Linux Tuning

Data about kernel tuning will be collected here.

Network tuning

To allow receive of multicast packets it is necessary to set route rules for multicast:

# route add -net 224.0.0.0 netmask 240.0.0.0 dev eth0

To avoid packet lossing it is necessary to increase a size of socket receive buffer to 1500000 bytes (tested with ElphelOgm on Intel(R) Pentium(R) 4 CPU 3.20GHz with 100Mbit ethernet card and multicast flow from the camera about 6MB/s).

# echo 1500000 > /proc/sys/net/core/rmem_max
# echo 1500000 > /proc/sys/net/core/rmem_default

Virtual memory subsystem tuning

For Linux version 2.4.

# echo 30 10 0 0 4 3000 70 0 0 > /proc/sys/vm/bdflush

For Linux version 2.6.

# echo 5 > /proc/sys/vm/dirty_background_ratio
# echo 70 > /proc/sys/vm/dirty_ratio
# echo 4 > /proc/sys/vm/dirty_writeback_centisecs
# echo 3000 > /proc/sys/vm/dirty_expire_centisecs

Links

Old discussions on SourceForge

Linux Tuning Guide (for 2.4 kernels)

Red Hat Enterprise Linux 4: Reference Guide: Directories within /proc/