[Asterisk-Dev] High resolution timers using POSIX clocks instead of zaptel

[Steve Kann]

Steven wrote:

>On Tue, 2005-06-07 at 12:16 -0400, Steve Kann wrote:
>  
>
>>Gilad Ben-Yossef wrote:
>>
>>    
>>
>>>Derek Smithies wrote:
>>>
>>>      
>>>
>>>>Does anyone have some realworld experience on a recent machine & 
>>>>software timers to prove they are still a bad idea?
>>>>
>>>>        
>>>>
>>>Fact of life - on a 2.4 Linux kernel for x86 or PPC the timer 
>>>resolution is 10ms (look for the HZ macro in 
>>>/usr/src/linux/include/asm/param.h) That's simply not enough.
>>>      
>>>
>>Not enough for what?  What do you need to do that 10ms resultion isn't 
>>enough?
>>    
>>
>
>I'm betting that since 10ms is equal to 80 samples, that you would see
>that it is too slow for the current needs. To slow down to a 10ms
>resolution would might require 2 sets of timer routines, one able to
>handle the zapata resolution and then the software timer one.
>  
>
What current needs?  I mean, what are these hardware timers used for:

meetme:  The processing frequency here approximately equals the extra 
delay introduced.  You can easily run meetme conferences 50 times per 
second, instead of 1000 times per second.

iax trunking:  Since the trunk frames only go out every 20ms or whatever 
you've set, clearly you don't need a 1ms timer driving them. 

generators (for playing sounds, etc):  Since these things are being used 
only when you're doing VoIP, you certainly don't need 1ms resolution for 
them.

What am I missing?