From bf6a9b8336ba12672755c2ae898b0abe42c7a5ac Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Tue, 21 Dec 2010 17:55:14 +0800 Subject: 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 LKML-Reference: <4D107982.9090700@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- lib/plist.c | 54 +++++++++++++++++++++++++++++++++++------------------- 1 file changed, 35 insertions(+), 19 deletions(-) (limited to 'lib') diff --git a/lib/plist.c b/lib/plist.c index 1471988..8c614d0 100644 --- a/lib/plist.c +++ b/lib/plist.c @@ -59,7 +59,8 @@ static void plist_check_head(struct plist_head *head) WARN_ON_SMP(!raw_spin_is_locked(head->rawlock)); if (head->spinlock) WARN_ON_SMP(!spin_is_locked(head->spinlock)); - plist_check_list(&head->prio_list); + if (!plist_head_empty(head)) + plist_check_list(&plist_first(head)->prio_list); plist_check_list(&head->node_list); } @@ -75,25 +76,33 @@ static void plist_check_head(struct plist_head *head) */ void plist_add(struct plist_node *node, struct plist_head *head) { - struct plist_node *iter; + struct plist_node *first, *iter, *prev = NULL; + struct list_head *node_next = &head->node_list; plist_check_head(head); WARN_ON(!plist_node_empty(node)); + WARN_ON(!list_empty(&node->prio_list)); - list_for_each_entry(iter, &head->prio_list, plist.prio_list) { - if (node->prio < iter->prio) - goto lt_prio; - else if (node->prio == iter->prio) { - iter = list_entry(iter->plist.prio_list.next, - struct plist_node, plist.prio_list); - goto eq_prio; + if (plist_head_empty(head)) + goto ins_node; + + first = iter = plist_first(head); + + do { + if (node->prio < iter->prio) { + node_next = &iter->node_list; + break; } - } -lt_prio: - list_add_tail(&node->plist.prio_list, &iter->plist.prio_list); -eq_prio: - list_add_tail(&node->plist.node_list, &iter->plist.node_list); + prev = iter; + iter = list_entry(iter->prio_list.next, + struct plist_node, prio_list); + } while (iter != first); + + if (!prev || prev->prio != node->prio) + list_add_tail(&node->prio_list, &iter->prio_list); +ins_node: + list_add_tail(&node->node_list, node_next); plist_check_head(head); } @@ -108,14 +117,21 @@ void plist_del(struct plist_node *node, struct plist_head *head) { plist_check_head(head); - if (!list_empty(&node->plist.prio_list)) { - struct plist_node *next = plist_first(&node->plist); + if (!list_empty(&node->prio_list)) { + if (node->node_list.next != &head->node_list) { + struct plist_node *next; + + next = list_entry(node->node_list.next, + struct plist_node, node_list); - list_move_tail(&next->plist.prio_list, &node->plist.prio_list); - list_del_init(&node->plist.prio_list); + /* add the next plist_node into prio_list */ + if (list_empty(&next->prio_list)) + list_add(&next->prio_list, &node->prio_list); + } + list_del_init(&node->prio_list); } - list_del_init(&node->plist.node_list); + list_del_init(&node->node_list); plist_check_head(head); } -- cgit v1.1 From 6d55da53db3d9b911f69f2ce1e5fb8943eafe057 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Tue, 21 Dec 2010 17:55:18 +0800 Subject: plist: Add priority list test Add test code for checking plist when the kernel is booting. Signed-off-by: Lai Jiangshan LKML-Reference: <4D107986.1010302@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- lib/plist.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 80 insertions(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/plist.c b/lib/plist.c index 8c614d0..0ae7e64 100644 --- a/lib/plist.c +++ b/lib/plist.c @@ -28,6 +28,8 @@ #ifdef CONFIG_DEBUG_PI_LIST +static struct plist_head test_head; + static void plist_check_prev_next(struct list_head *t, struct list_head *p, struct list_head *n) { @@ -54,7 +56,7 @@ static void plist_check_list(struct list_head *top) static void plist_check_head(struct plist_head *head) { - WARN_ON(!head->rawlock && !head->spinlock); + WARN_ON(head != &test_head && !head->rawlock && !head->spinlock); if (head->rawlock) WARN_ON_SMP(!raw_spin_is_locked(head->rawlock)); if (head->spinlock) @@ -135,3 +137,80 @@ void plist_del(struct plist_node *node, struct plist_head *head) plist_check_head(head); } + +#ifdef CONFIG_DEBUG_PI_LIST +#include +#include +#include + +static struct plist_node __initdata test_node[241]; + +static void __init plist_test_check(int nr_expect) +{ + struct plist_node *first, *prio_pos, *node_pos; + + if (plist_head_empty(&test_head)) { + BUG_ON(nr_expect != 0); + return; + } + + prio_pos = first = plist_first(&test_head); + plist_for_each(node_pos, &test_head) { + if (nr_expect-- < 0) + break; + if (node_pos == first) + continue; + if (node_pos->prio == prio_pos->prio) { + BUG_ON(!list_empty(&node_pos->prio_list)); + continue; + } + + BUG_ON(prio_pos->prio > node_pos->prio); + BUG_ON(prio_pos->prio_list.next != &node_pos->prio_list); + prio_pos = node_pos; + } + + BUG_ON(nr_expect != 0); + BUG_ON(prio_pos->prio_list.next != &first->prio_list); +} + +static int __init plist_test(void) +{ + int nr_expect = 0, i, loop; + unsigned int r = local_clock(); + + printk(KERN_INFO "start plist test\n"); + plist_head_init(&test_head, NULL); + for (i = 0; i < ARRAY_SIZE(test_node); i++) + plist_node_init(test_node + i, 0); + + for (loop = 0; loop < 1000; loop++) { + r = r * 193939 % 47629; + i = r % ARRAY_SIZE(test_node); + if (plist_node_empty(test_node + i)) { + r = r * 193939 % 47629; + test_node[i].prio = r % 99; + plist_add(test_node + i, &test_head); + nr_expect++; + } else { + plist_del(test_node + i, &test_head); + nr_expect--; + } + plist_test_check(nr_expect); + } + + for (i = 0; i < ARRAY_SIZE(test_node); i++) { + if (plist_node_empty(test_node + i)) + continue; + plist_del(test_node + i, &test_head); + nr_expect--; + plist_test_check(nr_expect); + } + + printk(KERN_INFO "end plist test\n"); + return 0; +} + +module_init(plist_test); + +#endif -- cgit v1.1