My application needs to create thousands of threads, or maybe even more. Can I do this with LinuxThreads?
No. You’re going to run into several hard limits: • Each thread, from the kernel’s standpoint, is one process. Stock Linux kernels (version 2.2 and earlier) are limited to at most 512 processes for the super-user, and half this number for regular users. This can be changed by changing NR_TASKS in include/linux/tasks.h and recompiling the kernel. On the x86 processors at least, architectural constraints seem to limit NR_TASKS to 4090 at most. (It seems that 2.4 kernels have higher limits, though.) • LinuxThreads contains a table of all active threads. This table has room for 1024 threads at most. To increase this limit, you must change PTHREAD_THREADS_MAX in the LinuxThreads/glibc sources and recompile. • By default, each thread reserves 2M of virtual memory space for its stack. This space is just reserved; actual memory is allocated for the stack on demand.
No. You’re going to run into several hard limits: • Each thread, from the kernel’s standpoint, is one process. Stock Linux kernels (version 2.2 and earlier) are limited to at most 512 processes for the super-user, and half this number for regular users. This can be changed by changing NR_TASKS in include/linux/tasks.h and recompiling the kernel. On the x86 processors at least, architectural constraints seem to limit NR_TASKS to 4090 at most. (It seems that 2.4 kernels have higher limits, though.) • LinuxThreads contains a table of all active threads. This table has room for 1024 threads at most. To increase this limit, you must change PTHREAD_THREADS_MAX in the LinuxThreads/glibc sources and recompile. • By default, each thread reserves 2M of virtual memory space for its stack. This space is just reserved; actual memory is allocated for the stack on demand. But still, on a 32-bit processor, the total virtual memory space available for the stacks is on the order of 1G, meaning that more
