This patch series introduces an optimization of fragment queues under
load.
The goal is to improve upon the current approach of static timeouts
(frag_timeout, 30 seconds by default) by implementing Eric's
suggestion of reducing timeouts under load [1], with additional
considerations for peer-specific load.
The timeout reduction is done dynamically per peer, based on both
global and peer-specific load. low_thresh is reintroduced and now acts
as a knob for adjusting per-peer memory limits.
A comparison of netperf results before and after applying the patch:
Before:
[vm1 ~]# ./super_netperf.sh 10 -H 172.16.43.3 -l 60 -t UDP_STREAM
103.23
After:
[vm1 ~]# ./super_netperf.sh 10 -H 172.16.43.3 -l 60 -t UDP_STREAM
576.17
And another benchmark of a more specific use case.
One high-bandwidth memory-hogging peer (vm1), and another "average"
client (vm2), attempting to communicate with the same server:
Before:
[vm1 ~]# ./super_netperf.sh 10 -H 172.16.43.3 -l 60 -t UDP_STREAM
42.57
[vm2 ~]# ./super_netperf.sh 1 -H 172.16.43.3 -l 60 -t UDP_STREAM
50.93
After:
[vm1 ~]# ./super_netperf.sh 10 -H 172.16.43.3 -l 60 -t UDP_STREAM
420.65
[vm2 ~]# ./super_netperf.sh 1 -H 172.16.43.3 -l 60 -t UDP_STREAM
624.79
These benchmarks were done using the following configuration:
[vm3 ~]# grep . /proc/sys/net/ipv4/ipfrag_*
/proc/sys/net/ipv4/ipfrag_high_thresh:104857600
/proc/sys/net/ipv4/ipfrag_low_thresh:78643200
/proc/sys/net/ipv4/ipfrag_max_dist:64
/proc/sys/net/ipv4/ipfrag_secret_interval:0
/proc/sys/net/ipv4/ipfrag_time:30
Regards,
Richard
[1] https://www.mail-archive.com/netdev@xxxxxxxxxxxxxxx/msg242228.html
Richard Gobert (4):
net-next: frags: move inetpeer from ip4 to inet
net-next: ip6: fetch inetpeer in ip6frag_init
net-next: frags: add inetpeer frag_mem tracking
net-next: frags: dynamic timeout under load
Documentation/networking/ip-sysctl.rst | 3 +
include/net/inet_frag.h | 13 ++---
include/net/inetpeer.h | 1 +
include/net/ipv6_frag.h | 3 +
net/ieee802154/6lowpan/reassembly.c | 2 +-
net/ipv4/inet_fragment.c | 77 ++++++++++++++++++++++---
net/ipv4/inetpeer.c | 1 +
net/ipv4/ip_fragment.c | 25 ++------
net/ipv6/netfilter/nf_conntrack_reasm.c | 2 +-
net/ipv6/reassembly.c | 2 +-
10 files changed, 89 insertions(+), 40 deletions(-)
--
2.36.1
