RHEL 6.2 pthread_create EAGAIN

I am using RHEL 6.2 on x64, on a physical box with 32GB RAM and a 2-socket ( 24 logical cores), no virtualisation.

I'm getting EAGAIN from pthread_create from a batch job, when there's no other users (except myself) connected to the box. There's almost no swap used.

I can restrict the number of threads the batch job starts, but it starts only 23 threads I believe.

I'm not a sysadmin - are there any tuneable RHEL 6.2 parameters that I can adjust to reduce the incidence of pthread_create EAGAIN errors?