[KLUG Programming] Pthreads problem

[Alan Mink]

See below.

Thanks,
Alan
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Peter Buxton wrote:

>On Tue, Dec 30, 2003 at 11:01:09AM -0500, Alan Mink was only escaped
>   alone to tell thee:
>
>  
>
>>I'm having some shared memory/size (??) problems using threads. Is
>>POSIX threads under Linux stable?
>>    
>>
>
>What version of Linux? As I recall, Red Hat 9.0 backported the new
>Native POSIX Thread Library (NPTL) to 2.4. That might have bugs.
>
I'm running RedHat 7.3 (Valhalla) 2.4.18-10smp #1 SMP on a dual CPU 
system w/ 500 MBytes
of main memory

>
>Remember that Linuxthreads != pthreads. There is some mapping to get one
>to match the other. The new NPTL implementation closes this gap.
>
>  
>
>>I originally had very large data arrays over 136 MBytes. I had reduced
>>it to around 70 MBytes.  Just yesterday, for debugging, I reduced it
>>to ~100 KBytes and it seemed to work!?!?  Could there be some memory
>>limitations involved? 
>>    
>>
>
>What is listed in '/proc/sys/kernel/shmmax'? On my 2.6 kernel, it is
>33554432 (32 MB). 
>
Mine has the same! Is this what Threads uses for shared memory limits?
What does it do if you exceed these limits? I didn't see an warnings or
error msgs. Is this just some default constant that I can change? Does 
it have
any impact elsewhere? Are there any real limits for this other than main 
memory size?

>
>  
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