SUNOS: Samba grabs all semaphores

[Andrew Miller]

Ole,

Semaphores are a very cheap system resource in SunOS 4.1.x.  You can easily
bump up the max number using adb, without even recompiling the kernel.


_seminfo:
_seminfo+0      semmap  30
_seminfo+4      semmni  256
_seminfo+8      semmns  1024
_seminfo+0xc    semmnu  1024
_seminfo+0x10   semmsl  1024
_seminfo+0x14   semopm  100
_seminfo+0x18   semume  256
_seminfo+0x1c   semusz  2064
_seminfo+0x20   semvmx  32767
_seminfo+0x24   semaem  16384


To set "semmns" and other parameters without recompiling the kernel, do
somthing
like;

# /bin/adb -w -k /vmunix /dev/mem <<EOF
_seminfo+8?D
_seminfo+8?W 0x400
EOF
# reboot

The first line prints what the current value is, the second sets it to 1024.
You have to reboot for the changes to take effect.

I've also got an adb program to dump all the ipc parameters.  Very handy.
I can send it via private mail. (in return for some .dk culinary token).

Good Luck,


- Andrew -
-------------- next part --------------
#!/bin/sh
#
# Print kernel IPC structures.		AGM 4/97
#
/bin/adb -k /vmunix /dev/mem << EOF
version,(utsname-version)?c
msginfo?n"msgmap"8t1Dn"msgmax"8t1Dn"msgmnb"8t1Dn"msgssz"8t1Dn"msgtql"8t1Dn"msgseg"8t1dnn
seminfo?n"semmap"8t1Dn"semmni"8t1Dn"semmns"8t1Dn"semmnu"8t1Dn"semmsl"8t1Dn"semopm"8t1Dn"semume"8t1Dn"semusz"8t1Dn"semvmx"8t1Dn"semaem"8t1Dnn
shminfo?n"shmmax"8t1Dn"shmmin"8t1Dn"shmmni"8t1Dnn
EOF