cregit-Linux how code gets into the kernel

Release 4.12 include/linux/plist.h

Directory: include/linux
/*
 * Descending-priority-sorted double-linked list
 *
 * (C) 2002-2003 Intel Corp
 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>.
 *
 * 2001-2005 (c) MontaVista Software, Inc.
 * Daniel Walker <dwalker@mvista.com>
 *
 * (C) 2005 Thomas Gleixner <tglx@linutronix.de>
 *
 * Simplifications of the original code by
 * Oleg Nesterov <oleg@tv-sign.ru>
 *
 * Licensed under the FSF's GNU Public License v2 or later.
 *
 * Based on simple lists (include/linux/list.h).
 *
 * This is a priority-sorted list of nodes; each node has a
 * priority from INT_MIN (highest) to INT_MAX (lowest).
 *
 * Addition is O(K), removal is O(1), change of priority of a node is
 * O(K) and K is the number of RT priority levels used in the system.
 * (1 <= K <= 99)
 *
 * This list is really a list of lists:
 *
 *  - The tier 1 list is the prio_list, different priority nodes.
 *
 *  - The tier 2 list is the node_list, serialized nodes.
 *
 * Simple ASCII art explanation:
 *
 * pl:prio_list (only for plist_node)
 * nl:node_list
 *   HEAD|             NODE(S)
 *       |
 *       ||------------------------------------|
 *       ||->|pl|<->|pl|<--------------->|pl|<-|
 *       |   |10|   |21|   |21|   |21|   |40|   (prio)
 *       |   |  |   |  |   |  |   |  |   |  |
 *       |   |  |   |  |   |  |   |  |   |  |
 * |->|nl|<->|nl|<->|nl|<->|nl|<->|nl|<->|nl|<-|
 * |-------------------------------------------|
 *
 * The nodes on the prio_list list are sorted by priority to simplify
 * the insertion of new nodes. There are no nodes with duplicate
 * priorites on the list.
 *
 * The nodes on the node_list are ordered by priority and can contain
 * entries which have the same priority. Those entries are ordered
 * FIFO
 *
 * Addition means: look for the prio_list node in the prio_list
 * for the priority of the node and insert it before the node_list
 * entry of the next prio_list node. If it is the first node of
 * that priority, add it to the prio_list in the right position and
 * insert it into the serialized node_list list
 *
 * Removal means remove it from the node_list and remove it from
 * the prio_list if the node_list list_head is non empty. In case
 * of removal from the prio_list it must be checked whether other
 * entries of the same priority are on the list or not. If there
 * is another entry of the same priority then this entry has to
 * replace the removed entry on the prio_list. If the entry which
 * is removed is the only entry of this priority then a simple
 * remove from both list is sufficient.
 *
 * INT_MIN is the highest priority, 0 is the medium highest, INT_MAX
 * is lowest priority.
 *
 * No locking is done, up to the caller.
 *
 */
#ifndef _LINUX_PLIST_H_

#define _LINUX_PLIST_H_

#include <linux/kernel.h>
#include <linux/list.h>


struct plist_head {
	
struct list_head node_list;
};


struct plist_node {
	
int			prio;
	
struct list_head	prio_list;
	
struct list_head	node_list;
};

/**
 * PLIST_HEAD_INIT - static struct plist_head initializer
 * @head:       struct plist_head variable name
 */

#define PLIST_HEAD_INIT(head)				\
{                                                       \
        .node_list = LIST_HEAD_INIT((head).node_list)   \
}

/**
 * PLIST_HEAD - declare and init plist_head
 * @head:       name for struct plist_head variable
 */

#define PLIST_HEAD(head) \
	struct plist_head head = PLIST_HEAD_INIT(head)

/**
 * PLIST_NODE_INIT - static struct plist_node initializer
 * @node:       struct plist_node variable name
 * @__prio:     initial node priority
 */

#define PLIST_NODE_INIT(node, __prio)			\
{                                                       \
        .prio  = (__prio),                              \
        .prio_list = LIST_HEAD_INIT((node).prio_list),  \
        .node_list = LIST_HEAD_INIT((node).node_list),  \
}

/**
 * plist_head_init - dynamic struct plist_head initializer
 * @head:       &struct plist_head pointer
 */

static inline void plist_head_init(struct plist_head *head) { INIT_LIST_HEAD(&head->node_list); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner1050.00%150.00%
Ingo Molnar1050.00%150.00%
Total20100.00%2100.00%

/** * plist_node_init - Dynamic struct plist_node initializer * @node: &struct plist_node pointer * @prio: initial node priority */
static inline void plist_node_init(struct plist_node *node, int prio) { node->prio = prio; INIT_LIST_HEAD(&node->prio_list); INIT_LIST_HEAD(&node->node_list); }

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Ingo Molnar2772.97%150.00%
Lai Jiangshan1027.03%150.00%
Total37100.00%2100.00%

extern void plist_add(struct plist_node *node, struct plist_head *head); extern void plist_del(struct plist_node *node, struct plist_head *head); extern void plist_requeue(struct plist_node *node, struct plist_head *head); /** * plist_for_each - iterate over the plist * @pos: the type * to use as a loop counter * @head: the head for your list */ #define plist_for_each(pos, head) \ list_for_each_entry(pos, &(head)->node_list, node_list) /** * plist_for_each_continue - continue iteration over the plist * @pos: the type * to use as a loop cursor * @head: the head for your list * * Continue to iterate over plist, continuing after the current position. */ #define plist_for_each_continue(pos, head) \ list_for_each_entry_continue(pos, &(head)->node_list, node_list) /** * plist_for_each_safe - iterate safely over a plist of given type * @pos: the type * to use as a loop counter * @n: another type * to use as temporary storage * @head: the head for your list * * Iterate over a plist of given type, safe against removal of list entry. */ #define plist_for_each_safe(pos, n, head) \ list_for_each_entry_safe(pos, n, &(head)->node_list, node_list) /** * plist_for_each_entry - iterate over list of given type * @pos: the type * to use as a loop counter * @head: the head for your list * @mem: the name of the list_head within the struct */ #define plist_for_each_entry(pos, head, mem) \ list_for_each_entry(pos, &(head)->node_list, mem.node_list) /** * plist_for_each_entry_continue - continue iteration over list of given type * @pos: the type * to use as a loop cursor * @head: the head for your list * @m: the name of the list_head within the struct * * Continue to iterate over list of given type, continuing after * the current position. */ #define plist_for_each_entry_continue(pos, head, m) \ list_for_each_entry_continue(pos, &(head)->node_list, m.node_list) /** * plist_for_each_entry_safe - iterate safely over list of given type * @pos: the type * to use as a loop counter * @n: another type * to use as temporary storage * @head: the head for your list * @m: the name of the list_head within the struct * * Iterate over list of given type, safe against removal of list entry. */ #define plist_for_each_entry_safe(pos, n, head, m) \ list_for_each_entry_safe(pos, n, &(head)->node_list, m.node_list) /** * plist_head_empty - return !0 if a plist_head is empty * @head: &struct plist_head pointer */
static inline int plist_head_empty(const struct plist_head *head) { return list_empty(&head->node_list); }

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PersonTokensPropCommitsCommitProp
Ingo Molnar22100.00%1100.00%
Total22100.00%1100.00%

/** * plist_node_empty - return !0 if plist_node is not on a list * @node: &struct plist_node pointer */
static inline int plist_node_empty(const struct plist_node *node) { return list_empty(&node->node_list); }

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PersonTokensPropCommitsCommitProp
Ingo Molnar2090.91%150.00%
Lai Jiangshan29.09%150.00%
Total22100.00%2100.00%

/* All functions below assume the plist_head is not empty. */ /** * plist_first_entry - get the struct for the first entry * @head: the &struct plist_head pointer * @type: the type of the struct this is embedded in * @member: the name of the list_head within the struct */ #ifdef CONFIG_DEBUG_PI_LIST # define plist_first_entry(head, type, member) \ ({ \ WARN_ON(plist_head_empty(head)); \ container_of(plist_first(head), type, member); \ }) #else # define plist_first_entry(head, type, member) \ container_of(plist_first(head), type, member) #endif /** * plist_last_entry - get the struct for the last entry * @head: the &struct plist_head pointer * @type: the type of the struct this is embedded in * @member: the name of the list_head within the struct */ #ifdef CONFIG_DEBUG_PI_LIST # define plist_last_entry(head, type, member) \ ({ \ WARN_ON(plist_head_empty(head)); \ container_of(plist_last(head), type, member); \ }) #else # define plist_last_entry(head, type, member) \ container_of(plist_last(head), type, member) #endif /** * plist_next - get the next entry in list * @pos: the type * to cursor */ #define plist_next(pos) \ list_next_entry(pos, node_list) /** * plist_prev - get the prev entry in list * @pos: the type * to cursor */ #define plist_prev(pos) \ list_prev_entry(pos, node_list) /** * plist_first - return the first node (and thus, highest priority) * @head: the &struct plist_head pointer * * Assumes the plist is _not_ empty. */
static inline struct plist_node *plist_first(const struct plist_head *head) { return list_entry(head->node_list.next, struct plist_node, node_list); }

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Ingo Molnar30100.00%1100.00%
Total30100.00%1100.00%

/** * plist_last - return the last node (and thus, lowest priority) * @head: the &struct plist_head pointer * * Assumes the plist is _not_ empty. */
static inline struct plist_node *plist_last(const struct plist_head *head) { return list_entry(head->node_list.prev, struct plist_node, node_list); }

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James Bottomley30100.00%1100.00%
Total30100.00%1100.00%

#endif

Overall Contributors

PersonTokensPropCommitsCommitProp
Ingo Molnar25958.86%110.00%
Dan Streetman6514.77%220.00%
James Bottomley6214.09%110.00%
Lai Jiangshan245.45%110.00%
Thomas Gleixner153.41%220.00%
Randy Dunlap71.59%110.00%
Andrey Utkin51.14%110.00%
Dima Zavin30.68%110.00%
Total440100.00%10100.00%
Directory: include/linux
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