Table of Contents
Linux Kernel 2.4 Internals.................................................................................................................................1
Tigran Aivazian tigran@veritas.com.......................................................................................................1
1. Booting.................................................................................................................................................1
2. Process and Interrupt Management......................................................................................................1
3. Virtual Filesystem (VFS).....................................................................................................................2
4. Linux Page Cache................................................................................................................................2
5. IPC mechanisms..................................................................................................................................2
1. Booting.................................................................................................................................................2
1.1 Building the Linux Kernel Image......................................................................................................2
1.2 Booting: Overview.............................................................................................................................3
1.3 Booting: BIOS POST.........................................................................................................................4
1.4 Booting: bootsector and setup............................................................................................................4
1.5 Using LILO as a bootloader ..............................................................................................................7
1.6 High level initialisation .....................................................................................................................7
1.7 SMP Bootup on x86...........................................................................................................................9
1.8 Freeing initialisation data and code...................................................................................................9
1.9 Processing kernel command line.....................................................................................................10
2. Process and Interrupt Management....................................................................................................12
2.1 Task Structure and Process Table....................................................................................................12
2.2 Creation and termination of tasks and kernel threads......................................................................15
2.3 Linux Scheduler...............................................................................................................................17
2.4 Linux linked list implementation.....................................................................................................19
2.5 Wait Queues.....................................................................................................................................21
2.6 Kernel Timers..................................................................................................................................24
2.7 Bottom Halves.................................................................................................................................24
2.8 Task Queues.....................................................................................................................................25
2.9 Tasklets............................................................................................................................................26
2.10 Softirqs...........................................................................................................................................26
2.11 How System Calls Are Implemented on i386 Architecture?.........................................................26
2.12 Atomic Operations.........................................................................................................................27
2.13 Spinlocks, Read−write Spinlocks and Big−Reader Spinlocks......................................................28
2.14 Semaphores and read/write Semaphores.......................................................................................30
2.15 Kernel Support for Loading Modules............................................................................................31
3. Virtual Filesystem (VFS)...................................................................................................................34
3.1 Inode Caches and Interaction with Dcache......................................................................................34
3.2 Filesystem Registration/Unregistration...........................................................................................37
3.3 File Descriptor Management............................................................................................................39
3.4 File Structure Management..............................................................................................................40
3.5 Superblock and Mountpoint Management.......................................................................................43
3.6 Example Virtual Filesystem: pipefs.................................................................................................46
3.7 Example Disk Filesystem: BFS.......................................................................................................48
3.8 Execution Domains and Binary Formats.........................................................................................50
4. Linux Page Cache..............................................................................................................................51
5. IPC mechanisms................................................................................................................................54
5.1 Semaphores.....................................................................................................................................54
Semaphore System Call Interfaces..........................................................................................54
sys_semget()............................................................................................................................54
sys_semctl().............................................................................................................................54
Linux Kernel 2.4 Internals
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