8 #include <linux/posix-timers.h>
20 #include "posix-timers.h"
289  * CPU timers armed. Before starting a timer it's required to check whether
534  * Clean out CPU timers which are still armed when a thread exits. The
535  * timers are only removed from the list. No other updates are done. The
536  * corresponding posix timers are still accessible, but cannot be rearmed.
562  * Insert the timer on the appropriate list before any timers that
578 	 * for process timers we share expiration cache with itimers  in arm_timer()
579 	 * and RLIMIT_CPU and for thread timers with RLIMIT_RTTIME.  in arm_timer()
608 		/* Disable oneshot timers */  in cpu_timer_fire()
617  * Guts of sys_timer_settime for CPU timers.
714 	 * SIGEV_NONE timers are never armed. In case the timer is not  in posix_cpu_timer_set()
747 	 * Make sure that interval timers are moved forward for the  in __posix_cpu_timer_get()
749 	 *  - SIGEV_NONE timers which are never armed  in __posix_cpu_timer_get()
750 	 *  - Timers which expired, but the signal has not yet been  in __posix_cpu_timer_get()
759 	 * Expired interval timers cannot have a remaining time <= 0.  in __posix_cpu_timer_get()
768 		 * expired! Timers which have a real signal delivery mode  in __posix_cpu_timer_get()
812 		/* Limit the number of timers to expire at once */  in collect_timerqueue()
861  * Check for any per-thread CPU timers that have fired and move them off
863  * tsk->it_*_expires values to reflect the remaining thread CPU timers.
882 	 * Check for the special case thread timers.  in check_thread_timers()
938  * Check for any per-thread CPU timers that have fired and move them
939  * off the tsk->*_timers list onto the firing list.  Per-thread timers
951 	 * If there are no active process wide timers (POSIX 1.b, itimers,  in check_process_timers()
959 	 * Signify that a thread is checking for process timers.  in check_process_timers()
972 	 * Check for the special case process timers.  in check_process_timers()
1053  * task_cputimers_expired - Check whether posix CPU timers are expired
1074  * fastpath_timer_check - POSIX CPU timers fast path.
1078  * Check the task and thread group timers.  If both are zero (there are no
1079  * timers set) return false.  Otherwise snapshot the task and thread group
1080  * timers and compare them with the corresponding expiration times.  Return
1099 	 * Check if thread group timers expired when timers are active and  in fastpath_timer_check()
1180  * Clear existing posix CPU timers task work.
1197  * Initialize posix CPU timers task work in init task. Out of line to
1221 	/* Schedule task work to actually expire the timers */  in __run_posix_cpu_timers()
1233 	 * timers, so no tick can happen and the fast path check can be  in posix_cpu_timers_enable_work()
1242 	 * On RT enabled kernels ticks can happen while the expired timers  in posix_cpu_timers_enable_work()
1248 	 * advanced since the collecting of expired timers started. If  in posix_cpu_timers_enable_work()
1250 	 * newly expired timers, reenable the fast path check in the timer  in posix_cpu_timers_enable_work()
1251 	 * interrupt. If there are newly expired timers, return false and  in posix_cpu_timers_enable_work()
1315 		 * tsk->cpu_timers[N] all the timers that are firing, and  in handle_posix_cpu_timers()
1324 		 * because nothing can have queued or modified timers after  in handle_posix_cpu_timers()
1330 		 * the loop is not relevant as timers will be directly  in handle_posix_cpu_timers()
1365 	 * Now that all the timers on our list have the firing flag,  in handle_posix_cpu_timers()
1399  * already updated our counts.  We need to check if any timers fire now.
1417 	 * group timers.  If that's so, just return.  in run_posix_cpu_timers()
1426  * Set one of the process-wide special case CPU timers or RLIMIT_CPU.