Linux Kernel Internals

Course details

16 hours real time session + 10 hours monitored hands-on

Ideal For: This training is targeted primarily at software professionals - tech leads, system programmers / developers, maintainers and testers - who would like to delve much deeper into the internal functioning of the Linux operating system.

Post course benefits: Lifetime access to online repository, Mock interview support, project support

Recruitment support: eAgeIT will propose candidates of this program for any open opportunities with its client portfolio. We do not guarantee placement. This will be purely merit based support.

• Good working knowledge of and experience programming using the 'C'
  
• Successfully attended the "LINUX Fundamentals for Software Developers" training program -or-have the equivalent knowledge / skill
  
• Successfully attended the "Advanced LINUX Programming" training program -or-have the equivalent knowledge / skill Implies knowledge / skill sets of: POSIX library and system call API set, process management, IPC mechanisms, etc.
  
• Extensive user-space development experience on a POSIX
  

Course Content

• Linux OS : Fundamental Prerequisites
• OS Architecture
• Processor Protection Levels
• Architecture Layers
• Monolithic / Microkernel / Hybrid OS Architectures
• Tracking Linux kernel changes.
• Practical Guide to Writing Kernel Code with LKMs
• Introduction to Loadable Kernel Modules (LKMs)
• Setting up your Test System
• The Hello World Module
• Compiling, the Makefile, Insertion and Removal
• Lab Assignment.
• Passing Parameters
• Kernel API and ABI.
• Lab Assignment.
• Kernel Architecture and the Process Descriptor
• Timer Interrupt and the Tick Rate (HZ)
• Kernel Architecture in Brief
• Kernel Mapping of Processes and Threads
• Multiple Stacks
• Process Descriptor
• Task List
• Accessing the current task with 'current'
• The task_struct.
• Lab Assignments.
• Linux Memory Management - Essentials
• Introduction
• What is VM; Hardware Paging
• Linux VM Architecture
• (n-Level) Arch-independent Paging on Linux
• 64-bit VM Layout
• Memory (De)Allocation API
• GFP flags and action modifiers
• vmalloc
• Slab Cache API interfaces
• Which API to Use When
• Lab Assignments
• Test the kmalloc limits
• Verify the internal fragmentation (wastage).
• Kernel Segment: Kernel Memory Map on the Linux OS
•  Examining the Kernel Segment - kernel Virtual Address Space.
• Process Virtual Memory Mapping
• The mm_struct
• Memory Regions and VMAs
• Viewing VMAs
• VMAs on 64-bit
• proc: maps, pmap(1), smaps
• smem, smemcap.
• Low-Level API
• Freeing Pages
• kmalloc, kfree
• GFP flags and action modifier
• vmalloc
• Slab Cache API interfaces
• Which API to Use When
• TheLinuxKernelScheduler
• Introduction
• Linux Process State Machine
• Real-Time and Linux
• POSIX Scheduling Policies
• Realtime Policies
• Priority Range
• Pthreads soft-RT example
• taskset
• chrt
• Linux as an RTOS: a mention of the PREEMPT_RT patch.
• Control Groups
• The Need
• Cgroup Model
• Configuration
• Cgroups example for allocating cpu bandwidth.
• Handling Concurrency in the Kernel
• The Need for Atomicity
• Causes of Concurrency in the kernel
• Deadlock Prevention
• Important Guidelines
• Concurrency in the Kernel
• Spinlocks and Mutexes
• The Need
• Understanding when to use which
• The Semaphore Interface
• A note on Spinlock Implementation
• Specialized Locking
• Atomic Operators
• Reader-Writer Locks
• Memory Barriers