Re: [Haskell-cafe] System calls and Haskell threads

On Thu, Nov 3, 2011 at 8:35 AM, Andreas Voellmy wrote:

I just read Kazu Yamamoto's article on a high performance web server in the latest Monad.Reader, and I came across a statement that doesn't sound correct to me. He says:

"When a user thread issues a system call, a context switch occurs. This means that all Haskell user threads stop, and instead the kernel is given the CPU time. "

Is this right?

It is correct in context. Mighttpd does not use the -Nx argument to create multiple OS threads, instead uses a `prefork` model that creates separate processes to balance user invocations. Using multiple processes instead of multiple Haskell threads avoids issues with garbage collection. Regards, Dave