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authorLai Jiangshan <laijs@cn.fujitsu.com>2010-12-21 17:55:14 +0800
committerSteven Rostedt <rostedt@goodmis.org>2011-03-11 15:13:26 -0500
commitbf6a9b8336ba12672755c2ae898b0abe42c7a5ac (patch)
treec85f2b2acac9bf9b88e0c19d90d252b1780e0d35 /include/linux/plist.h
parent017f2b239dabb2740b91df162e004371b861f371 (diff)
downloadlwn-bf6a9b8336ba12672755c2ae898b0abe42c7a5ac.tar.gz
lwn-bf6a9b8336ba12672755c2ae898b0abe42c7a5ac.zip
plist: Shrink struct plist_head
struct plist_head is used in struct task_struct as well as struct rtmutex. If we can make it smaller, it will also make these structures smaller as well. The field prio_list in struct plist_head is seldom used and we can get its information from the plist_nodes. Removing this field will decrease the size of plist_head by half. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107982.9090700@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'include/linux/plist.h')
-rw-r--r--include/linux/plist.h47
1 files changed, 24 insertions, 23 deletions
diff --git a/include/linux/plist.h b/include/linux/plist.h
index 7254eda078e5..c9b9f322c8d8 100644
--- a/include/linux/plist.h
+++ b/include/linux/plist.h
@@ -31,15 +31,17 @@
*
* Simple ASCII art explanation:
*
- * |HEAD |
- * | |
- * |prio_list.prev|<------------------------------------|
- * |prio_list.next|<->|pl|<->|pl|<--------------->|pl|<-|
- * |10 | |10| |21| |21| |21| |40| (prio)
- * | | | | | | | | | | | |
- * | | | | | | | | | | | |
- * |node_list.next|<->|nl|<->|nl|<->|nl|<->|nl|<->|nl|<-|
- * |node_list.prev|<------------------------------------|
+ * 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
@@ -78,7 +80,6 @@
#include <linux/spinlock_types.h>
struct plist_head {
- struct list_head prio_list;
struct list_head node_list;
#ifdef CONFIG_DEBUG_PI_LIST
raw_spinlock_t *rawlock;
@@ -88,7 +89,8 @@ struct plist_head {
struct plist_node {
int prio;
- struct plist_head plist;
+ struct list_head prio_list;
+ struct list_head node_list;
};
#ifdef CONFIG_DEBUG_PI_LIST
@@ -100,7 +102,6 @@ struct plist_node {
#endif
#define _PLIST_HEAD_INIT(head) \
- .prio_list = LIST_HEAD_INIT((head).prio_list), \
.node_list = LIST_HEAD_INIT((head).node_list)
/**
@@ -133,7 +134,8 @@ struct plist_node {
#define PLIST_NODE_INIT(node, __prio) \
{ \
.prio = (__prio), \
- .plist = { _PLIST_HEAD_INIT((node).plist) }, \
+ .prio_list = LIST_HEAD_INIT((node).prio_list), \
+ .node_list = LIST_HEAD_INIT((node).node_list), \
}
/**
@@ -144,7 +146,6 @@ struct plist_node {
static inline void
plist_head_init(struct plist_head *head, spinlock_t *lock)
{
- INIT_LIST_HEAD(&head->prio_list);
INIT_LIST_HEAD(&head->node_list);
#ifdef CONFIG_DEBUG_PI_LIST
head->spinlock = lock;
@@ -160,7 +161,6 @@ plist_head_init(struct plist_head *head, spinlock_t *lock)
static inline void
plist_head_init_raw(struct plist_head *head, raw_spinlock_t *lock)
{
- INIT_LIST_HEAD(&head->prio_list);
INIT_LIST_HEAD(&head->node_list);
#ifdef CONFIG_DEBUG_PI_LIST
head->rawlock = lock;
@@ -176,7 +176,8 @@ plist_head_init_raw(struct plist_head *head, raw_spinlock_t *lock)
static inline void plist_node_init(struct plist_node *node, int prio)
{
node->prio = prio;
- plist_head_init(&node->plist, NULL);
+ INIT_LIST_HEAD(&node->prio_list);
+ INIT_LIST_HEAD(&node->node_list);
}
extern void plist_add(struct plist_node *node, struct plist_head *head);
@@ -188,7 +189,7 @@ extern void plist_del(struct plist_node *node, struct plist_head *head);
* @head: the head for your list
*/
#define plist_for_each(pos, head) \
- list_for_each_entry(pos, &(head)->node_list, plist.node_list)
+ list_for_each_entry(pos, &(head)->node_list, node_list)
/**
* plist_for_each_safe - iterate safely over a plist of given type
@@ -199,7 +200,7 @@ extern void plist_del(struct plist_node *node, struct plist_head *head);
* 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, plist.node_list)
+ list_for_each_entry_safe(pos, n, &(head)->node_list, node_list)
/**
* plist_for_each_entry - iterate over list of given type
@@ -208,7 +209,7 @@ extern void plist_del(struct plist_node *node, struct plist_head *head);
* @mem: the name of the list_struct within the struct
*/
#define plist_for_each_entry(pos, head, mem) \
- list_for_each_entry(pos, &(head)->node_list, mem.plist.node_list)
+ list_for_each_entry(pos, &(head)->node_list, mem.node_list)
/**
* plist_for_each_entry_safe - iterate safely over list of given type
@@ -220,7 +221,7 @@ extern void plist_del(struct plist_node *node, struct plist_head *head);
* 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.plist.node_list)
+ list_for_each_entry_safe(pos, n, &(head)->node_list, m.node_list)
/**
* plist_head_empty - return !0 if a plist_head is empty
@@ -237,7 +238,7 @@ static inline int plist_head_empty(const struct plist_head *head)
*/
static inline int plist_node_empty(const struct plist_node *node)
{
- return plist_head_empty(&node->plist);
+ return list_empty(&node->node_list);
}
/* All functions below assume the plist_head is not empty. */
@@ -285,7 +286,7 @@ static inline int plist_node_empty(const struct plist_node *node)
static inline struct plist_node *plist_first(const struct plist_head *head)
{
return list_entry(head->node_list.next,
- struct plist_node, plist.node_list);
+ struct plist_node, node_list);
}
/**
@@ -297,7 +298,7 @@ static inline struct plist_node *plist_first(const struct plist_head *head)
static inline struct plist_node *plist_last(const struct plist_head *head)
{
return list_entry(head->node_list.prev,
- struct plist_node, plist.node_list);
+ struct plist_node, node_list);
}
#endif