Re: Forprime and posix multithreading

[Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>]

On Mon, Jun 30, 2025 at 10:14:13AM +0000, Piercarlo Giannattasio wrote:
> Good morning,
> I'm trying to code a prime number generator in a specified range, using GP
> and C, and I need to reduce processing times.

What is a prime number generator ? How is it different from forprime ?

> I'm trying to use forprime and posix multithreading, but when executing the
> code I'm exceeding the parisizemax. I've tried with 1-15 threads, assigning
> 16GB of memory only to PARI, but I still get the same error: sometimes it
> only calculates the first iteration of forprime_next...

You need to set threadsizemax too.

> Also, is there any technical documentation for the C implementation, besides
> the one I'm studying (User Guide, Tutorial, Introduction to gp2c,
> Introduction to Parallel GP) ?

Thre are the libpari manual, the examples directory, and of course the PARI source code.

But I suggest you send me your code, I will tell you what you need to read.

Cheers,
Bill.