Commit Graph

12 Commits

Author SHA1 Message Date
Navdeep Parhar
7127e6acf0 Merge r254336 from user/np/cxl_tuning.
Add a last-modified timestamp to each LRO entry and provide an interface
to flush all inactive entries.  Drivers decide when to flush and what
the inactivity threshold should be.

Network drivers that process an rx queue to completion can enter a
livelock type situation when the rate at which packets are received
reaches equilibrium with the rate at which the rx thread is processing
them.  When this happens the final LRO flush (normally when the rx
routine is done) does not occur.  Pure ACKs and segments with total
payload < 64K can get stuck in an LRO entry.  Symptoms are that TCP
tx-mostly connections' performance falls off a cliff during heavy,
unrelated rx on the interface.

Flushing only inactive LRO entries works better than any of these
alternates that I tried:
- don't LRO pure ACKs
- flush _all_ LRO entries periodically (every 'x' microseconds or every
  'y' descriptors)
- stop rx processing in the driver periodically and schedule remaining
  work for later.

Reviewed by:	andre
2013-08-28 23:00:34 +00:00
Andrew Gallatin
e5ca1ffab5 Fix tcp_lro_rx_ipv4() for drivers that do not set CSUM_IP_CHECKED.
Specifcially, in_cksum_hdr() returns 0 (not 0xffff) when the IPv4
checksum is correct. Without this fix, the tcp_lro code will reject
good IPv4 traffic from drivers that do not implement IPv4 header
harder csum offload.

Sponsored by: Myricom Inc.

MFC after:	7 days
2013-02-21 17:00:35 +00:00
Bjoern A. Zeeb
5fa2656e55 Make TCP LRO work properly with VIMAGE kernels rather than just panicing.
There's no VIMAGE context set there yet as this is before if_ethersubr.c.

MFC after:	3 days
X-MFC with:	r235981
2012-06-01 11:42:50 +00:00
Bjoern A. Zeeb
cace7064fc Trim the extra $FreeBSD$ from the comment below the license. We use
the __FBSDID() macro on the file now instead.

MFC after:	3 days
2012-05-26 10:28:11 +00:00
Bjoern A. Zeeb
31bfc56ecd In case forwarding is turned on for a given address family, refuse to
queue the packet for LRO and tell the driver to directly pass it on.
This avoids re-assembly and later re-fragmentation problems when
forwarding.

It's not the best solution but the simplest and most effective for
the moment.

Should have been done:	ages ago
Discussed with and by:	many
MFC after:		3 days
2012-05-25 08:17:59 +00:00
Bjoern A. Zeeb
62b5b6ecd0 MFp4 bz_ipv6_fast:
Significantly update tcp_lro for mostly two things:
  1) introduce basic support for IPv6 without extension headers.
  2) try hard to also get the incremental checksum updates right,
     especially also in the IPv4 case for the IP and TCP header.

  Move variables around for better locality, factor things out into
  functions, allow checksum updates to be compiled out, ...

  Leave a few comments on further things to look at in the future,
  though that is not the full list.

  Update drivers with appropriate #includes as needed for IPv6 data
  type in LRO.

  Sponsored by:	The FreeBSD Foundation
  Sponsored by:	iXsystems

Reviewed by:	gnn (as part of the whole)
MFC After:	3 days
2012-05-24 23:03:23 +00:00
Bjoern A. Zeeb
27f190a3ca Switch to a standard 2 clause BSD license (from bsd-style-copyright).
Approved by:	Myricom Inc. (gallatin)
Approved by:	Intel Corporation (jfv)
2012-05-15 13:23:44 +00:00
Colin Percival
ca7122622b Don't allow lro->len to exceed 65535, as this will result in overflow
when len is inserted back into the synthetic IP packet and cause a
multiple of 2^16 bytes of TCP "packet loss".

This improves Linux->FreeBSD netperf bandwidth by a factor of 300 in
testing on Amazon EC2.

Reviewed by:	jfv
MFC after:	2 weeks
2011-07-05 18:43:54 +00:00
Jack F Vogel
c31aa19c53 Port of the LRO fix from mxge driver to the generic
LRO code. Thanks to Andrew Gallatin for the change.

MFC after:  7 days
2011-04-07 21:20:26 +00:00
John Baldwin
79e955ed63 Trim extra spaces before tabs. 2011-01-07 21:40:34 +00:00
Kip Macy
4570959392 Don't calculate checksum if it has already been validated
Obtained from:	Chelsio Inc.
MFC after:	3 days
2008-08-24 02:31:09 +00:00
Jack F Vogel
6c5087a818 Add generic TCP LOR into netinet 2008-06-11 22:12:50 +00:00