[Asterisk-Users] Child PID's

[Paul Hewlett]

On Thursday 02 March 2006 22:19, Matt Schulte wrote:
> All, I'm not sure how to word this question but we're noticing a lot of
> our asterisk boxes no longer have multiple asterisk child processes.
> i.e. doing a 'ps ax' reveals only 1 asterisk PID when normally I'm used
> to seeing 8+ .. There is no rhyme or reason to it, and we're using the
> safe_asterisk script which has always worked in the past. Ast 1.2.4, zap
> 1.2.4, naturally..
>
> All my research has revealed nothing, regarding this, any suggestions?
> What I'm worried about, of course, is the single process getting
> overloaded with CPU calls and potentially denying service.
>
> 	Matt @ NetLogic

Matt

   On 2.4 kernels you would be using the LinuxThreads implementation of POSIX 
threads. This emulated the POSIX threading model with some limitations - 
signals could only be delivered to the master thread - there was a 'hidden' 
control thread etc... Context switching performance in LinuxThreads was known 
to be poor (sometimes measured in whole seconds) IBM and RedHat worked on 
solving this problem - IBM's effort (NGPT) was abandoned in favour of 
REdHat's (NPTL). NPTL was introduced in RedHat 9 (as I remember). Most modern 
distro's now use NPTL and one can tell this by doing 'ps ax' and seeing only 
one asterisk task instead of many. Asterisk without NPTL is probably not good 
for high thruput sites.

  And Gentoo users beware - only 2006.0 has adopted NPTL as default. 
Previously one had to rebuild the toolchain by specifying USE flags "nptl 
nptlonly" to get NPTL threads (and this takes a long time...)

  Have u upgraded to a more modern distro recently ?

Paul