8d809d5061
- Move callout thread creation from kern_intr.c to kern_timeout.c - Call callout_tick() on every processor via hardclock_cpu() rather than inspecting callout internal details in kern_clock.c. - Remove callout implementation details from callout.h - Package up all of the global variables into a per-cpu callout structure. - Start one thread per-cpu. Threads are not strictly bound. They prefer to execute on the native cpu but may migrate temporarily if interrupts are starving callout processing. - Run all callouts by default in the thread for cpu0 to maintain current ordering and concurrency guarantees. Many consumers may not properly handle concurrent execution. - The new callout_reset_on() api allows specifying a particular cpu to execute the callout on. This may migrate a callout to a new cpu. callout_reset() schedules on the last assigned cpu while callout_reset_curcpu() schedules on the current cpu. Reviewed by: phk Sponsored by: Nokia