////////////////////////////////////////// //// WHAT I NEED TO DO? ///////////////////////////////////////// brc: http://vserver.13thfloor.at/Experimental/patch-2.6.9-varhz.diff this patch will allow you to change your timer frequency reboot is called with an option that causes all network interfaces to be shut down brc: between 100 and 20000 Hz the default is at 1000 Hz man reboot: -i Shut down all network interfaces just before halt or reboot. brc: it would be intersting to test at least the following values: 100, 20000, 10000, 5000, 500 (in this order) brc: it might be that a kernel with a specific setting doesn't even boot, although I hope it works fine brc: interesting would be to observe the uptime and /proc/interrupts and check for example if sleep 60 really pauses for 60 seconds herbert@13thfloor.at ////////////////////////////////////////// //// HOW IT WAS TESTED ///////////////////////////////////////// ssh root@192.168.7.30 cat /proc/interrupts ssh root@192.168.7.30 uptime date ; ssh root@192.168.7.30 sleep 60 ;date ////////////////////////////////////////// //// "NORMAL" kernel returned ///////////////////////////////////////// bruce@linux:~$ ssh root@192.168.7.30 cat /proc/interrupts CPU0 0: 4325 XT-PIC timer 1: 52 XT-PIC keyboard 2: 0 XT-PIC cascade 8: 3 XT-PIC rtc 9: 0 XT-PIC usb-uhci 10: 0 XT-PIC es1371 11: 53 XT-PIC PCnet/PCI II 79C970A 14: 5286 XT-PIC ide0 15: 3 XT-PIC ide1 NMI: 0 ERR: 0 bruce@linux:~$ ssh root@192.168.7.30 uptime 20:00:28 up 0 min, 1 user, load average: 0.14, 0.04, 0.01 bruce@linux:~$ date ; ssh root@192.168.7.30 sleep 60 ;date Sat Nov 20 20:00:48 BRST 2004 Sat Nov 20 20:01:53 BRST 2004 bruce@linux:~$ ////////////////////////////////////////// //// FREQUENCY 100 ///////////////////////////////////////// bruce@linux:~$ ssh root@192.168.7.30 cat /proc/interrupts CPU0 0: 14734 XT-PIC timer 1: 580 XT-PIC i8042 2: 0 XT-PIC cascade 8: 3 XT-PIC rtc 9: 0 XT-PIC acpi 11: 60 XT-PIC eth0 14: 1896 XT-PIC ide0 15: 11 XT-PIC ide1 NMI: 0 ERR: 0 bruce@linux:~$ ssh root@192.168.7.30 uptime 19:41:31 up 2 min, 1 user, load average: 0.05, 0.06, 0.02 bruce@linux:~$ date ; ssh root@192.168.7.30 sleep 60 ;date Sat Nov 20 19:42:05 BRST 2004 Sat Nov 20 19:43:11 BRST 2004 ////////////////////////////////////////// //// FREQUENCY 20000 ///////////////////////////////////////// bruce@linux:~$ ssh root@192.168.7.30 cat /proc/interrupts CPU0 0: 572461 XT-PIC timer 1: 233 XT-PIC i8042 2: 0 XT-PIC cascade 8: 3 XT-PIC rtc 9: 0 XT-PIC acpi 11: 31 XT-PIC eth0 14: 1488 XT-PIC ide0 15: 11 XT-PIC ide1 NMI: 0 ERR: 0 bruce@linux:~$ ssh root@192.168.7.30 uptime Unknown HZ value! (93) Assume 100. 19:44:16 up 0 min, 1 user, load average: 0.11, 0.03, 0.01 bruce@linux:~$ date ; ssh root@192.168.7.30 sleep 60 ;date Sat Nov 20 19:45:35 BRST 2004 Sat Nov 20 19:48:08 BRST 2004 bruce@linux:~$ ////////////////////////////////////////// //// FREQUENCY 10000 ///////////////////////////////////////// bruce@linux:~$ ssh root@192.168.7.30 cat /proc/interrupts CPU0 0: 277860 XT-PIC timer 1: 226 XT-PIC i8042 2: 0 XT-PIC cascade 8: 3 XT-PIC rtc 9: 0 XT-PIC acpi 11: 28 XT-PIC eth0 14: 1439 XT-PIC ide0 15: 11 XT-PIC ide1 NMI: 0 ERR: 0 bruce@linux:~$ ssh root@192.168.7.30 uptime 19:47:15 up 0 min, 1 user, load average: 0.24, 0.06, 0.02 bruce@linux:~$ date ; ssh root@192.168.7.30 sleep 60 ;date Sat Nov 20 19:51:32 BRST 2004 Sat Nov 20 19:52:56 BRST 2004 bruce@linux:~$ ////////////////////////////////////////// //// FREQUENCY 5000 ///////////////////////////////////////// bruce@linux:~$ ssh root@192.168.7.30 cat /proc/interrupts CPU0 0: 274532 XT-PIC timer 1: 252 XT-PIC i8042 2: 0 XT-PIC cascade 8: 3 XT-PIC rtc 9: 0 XT-PIC acpi 11: 29 XT-PIC eth0 14: 13165 XT-PIC ide0 15: 11 XT-PIC ide1 NMI: 0 ERR: 0 bruce@linux:~$ ssh root@192.168.7.30 uptime Unknown HZ value! (47) Assume 100. 19:50:17 up 0 min, 1 user, load average: 0.59, 0.18, 0.06 bruce@linux:~$ date ; ssh root@192.168.7.30 sleep 60 ;date Sat Nov 20 19:55:14 BRST 2004 Sat Nov 20 19:56:34 BRST 2004 bruce@linux:~$ ////////////////////////////////////////// //// FREQUENCY 500 ///////////////////////////////////////// bruce@linux:~$ ssh root@192.168.7.30 cat /proc/interrupts CPU0 0: 12954 XT-PIC timer 1: 176 XT-PIC i8042 2: 0 XT-PIC cascade 8: 3 XT-PIC rtc 9: 0 XT-PIC acpi 11: 27 XT-PIC eth0 14: 1433 XT-PIC ide0 15: 11 XT-PIC ide1 NMI: 0 ERR: 0 bruce@linux:~$ ssh root@192.168.7.30 uptime 19:52:22 up 0 min, 1 user, load average: 0.06, 0.01, 0.00 Unknown HZ value! (91) Assume 100. bruce@linux:~$ date ; ssh root@192.168.7.30 sleep 60 ;date Sat Nov 20 19:57:50 BRST 2004 Sat Nov 20 19:59:15 BRST 2004 bruce@linux:~$