> > Basically, it's a big bitmask, where each bit represents a possible process > > id (can be 2 gigs if we allow all positive ints!). > > I think you mean 2 giga-bit, for 256MB worth of memory, right ? > > And AFAIU the PID_MAX_LIMIT is at a maximum of 4 million PIDs in > include/linux/threads.h, which means 512MB worth of memory for a > bitmask.
PID space is limited to 30 bits per FUTEX_TID_MASK, still, stupid large :-)
