ChorusOS 5.0 Transition Guide

New Tunables and Their Default Settings

The following table lists the tunables that are new in version 5.0 of the ChorusOS operating system, along with their default settings.

Table 4-3 New ChorusOS Tunables

Tunable 

Description 

Default Setting 

kern.mkstat.maxevents

Maximum number of MKSTAT events

1024 

kern.systemdump.systemdumpSize

System dump memory area size 

0x20000 

kern.blackbox.maxBufferNumber

Maximum number of circular buffers 

kern.blackbox.bufsize

Size of each blackbox circular buffer (in Kb)

64 

kern.blackbox.maxFilterNumber

Maximum fine-grained filters 

64 

kern.blackbox.maxProcIdNumber

Maximum proc ID filters 

64 

kern.blackbox.kernelLogging

Microkernel logging messages 

iom.persistentramdisk0

Current size of persistent ramdisk 0 

iom.persistentramdisk1

Current size of persistent ramdisk 

iom.persistentramdisk2

Current size of persistent ramdisk 2 

iom.persistentramdisk3

Current size of persistent ramdisk 3 

iom.persistentramdisk4

Current size of persistent ramdisk 4 

iom.persistentramdisk5

Current size of persistent ramdisk 5 

iom.persistentramdisk6

Current size of persistent ramdisk 6 

iom.persistentramdisk7

Current size of persistent ramdisk 7 

iom.persistentramdisk8

Current size of persistent ramdisk 8 

iom.persistentramdisk9

Current size of persistent ramdisk 9 

iom.persistentramdiska

Current size of persistent ramdisk 10 

iom.persistentramdiskb

Current size of persistent ramdisk 11 

iom.persistentramdiskc

Current size of persistent ramdisk 12 

iom.persistentramdiskd

Current size of persistent ramdisk 13 

iom.persistentramdiske

Current size of persistent ramdisk 14 

iom.persistentramdiskf

Current size of persistent ramdisk 15 

iom.wdt.defer

Defer watchdog interrupt processing to C_OS interrupt thread 

iom.wdt.sysdump

watchdog triggering system dump 

iom.wdt.period

Internal period (in ms) of the watchdog timer 

4000 

iom.wdt.slack

Slack time (in ms) of the internal timeout handler 

4000 

iom.wdt.action

Execution time (in ms) of the action taken by the watchdog interrupt handler 

2000 

iom.wdt.maxInterval

Maximum timeout interval (in ms) allowed by the watchdog timer API  

180000 

iom.wdt.startupInterval

Maximum time (in ms) required for the startup sequence to complete 

iom.wdt.shutdownInterval

Maximum time (in ms) required for the shutdown sequence to complete 

iom.os_gauges.activestart

OS_GAUGES signaling sysevents actived at C_OS init 

iom.os_gauges.syslog

OS_GAUGES sysevents errors in syslog messages 

iom.bootverbose

C_OS Activate boot verbose mode 

iom.nprocs

C_OS maximum number of processes 

64 

iom.nthreadsperproc

C_OS maximum number of threads per process 

64 

iom.nprocsperuid

C_OS maximum number of processes per user 

63 

iom.maxcoresize

C_OS maximum permitted size of a core file 

2100000 

iom.maxsockets

C_OS maximum number of open sockets 

64 

iom.nmbufs

C_OS maximum number of open sockets 

2048 

iom.userstacksize

Default stack size of user mode threads 

0x8000 

cgtp.filter_tab_nb

CGTP number of filter tables 

40 

cgtp.sub_tab_nb

CGTP number of subtables in filter tables 

cgtp.entry_nb

CGTP number of entries per subtable 

[2, 4096] by power of 2 

cgtp.elem_nb

CGTP number of elements per entry 

cgtp.resolution

Definition of CGTP filter period 

iom.ipv6.gif.number

Number of GIF interfaces 

iom.inet.use_hw_checksum

Mask controlling the use of hardware checksum capability by the networking stack 

0x001 -- IP header checksum 

0x002 -- TCP header checksum 

0x004 -- UDP header checksum 

0x008 -- checksum over IP fragments 

0x010 -- hardware fragments IP packets 

0x100 -- IP header checksum verified on reception 

0x200 -- IP header checksum is valid 

0x400 -- data checksum computed on reception 

0x800 -- data checksum computed with TCP/UDP pseudo headers 

0xffff 

iom.rtsig.sigqueuemax

Maximum number of signals that can be queued per process 

32 

sysdump.device

Device number used to process the TFTP transfer