process.h File Reference

Process data structures and functions. More...

Go to the source code of this file.

Classes
struct	sched_entity_t
	This structure is used to track the statistics of a process. More...
struct	thread_struct_t
	Stores the status of CPU and FPU registers. More...
struct	task_struct
	this is our task object. Every process in the system has this, and it holds a lot of information. It’ll hold mm information, it’s name, statistics, etc.. More...

Macros
#define	TASK_NAME_MAX_LENGTH   100
	The maximum length of a name for a task_struct.
#define	DEFAULT_STACK_SIZE   (1 * M)
	The default dimension of the stack of a process (1 MByte).

Typedefs
typedef struct sched_entity_t	sched_entity_t
	This structure is used to track the statistics of a process. More...
typedef struct thread_struct_t	thread_struct_t
	Stores the status of CPU and FPU registers.
typedef struct task_struct	task_struct
	this is our task object. Every process in the system has this, and it holds a lot of information. It’ll hold mm information, it’s name, statistics, etc..

Functions
int	init_tasking (void)
	Initialize the task management. More...
task_struct *	process_create_init (const char *path)
	Create and spawn the init process. More...

Detailed Description

Process data structures and functions.

Copyright

(c) 2014-2024 This file is distributed under the MIT License. See LICENSE.md for details.

Typedef Documentation

sched_entity_t

typedef struct sched_entity_t sched_entity_t

This structure is used to track the statistics of a process.

While the other variables also play a role in CFS decisions'algorithm, vruntime is by far the core variable which needs more attention as to understand the scheduling decision process.

The nice value is a user-space and priority 'prio' is the process's actual priority that use by Linux kernel. In linux system priorities are 0 to 139 in which 0 to 99 for real time and 100 to 139 for users. The nice value range is -20 to +19 where -20 is highest, 0 default and +19 is lowest. relation between nice value and priority is : PR = 20 + NI.

Function Documentation

init_tasking()

int init_tasking

(

void

)

Initialize the task management.

Returns

1 success, 0 failure.

process_create_init()

task_struct* process_create_init

(

const char *

path

)

Create and spawn the init process.

Parameters

path	Path of the init program.

Returns

Pointer to init process.