[Asterisk-Dev] MeetMe with SMP and no USB

[Tilghman Lesher]

On Thursday 09 September 2004 06:47, Gilad Ben-Yossef wrote:
> Moaning and complaining aside :-) I know (because I've done and it
> works) that one can easily change the definition of HZ macro of the
> Linux kernel (param.h) from it's default of 100 (on x86) to 1000, thus
> setting regular timer tick of Linux to 1000Hz.
>
> In fact, in 2.6 I believe that 1000 is even the default value as well as
> being the defult value on PPC and Alpha.

In 2.6, the default for i386 is still 100, although the location of the
definition seems to be <asm/param.h>.  PPC default is also 100.  Alpha
default seems to be either 1024 or 1200, depending upon the hardware.

> So, assuming the regular timer tick of the system is of 1000Hz, does an
> outside timing source is really required?

The problem is that this software tick is approximate and does not provide
the rigid 1/1000 tick that is needed.  Each sample would therefore not always
be the same length (some short of 1/1000th, some longer than that period), so
your audio would be imperfect.  How imperfect it would be would depend upon
the actual system hardware and the current system load.

-- 
Tilghman