<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel.git/net/ipv4/af_inet.c, branch linux-2.6.36.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.
</subtitle>
<id>https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-2.6.36.y</id>
<link rel='self' href='https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-2.6.36.y'/>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/'/>
<updated>2010-07-13T03:21:46Z</updated>
<entry>
<title>inet, inet6: make tcp_sendmsg() and tcp_sendpage() through inet_sendmsg() and inet_sendpage()</title>
<updated>2010-07-13T03:21:46Z</updated>
<author>
<name>Changli Gao</name>
</author>
<published>2010-07-10T20:41:55Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=7ba42910073f8432934d61a6c08b1023c408fb62'/>
<id>urn:sha1:7ba42910073f8432934d61a6c08b1023c408fb62</id>
<content type='text'>
a new boolean flag no_autobind is added to structure proto to avoid the autobind
calls when the protocol is TCP. Then sock_rps_record_flow() is called int the
TCP's sendmsg() and sendpage() pathes.

Signed-off-by: Changli Gao &lt;xiaosuo@gmail.com&gt;
----
 include/net/inet_common.h |    4 ++++
 include/net/sock.h        |    1 +
 include/net/tcp.h         |    8 ++++----
 net/ipv4/af_inet.c        |   15 +++++++++------
 net/ipv4/tcp.c            |   11 +++++------
 net/ipv4/tcp_ipv4.c       |    3 +++
 net/ipv6/af_inet6.c       |    8 ++++----
 net/ipv6/tcp_ipv6.c       |    3 +++
 8 files changed, 33 insertions(+), 20 deletions(-)
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>snmp: 64bit ipstats_mib for all arches</title>
<updated>2010-06-30T20:31:19Z</updated>
<author>
<name>Eric Dumazet</name>
</author>
<published>2010-06-30T20:31:19Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=4ce3c183fcade7f4b30a33dae90cd774c3d9e094'/>
<id>urn:sha1:4ce3c183fcade7f4b30a33dae90cd774c3d9e094</id>
<content type='text'>
/proc/net/snmp and /proc/net/netstat expose SNMP counters.

Width of these counters is either 32 or 64 bits, depending on the size
of "unsigned long" in kernel.

This means user program parsing these files must already be prepared to
deal with 64bit values, regardless of user program being 32 or 64 bit.

This patch introduces 64bit snmp values for IPSTAT mib, where some
counters can wrap pretty fast if they are 32bit wide.

# netstat -s|egrep "InOctets|OutOctets"
    InOctets: 244068329096
    OutOctets: 244069348848

Signed-off-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>snmp: add align parameter to snmp_mib_init()</title>
<updated>2010-06-26T04:33:17Z</updated>
<author>
<name>Eric Dumazet</name>
</author>
<published>2010-06-22T20:58:41Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=1823e4c80eeae2a774c75569ce3035070e5ee009'/>
<id>urn:sha1:1823e4c80eeae2a774c75569ce3035070e5ee009</id>
<content type='text'>
In preparation for 64bit snmp counters for some mibs,
add an 'align' parameter to snmp_mib_init(), instead
of assuming mibs only contain 'unsigned long' fields.

Callers can use __alignof__(type) to provide correct
alignment.

Signed-off-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
CC: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
CC: Arnaldo Carvalho de Melo &lt;acme@ghostprotocols.net&gt;
CC: Hideaki YOSHIFUJI &lt;yoshfuji@linux-ipv6.org&gt;
CC: Vlad Yasevich &lt;vladislav.yasevich@hp.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net - IP_NODEFRAG option for IPv4 socket</title>
<updated>2010-06-23T20:16:38Z</updated>
<author>
<name>Jiri Olsa</name>
</author>
<published>2010-06-15T01:07:31Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=7b2ff18ee7b0ec4bc3162f821e221781aaca48bd'/>
<id>urn:sha1:7b2ff18ee7b0ec4bc3162f821e221781aaca48bd</id>
<content type='text'>
this patch is implementing IP_NODEFRAG option for IPv4 socket.
The reason is, there's no other way to send out the packet with user
customized header of the reassembly part.

Signed-off-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net-next: remove useless union keyword</title>
<updated>2010-06-11T06:31:35Z</updated>
<author>
<name>Changli Gao</name>
</author>
<published>2010-06-11T06:31:35Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=d8d1f30b95a635dbd610dcc5eb641aca8f4768cf'/>
<id>urn:sha1:d8d1f30b95a635dbd610dcc5eb641aca8f4768cf</id>
<content type='text'>
remove useless union keyword in rtable, rt6_info and dn_route.

Since there is only one member in a union, the union keyword isn't useful.

Signed-off-by: Changli Gao &lt;xiaosuo@gmail.com&gt;
Signed-off-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: reserve ports for applications using fixed port numbers</title>
<updated>2010-05-16T06:28:40Z</updated>
<author>
<name>Amerigo Wang</name>
</author>
<published>2010-05-05T00:27:06Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=e3826f1e946e7d2354943232f1457be1455a29e2'/>
<id>urn:sha1:e3826f1e946e7d2354943232f1457be1455a29e2</id>
<content type='text'>
(Dropped the infiniband part, because Tetsuo modified the related code,
I will send a separate patch for it once this is accepted.)

This patch introduces /proc/sys/net/ipv4/ip_local_reserved_ports which
allows users to reserve ports for third-party applications.

The reserved ports will not be used by automatic port assignments
(e.g. when calling connect() or bind() with port number 0). Explicit
port allocation behavior is unchanged.

Signed-off-by: Octavian Purdila &lt;opurdila@ixiacom.com&gt;
Signed-off-by: WANG Cong &lt;amwang@redhat.com&gt;
Cc: Neil Horman &lt;nhorman@tuxdriver.com&gt;
Cc: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Cc: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: Make RFS socket operations not be inet specific.</title>
<updated>2010-04-27T22:11:48Z</updated>
<author>
<name>David S. Miller</name>
</author>
<published>2010-04-27T22:05:31Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=c58dc01babfd58ec9e71a6ce080150dc27755d88'/>
<id>urn:sha1:c58dc01babfd58ec9e71a6ce080150dc27755d88</id>
<content type='text'>
Idea from Eric Dumazet.

As for placement inside of struct sock, I tried to choose a place
that otherwise has a 32-bit hole on 64-bit systems.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Acked-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
</content>
</entry>
<entry>
<title>net: Fix various endianness glitches</title>
<updated>2010-04-21T02:06:52Z</updated>
<author>
<name>Eric Dumazet</name>
</author>
<published>2010-04-21T02:06:52Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=0eae88f31ca2b88911ce843452054139e028771f'/>
<id>urn:sha1:0eae88f31ca2b88911ce843452054139e028771f</id>
<content type='text'>
Sparse can help us find endianness bugs, but we need to make some
cleanups to be able to more easily spot real bugs.

Signed-off-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: sk_sleep() helper</title>
<updated>2010-04-20T23:37:13Z</updated>
<author>
<name>Eric Dumazet</name>
</author>
<published>2010-04-20T13:03:51Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=aa395145165cb06a0d0885221bbe0ce4a564391d'/>
<id>urn:sha1:aa395145165cb06a0d0885221bbe0ce4a564391d</id>
<content type='text'>
Define a new function to return the waitqueue of a "struct sock".

static inline wait_queue_head_t *sk_sleep(struct sock *sk)
{
	return sk-&gt;sk_sleep;
}

Change all read occurrences of sk_sleep by a call to this function.

Needed for a future RCU conversion. sk_sleep wont be a field directly
available.

Signed-off-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>rfs: Receive Flow Steering</title>
<updated>2010-04-16T23:01:27Z</updated>
<author>
<name>Tom Herbert</name>
</author>
<published>2010-04-16T23:01:27Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=fec5e652e58fa6017b2c9e06466cb2a6538de5b4'/>
<id>urn:sha1:fec5e652e58fa6017b2c9e06466cb2a6538de5b4</id>
<content type='text'>
This patch implements receive flow steering (RFS).  RFS steers
received packets for layer 3 and 4 processing to the CPU where
the application for the corresponding flow is running.  RFS is an
extension of Receive Packet Steering (RPS).

The basic idea of RFS is that when an application calls recvmsg
(or sendmsg) the application's running CPU is stored in a hash
table that is indexed by the connection's rxhash which is stored in
the socket structure.  The rxhash is passed in skb's received on
the connection from netif_receive_skb.  For each received packet,
the associated rxhash is used to look up the CPU in the hash table,
if a valid CPU is set then the packet is steered to that CPU using
the RPS mechanisms.

The convolution of the simple approach is that it would potentially
allow OOO packets.  If threads are thrashing around CPUs or multiple
threads are trying to read from the same sockets, a quickly changing
CPU value in the hash table could cause rampant OOO packets--
we consider this a non-starter.

To avoid OOO packets, this solution implements two types of hash
tables: rps_sock_flow_table and rps_dev_flow_table.

rps_sock_table is a global hash table.  Each entry is just a CPU
number and it is populated in recvmsg and sendmsg as described above.
This table contains the "desired" CPUs for flows.

rps_dev_flow_table is specific to each device queue.  Each entry
contains a CPU and a tail queue counter.  The CPU is the "current"
CPU for a matching flow.  The tail queue counter holds the value
of a tail queue counter for the associated CPU's backlog queue at
the time of last enqueue for a flow matching the entry.

Each backlog queue has a queue head counter which is incremented
on dequeue, and so a queue tail counter is computed as queue head
count + queue length.  When a packet is enqueued on a backlog queue,
the current value of the queue tail counter is saved in the hash
entry of the rps_dev_flow_table.

And now the trick: when selecting the CPU for RPS (get_rps_cpu)
the rps_sock_flow table and the rps_dev_flow table for the RX queue
are consulted.  When the desired CPU for the flow (found in the
rps_sock_flow table) does not match the current CPU (found in the
rps_dev_flow table), the current CPU is changed to the desired CPU
if one of the following is true:

- The current CPU is unset (equal to RPS_NO_CPU)
- Current CPU is offline
- The current CPU's queue head counter &gt;= queue tail counter in the
rps_dev_flow table.  This checks if the queue tail has advanced
beyond the last packet that was enqueued using this table entry.
This guarantees that all packets queued using this entry have been
dequeued, thus preserving in order delivery.

Making each queue have its own rps_dev_flow table has two advantages:
1) the tail queue counters will be written on each receive, so
keeping the table local to interrupting CPU s good for locality.  2)
this allows lockless access to the table-- the CPU number and queue
tail counter need to be accessed together under mutual exclusion
from netif_receive_skb, we assume that this is only called from
device napi_poll which is non-reentrant.

This patch implements RFS for TCP and connected UDP sockets.
It should be usable for other flow oriented protocols.

There are two configuration parameters for RFS.  The
"rps_flow_entries" kernel init parameter sets the number of
entries in the rps_sock_flow_table, the per rxqueue sysfs entry
"rps_flow_cnt" contains the number of entries in the rps_dev_flow
table for the rxqueue.  Both are rounded to power of two.

The obvious benefit of RFS (over just RPS) is that it achieves
CPU locality between the receive processing for a flow and the
applications processing; this can result in increased performance
(higher pps, lower latency).

The benefits of RFS are dependent on cache hierarchy, application
load, and other factors.  On simple benchmarks, we don't necessarily
see improvement and sometimes see degradation.  However, for more
complex benchmarks and for applications where cache pressure is
much higher this technique seems to perform very well.

Below are some benchmark results which show the potential benfit of
this patch.  The netperf test has 500 instances of netperf TCP_RR
test with 1 byte req. and resp.  The RPC test is an request/response
test similar in structure to netperf RR test ith 100 threads on
each host, but does more work in userspace that netperf.

e1000e on 8 core Intel
   No RFS or RPS		104K tps at 30% CPU
   No RFS (best RPS config):    290K tps at 63% CPU
   RFS				303K tps at 61% CPU

RPC test	tps	CPU%	50/90/99% usec latency	Latency StdDev
  No RFS/RPS	103K	48%	757/900/3185		4472.35
  RPS only:	174K	73%	415/993/2468		491.66
  RFS		223K	73%	379/651/1382		315.61

Signed-off-by: Tom Herbert &lt;therbert@google.com&gt;
Signed-off-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
</feed>
