Lines Matching +full:trigger +full:- +full:sources

2 Clock sources, Clock events, sched_clock() and delay timers
10 If you grep through the kernel source you will find a number of architecture-
11 specific implementations of clock sources, clockevents and several likewise
12 architecture-specific overrides of the sched_clock() function and some
17 on this timeline, providing facilities such as high-resolution timers.
22 Clock sources
23 -------------
31 n bits which count from 0 to (2^n)-1 and then wraps around to 0 and start over.
36 shall be as stable and correct as possible as compared to a real-world wall
46 When the wall-clock accuracy of the clock source isn't satisfactory, there
48 the user-visible time to RTC clocks in the system or against networked time
70 For real simple clock sources accessed from a single I/O memory location
76 Since a 32-bit counter at say 100 MHz will wrap around to zero after some 43
86 ------------
88 Clock events are the conceptual reverse of clock sources: they take a
92 Clock events are orthogonal to clock sources. The same hardware
95 fire interrupts, so as to trigger events on the system timeline. On an SMP
97 CPU core, so that each core can trigger events independently of any other
109 -------------
111 In addition to the clock sources and clock events there is a special weak
123 Compared to clock sources, sched_clock() has to be very fast: it is called
124 much more often, especially by the scheduler. If you have to do trade-offs
143 The sched_clock() function should be callable in any context, IRQ- and
144 NMI-safe and return a sane value in any context.
146 Some architectures may have a limited set of time sources and lack a nice
147 counter to derive a 64-bit nanosecond value, so for example on the ARM
149 sched_clock() nanosecond base from a 16- or 32-bit counter. Sometimes the
161 --------------------------------------
174 Enter timer-based delays. Using these, a timer read may be used instead of
175 a hard-coded loop for providing the desired delay.