Timing Subsystem in deep

Course Curriculum

Chapter 1: Programming timing in user space

Lecture 1: date command

Lecture 2: uptime command

Lecture 3: Epoch time

Lecture 4: ctime

Lecture 5: gettimeofday

Lecture 6: Can gettimeofday() be used for measured elapsed time

Lecture 7: Monotonic clock

Lecture 8: CLOCK_BOOTTIME

Lecture 9: CLOCK_MONOTONIC_RAW

Lecture 10: CLOCK_REALTIME

Lecture 11: CLOCK_PROCESS_CPUTIME_ID

Lecture 12: Example to calculate time taken to increment

Lecture 13: Another Example using clock_gettime

Lecture 14: CLOCK_MONOTONIC vs CLOCK_PROCESS_CPUTIME_ID

Lecture 15: CLOCK_THREAD_CPUTIME_ID

Lecture 16: clock_settime

Lecture 17: clock_getres

Lecture 18: times

Lecture 19: getrusage

Chapter 2: Hardware devices used in timing measurement

Lecture 1: Timing Measurements in Linux Kernel

Lecture 2: RTC

Lecture 3: Kernel module example reading RTC

Lecture 4: RTC Interrupts

Lecture 5: RTC IOCTL Interface

Lecture 6: RTC Periodic Interrupts

Lecture 7: RTC Alarm Interrupt

Lecture 8: Why RTC is not used after computer is powered on

Lecture 9: TSC

Lecture 10: Reading TSC from kernel space

Lecture 11: RDTSCP

Lecture 12: Issues using TSC with multiprocessor systems

Lecture 13: Kernel functions for TSC

Lecture 14: Programmable Interval Timer

Lecture 15: Local APIC

Lecture 16: High Precision Event Timer

Lecture 17: Linux Abstraction

Chapter 3: Jiffies

Lecture 1: HZ

Lecture 2: jiffies

Lecture 3: What is the size of jiffies

Lecture 4: Why is jiffies not declared as 64-bit on x86

Lecture 5: Jiffies Wraparound

Lecture 6: What is the initial value of jiffies on boot

Lecture 7: INITIAL_JIFFIES

Lecture 8: Why double casting is needed for INITIAL_JIFFIES macro

Lecture 9: Convert jiffies to seconds milliseconds

Lecture 10: Measuring module loaded time using jiffies

Lecture 11: Can we update jiffies

Lecture 12: Timer Interrupt processing

Lecture 13: Busy looping using jiffies

Lecture 14: Jiffies conversions

Lecture 15: How are busy loops implemented

Lecture 16: What is disadvantage of having periodic interrupts in Linux Kernel

Lecture 17: Configuration of clock interrupts

Chapter 4: Low Resolution TImers

Lecture 1: Introduction to timers

Lecture 2: Implementation of low resolution timers

Lecture 3: Specifying an expiration time

Lecture 4: Which context timer handler runs

Lecture 5: Timer implementation

Lecture 6: Are interrupts disabled while running timer handler

Lecture 7: Whether timer handler runs in softirq or hardirq

Lecture 8: Whether kernel checks all timer entries on each raise softirq

Lecture 9: Deactivate a timer

Lecture 10: del_timer_sync

Lecture 11: timer_pending

Lecture 12: Periodic timers

Lecture 13: Synchronize between process context and timer handler

Lecture 14: Run timer handler every one second

Lecture 15: Timer Flags

Lecture 16: How schedule_timeout works

Lecture 17: Problems with low resolution timers

Chapter 5: ktime_t

Lecture 1: Introduction to high resolution timers

Lecture 2: ktime_t

Lecture 3: Macros and functions for ktime_t

Lecture 4: Macros and functions for add sub ktime_t

Lecture 5: ktime_t conversion functions

Lecture 6: Example of conversion functions

Lecture 7: ktime accessors

Lecture 8: ktime accessors part 2

Lecture 9: ktime accessors part 3

Lecture 10: nanosecond output

Lecture 11: timespec output

Lecture 12: seconds output

Lecture 13: How uptime is implemented

Lecture 14: How gettimeofday is implemented

Lecture 15: How clock_gettime is implemented

Lecture 16: coarse variants

Lecture 17: Why are coarse variants faster

Chapter 6: HRTimers

Lecture 1: Introduction

Lecture 2: Cancel a timer

Lecture 3: Return value of callback timer

Lecture 4: hrtimer_forward_now

Lecture 5: Measuring clock cycles

Lecture 6: Examples of clocks and modes

Lecture 7: hrtimer_callback_running