[HECnet] Trying to build SIMH from git (on OpenIndiana)

[Mark Pizzolato - Info Comm]

On Wednesday, March 13, 2013 at 12:29 PM, Brian Hechinger wrote:
On 3/13/2013 3:10 PM, Cory Smelosky wrote:


"Solaris timing uses a real-time clock that can generate interrupts at a resolution 
bound by the processor speed. For scheduling purposes, it fires every 10 milliseconds. 
As in Linux, this is a clock "tick." Note that 2.6 Linux uses a 1000-tick/second clock, as 
opposed to the 100-tick/second clock used by Solaris and by previous versions of 
Linux. User-level programs on Solaris can program the real time clock to fire at 
nanosecond granularity, rounded up by processor time--much finer than the clock 
tick granularity of ten or one milliseconds. However, the program interface to use 
the high-resolution timers is not visible in the DDI/DKI. See  clock_settime(3rt)  for 
user-level details andusr/src/uts/common/os/cyclic.c  for details on high-resolution 
timing in Solaris.

Also note that in Solaris, you can change the value of  hz  or clock ticks/second by 
setting  hires_tick  to 1 and  hires_hz  to the desired time in the  /etc/system  file. 
The default is 1000 ticks per second. Here's an example:

set hires_tick=1
set hires_hz=10000 <~--- 10000 ticks per second"

Looks like Solaris can set it in user mode, too.

Are you going to take a stab at this, Mark? If not, I will.

I don't have a platform to test on, so I'd suggest that you first try messing with the values in /etc/system and if that gets things working, then I'll add it to the FAQ.   If it doesn't then messing with the mentioned APIs can be explored.   Since the size of the system clock tick is system wide, you can explore this without making any changes to the simh code.   Write s simple program which tries to set the tick to 1ms and then sleeps until it is interrupted.   While running this program start simh and see what it thinks about idling....

- Mark