Re: program starts with 3 threads
On Fri, 2004-07-02 at 16:09, jono wrote:
> testing/unstable 2.4.25 i686
>
> When I run a daemon (written for a telephony card) or the expect
> application which uses the daemon, they both start with 3 processes.
> I've noticed the same behavior with S20xprint and nautilus.
>
> The same daemon and application on redhat9 (2.4.20-8 i686) starts with
> only the one process. Its causing errors in our application so I was
> wondering if there was any reason for this and if it is debian specific?
>
> TIA, please cc direct. Regards, Jono.
>
Hi Jono,
My memory on this is a little rusty now. However I believe the story
goes as follows:
With normal versions of the Linux 2.4.x kernel, the "ps" command shows
each *thread* as a separate process.
The new Linux 2.6.x kernel has a completely rewritten threading
implementation and "ps" shows only 1 entry for a multi-threaded process.
RedHat has a tradition of distributing fairly heavily patched kernels; I
believe that they included the new threading model into the 2.4.x kernel
that was included with RH9.
I suspect the app you are concerned about is starting *1* process with
*3* threads. If that is the case, then what you are seeing on Debian is
normal for distributions running 2.4.x kernels. RH9, despite running a
2.4-based kernel behaves more like 2.6.x due to special patches in its
kernel version.
I remember this because RH9's early adoption of the new threading
implementation broke many many applications (eg IBM MQSeries), and I
cursed them for it vigorously.
Regards,
Simon
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