So the book is split into four major sections: Measurement, Observation, KUtrace, Reasoning.
"Measurement" delves into understanding and measuring four fundamental resources: CPU, Memory, Disk/SSD, and Network. This section is quite dense and explores both the depth and breadth of understanding performance of programs. For example, there is a chapter on optimizing code to use caches more efficiently. Though I will say this section is obviously not a complete exploration of all aspects of performance as there are many many many more things which can affect the performance in such complex systems like modern computers. But what Dick does is in this section is to give you more tools in your toolbelt to understand performance better.
"Observation" looks at existing tooling (so profilers, tracing tools, etc.) and discusses where they are useful or where they fall short.
"KUtrace" introduces KUtrace, its kernel module, and its timeline visualization tool. It discusses its design and implementation and why is it so fast and low-overhead.
"Reasoning" has case studies that looks at particular kinds of performance pathologies such as "waiting for CPUs" etc. Dick uses KUtrace here to tease out the underlying inefficiencies in the analyzed programs.
So the first two sections are essentially orthogonal to if you want to use KUtrace or not, but the last two sections are about KUtrace and how to use it to understand performance bottlenecks. Even if you don't use KUtrace, the "Reasoning" section can still be insightful imo as KUtrace is just a tool at the end of the day, and the real insight is why or what is causing the performance issue.
"Measurement" delves into understanding and measuring four fundamental resources: CPU, Memory, Disk/SSD, and Network. This section is quite dense and explores both the depth and breadth of understanding performance of programs. For example, there is a chapter on optimizing code to use caches more efficiently. Though I will say this section is obviously not a complete exploration of all aspects of performance as there are many many many more things which can affect the performance in such complex systems like modern computers. But what Dick does is in this section is to give you more tools in your toolbelt to understand performance better.
"Observation" looks at existing tooling (so profilers, tracing tools, etc.) and discusses where they are useful or where they fall short.
"KUtrace" introduces KUtrace, its kernel module, and its timeline visualization tool. It discusses its design and implementation and why is it so fast and low-overhead.
"Reasoning" has case studies that looks at particular kinds of performance pathologies such as "waiting for CPUs" etc. Dick uses KUtrace here to tease out the underlying inefficiencies in the analyzed programs.
So the first two sections are essentially orthogonal to if you want to use KUtrace or not, but the last two sections are about KUtrace and how to use it to understand performance bottlenecks. Even if you don't use KUtrace, the "Reasoning" section can still be insightful imo as KUtrace is just a tool at the end of the day, and the real insight is why or what is causing the performance issue.