Timekeeping in the Linux Kernel

Explore the intricacies of timekeeping in the Linux kernel through this comprehensive conference talk. Dive into the core timekeeping code, understanding its crucial role in various kernel functions from low power idle paths to device drivers. Learn how the kernel abstracts hardware, implements NOHZ, timers, hrtimers, cpu-idle, and POSIX clocks. Discover the tick-broadcast mechanism and its importance in maintaining functionality when abstractions break down. Gain insights into topics such as handling clock drift, making operations fast and efficient, implementing ticks in hardware, and managing high-resolution timers. Follow along as the speaker guides you through the complexities of Linux kernel timekeeping, providing a thorough understanding of this essential component.

Intro
there was a counter
POSIX Clocks Comparison
RAT in Action (Read)
RAT in Action (Accumulate - Track)
Juggling Clocks
Handling Clock Drift
Mult to the Rescue!
Making Things Fast and Efficient
Where We Are
What if my system doesn't have a counter?
Let's talk about jiffies
Implementing the tick in hardware
Abstract the Hardware!
Three event_handlers
Ticks During Ide
High Resolution Mode
Tick Devices
Running the Tick
Running the Tich Per-CPU
Stopping the Tick
Tick Broadcast
HRTimers
Summary