K 10
svn:author
V 3
smh
K 8
svn:date
V 27
2017-04-10T08:19:35.518534Z
K 7
svn:log
V 725
Use estimated RTT for receive buffer auto resizing instead of timestamps

Switched from using timestamps to RTT estimates when performing TCP receive
buffer auto resizing, as not all hosts support / enable TCP timestamps.

Disabled reset of receive buffer auto scaling when not in bulk receive mode,
which gives an extra 20% performance increase.

Also extracted auto resizing to a common method shared between standard and
fastpath modules.

With this AWS S3 downloads at ~17ms latency on a 1Gbps connection jump from
~3MB/s to ~100MB/s using the default settings.

Reviewed by:    lstewart, gnn
MFC after:      2 weeks
Relnotes:       Yes
Sponsored by:   Multiplay
Differential Revision:  https://reviews.freebsd.org/D9668

END