d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Clarify the comments related to DUMMYNET and HZ

Browse Source 
MFC after: 3 days
This commit is contained in:
luigi 2001-12-14 23:25:58 +00:00
parent 656205c800
commit 2591be5c9f
2 changed files with 24 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
sys/conf/NOTES
View File

@ -638,9 +638,13 @@ options ACCEPT_FILTER_HTTP
options TCP_DROP_SYNFIN #drop TCP packets with SYN+FIN
# DUMMYNET enables the "dummynet" bandwidth limiter. You need
# IPFIREWALL as well. See the dummynet(4) manpage for more info.
# IPFIREWALL as well. See the dummynet(4) and ipfw(8) manpages for more info.
# When you run DUMMYNET it is advisable to also have "options HZ=1000"
# to achieve a smoother scheduling of the traffic.
#
# BRIDGE enables bridging between ethernet cards -- see bridge(4).
# You can use IPFIREWALL and dummynet together with bridging.
# You can use IPFIREWALL and DUMMYNET together with bridging.
#
options DUMMYNET
options BRIDGE
@ -832,11 +836,12 @@ options _KPOSIX_VERSION=199309L
# CLOCK OPTIONS
# The granularity of operation is controlled by the kernel option HZ whose
# default value (100) means a granularity of 10ms. For an accurate simulation
# of high data rates it might be necessary to reduce the timer granularity to
# 1ms or less. Consider, however, that some interfaces using programmed I/O
# may require a considerable time to output packets. So, reducing the
# granularity too much might actually cause ticks to be missed thus reducing
# default value (100) means a granularity of 10ms (1s/HZ).
# Some subsystems, such as DUMMYNET, might benefit from a smaller
# granularity such as 1ms or less, for a smoother scheduling of packets.
# Consider, however, that reducing the granularity too much might
# cause excessive overhead in clock interrupt processing,
# potentially causing ticks to be missed and thus actually reducing
# the accuracy of operation.
options HZ=100

19
sys/i386/conf/NOTES
View File

@ -638,9 +638,13 @@ options ACCEPT_FILTER_HTTP
options TCP_DROP_SYNFIN #drop TCP packets with SYN+FIN
# DUMMYNET enables the "dummynet" bandwidth limiter. You need
# IPFIREWALL as well. See the dummynet(4) manpage for more info.
# IPFIREWALL as well. See the dummynet(4) and ipfw(8) manpages for more info.
# When you run DUMMYNET it is advisable to also have "options HZ=1000"
# to achieve a smoother scheduling of the traffic.
#
# BRIDGE enables bridging between ethernet cards -- see bridge(4).
# You can use IPFIREWALL and dummynet together with bridging.
# You can use IPFIREWALL and DUMMYNET together with bridging.
#
options DUMMYNET
options BRIDGE
@ -832,11 +836,12 @@ options _KPOSIX_VERSION=199309L
# CLOCK OPTIONS
# The granularity of operation is controlled by the kernel option HZ whose
# default value (100) means a granularity of 10ms. For an accurate simulation
# of high data rates it might be necessary to reduce the timer granularity to
# 1ms or less. Consider, however, that some interfaces using programmed I/O
# may require a considerable time to output packets. So, reducing the
# granularity too much might actually cause ticks to be missed thus reducing
# default value (100) means a granularity of 10ms (1s/HZ).
# Some subsystems, such as DUMMYNET, might benefit from a smaller
# granularity such as 1ms or less, for a smoother scheduling of packets.
# Consider, however, that reducing the granularity too much might
# cause excessive overhead in clock interrupt processing,
# potentially causing ticks to be missed and thus actually reducing
# the accuracy of operation.
options HZ=100