Some Linux Kernel Structures
Interrupt Descriptor Table (IDT)
The Interrupt Descriptor Table (IDT) is a data structure used by the x86 architecture to implement an interrupt vector table. The IDT is used by the processor to determine the correct response to interrupts and exceptions.
Set up during kernel boot-up. For instance, sets interrupt 80 (int $0x80) for calling system calls:
arch/i386/kernel/entry.S System call and low-level fault handling routines.
include/asm-i386/unistd.h System call numbers and macros.
kernel/sys.c System call service routines.
Process Control Block (PCB)
A process control block (PCB) is a data structure used by computer operating systems to store all the information about a process. It is also known as a process descriptor.
In Linux the PCB is named Task structure and is defined in the scheduler code
Learning about Linux Processes
The Art of Linux Kernel Design