[UPDATE] new pid allocation patch (was: Call for testers: New PID allocator patch for -CURRENT)

Hi All,

John Baldwin's proc lock commit today made my patch broken, so I have
revised the patch, and uploaded it to the same position:
http://www.arbornet.org/~junsu/pid.diff

The revised patch has been improved based on the feedback. Basically,

1. Added a new sysctl value kern.pidmax to control the current pid range.
This value can influence the reuse pid period. The initial value is 4096.

2. Change the meaning of PID_MAX back to what it was, and sainty-check
whether the pid is 5 digit based on PID_MAX. (I think it is impossible that
pid expand PID_MAX for the algorithm nature, though.)

3. The initial pid table size is bumped from 1<<5 to 1<<7.

Thanks,

Jun Su