luis de Bethencourt.

  7) UDP stopped receiving broadcast packets properly, due to
     overzealous multicast checks, fix from Paolo Abeni"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (59 commits)
  net: ping: make ping_v6_sendmsg static
  hv_netvsc: Fix the order of num_sc_offered decrement
  net: Fix typos and whitespace.
  hv_netvsc: Fix the array sizes to be max supported channels
  hv_netvsc: Fix accessing freed memory in netvsc_change_mtu()
  ppp: take reference on channels netns
  net: Reset encap_level to avoid resetting features on inner IP headers
  net: mediatek: fix checking for NULL instead of IS_ERR() in .probe
  net: phy: at803x: Request 'reset' GPIO only for AT8030 PHY
  at803x: fix reset handling
  AF_VSOCK: Shrink the area influenced by prepare_to_wait
  Revert "vsock: Fix blocking ops call in prepare_to_wait"
  macb: fix PHY reset
  ipv4: initialize flowi4_flags before calling fib_lookup()
  fsl/fman: Workaround for Errata A-007273
  ipv4: fix broadcast packets reception
  net: hns: bug fix about the overflow of mss
  net: hns: adds limitation for debug port mtu
  net: hns: fix the bug about mtu setting
  net: hns: fixes a bug of RSS
  ...
</content>
</entry>
<entry>
<title>net/sctp: use in_compat_syscall for sctp_getsockopt_connectx3</title>
<updated>2016-03-22T22:36:02+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@kernel.org</email>
</author>
<published>2016-03-22T21:25:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=96c0e0a908ecfa61118d49db85c03e162b7f6e20'/>
<id>urn:sha1:96c0e0a908ecfa61118d49db85c03e162b7f6e20</id>
<content type='text'>
SCTP unfortunately has a different ABI for SCTP_SOCKOPT_CONNECTX3 for
32-bit and 64-bit callers.  Use in_compat_syscall to correctly
distinguish them on all architectures.

Signed-off-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Vlad Yasevich &lt;vyasevich@gmail.com&gt;
Cc: Neil Horman &lt;nhorman@tuxdriver.com&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>sctp: align MTU to a word</title>
<updated>2016-03-20T20:31:12+00:00</updated>
<author>
<name>Marcelo Ricardo Leitner</name>
<email>marcelo.leitner@gmail.com</email>
</author>
<published>2016-03-19T15:17:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=3822a5ff4bc32043fa9c7b6d6f125bcdca6da39c'/>
<id>urn:sha1:3822a5ff4bc32043fa9c7b6d6f125bcdca6da39c</id>
<content type='text'>
SCTP is a protocol that is aligned to a word (4 bytes). Thus using bare
MTU can sometimes return values that are not aligned, like for loopback,
which is 65536 but ipv4_mtu() limits that to 65535. This mis-alignment
will cause the last non-aligned bytes to never be used and can cause
issues with congestion control.

So it's better to just consider a lower MTU and keep congestion control
calcs saner as they are based on PMTU.

Same applies to icmp frag needed messages, which is also fixed by this
patch.

One other effect of this is the inability to send MTU-sized packet
without queueing or fragmentation and without hitting Nagle. As the
check performed at sctp_packet_can_append_data():

if (chunk-&gt;skb-&gt;len + q-&gt;out_qlen &gt;= transport-&gt;pathmtu - packet-&gt;overhead)
	/* Enough data queued to fill a packet */
	return SCTP_XMIT_OK;

with the above example of MTU, if there are no other messages queued,
one cannot send a packet that just fits one packet (65532 bytes) and
without causing DATA chunk fragmentation or a delay.

v2:
 - Added WORD_TRUNC macro

Signed-off-by: Marcelo Ricardo Leitner &lt;marcelo.leitner@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>sctp: do not leak chunks that are sent to unconfirmed paths</title>
<updated>2016-03-20T20:31:12+00:00</updated>
<author>
<name>Marcelo Ricardo Leitner</name>
<email>marcelo.leitner@gmail.com</email>
</author>
<published>2016-03-18T21:39:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=31b055ef0c6116a27e9a787304ecf87a77d34764'/>
<id>urn:sha1:31b055ef0c6116a27e9a787304ecf87a77d34764</id>
<content type='text'>
Currently, if a chunk is scheduled to be sent through a transport that
is currently unconfirmed, it will be leaked as it is dequeued from outq
and is not re-queued nor freed.

As I'm not aware of any situation that may lead to this situation, I'm
fixing this by freeing the chunk and also logging a trace so that we can
fix the other bug if it ever happens.

Signed-off-by: Marcelo Ricardo Leitner &lt;marcelo.leitner@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>sctp: do not update a_rwnd if we are not issuing a sack</title>
<updated>2016-03-20T20:31:11+00:00</updated>
<author>
<name>Marcelo Ricardo Leitner</name>
<email>marcelo.leitner@gmail.com</email>
</author>
<published>2016-03-18T21:39:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=07b4d6a1749422fa1e054f3c2aba444acdba39e8'/>
<id>urn:sha1:07b4d6a1749422fa1e054f3c2aba444acdba39e8</id>
<content type='text'>
The SACK can be lost pretty much elsewhere, but if its allocation fail,
we know we are not sending it, so it is better to revert a_rwnd to its
previous value as this may give it a chance to issue a window update
later.

Signed-off-by: Marcelo Ricardo Leitner &lt;marcelo.leitner@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux</title>
<updated>2016-03-20T01:05:24+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2016-03-20T01:05:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=c78a85a8430e35aecd53e190a2f6b999062b1037'/>
<id>urn:sha1:c78a85a8430e35aecd53e190a2f6b999062b1037</id>
<content type='text'>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next</title>
<updated>2016-03-19T17:05:34+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-03-19T17:05:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=1200b6809dfd9d73bc4c7db76d288c35fa4b2ebe'/>
<id>urn:sha1:1200b6809dfd9d73bc4c7db76d288c35fa4b2ebe</id>
<content type='text'>
Pull networking updates from David Miller:
 "Highlights:

   1) Support more Realtek wireless chips, from Jes Sorenson.

   2) New BPF types for per-cpu hash and arrap maps, from Alexei
      Starovoitov.

   3) Make several TCP sysctls per-namespace, from Nikolay Borisov.

   4) Allow the use of SO_REUSEPORT in order to do per-thread processing
   of incoming TCP/UDP connections.  The muxing can be done using a
   BPF program which hashes the incoming packet.  From Craig Gallek.

   5) Add a multiplexer for TCP streams, to provide a messaged based
      interface.  BPF programs can be used to determine the message
      boundaries.  From Tom Herbert.

   6) Add 802.1AE MACSEC support, from Sabrina Dubroca.

   7) Avoid factorial complexity when taking down an inetdev interface
      with lots of configured addresses.  We were doing things like
      traversing the entire address less for each address removed, and
      flushing the entire netfilter conntrack table for every address as
      well.

   8) Add and use SKB bulk free infrastructure, from Jesper Brouer.

   9) Allow offloading u32 classifiers to hardware, and implement for
      ixgbe, from John Fastabend.

  10) Allow configuring IRQ coalescing parameters on a per-queue basis,
      from Kan Liang.

  11) Extend ethtool so that larger link mode masks can be supported.
      From David Decotigny.

  12) Introduce devlink, which can be used to configure port link types
      (ethernet vs Infiniband, etc.), port splitting, and switch device
      level attributes as a whole.  From Jiri Pirko.

  13) Hardware offload support for flower classifiers, from Amir Vadai.

  14) Add "Local Checksum Offload".  Basically, for a tunneled packet
      the checksum of the outer header is 'constant' (because with the
      checksum field filled into the inner protocol header, the payload
      of the outer frame checksums to 'zero'), and we can take advantage
      of that in various ways.  From Edward Cree"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1548 commits)
  bonding: fix bond_get_stats()
  net: bcmgenet: fix dma api length mismatch
  net/mlx4_core: Fix backward compatibility on VFs
  phy: mdio-thunder: Fix some Kconfig typos
  lan78xx: add ndo_get_stats64
  lan78xx: handle statistics counter rollover
  RDS: TCP: Remove unused constant
  RDS: TCP: Add sysctl tunables for sndbuf/rcvbuf on rds-tcp socket
  net: smc911x: convert pxa dma to dmaengine
  team: remove duplicate set of flag IFF_MULTICAST
  bonding: remove duplicate set of flag IFF_MULTICAST
  net: fix a comment typo
  ethernet: micrel: fix some error codes
  ip_tunnels, bpf: define IP_TUNNEL_OPTS_MAX and use it
  bpf, dst: add and use dst_tclassid helper
  bpf: make skb-&gt;tc_classid also readable
  net: mvneta: bm: clarify dependencies
  cls_bpf: reset class and reuse major in da
  ldmvsw: Checkpatch sunvnet.c and sunvnet_common.c
  ldmvsw: Add ldmvsw.c driver code
  ...
</content>
</entry>
</feed>
