[PATCH 06/16] tracepoint: use new hashtable implementation
From: Sasha Levin <hidden>
Date: 2012-08-14 16:25:38
Also in:
dm-devel, linux-nfs, lkml, netdev
Subsystem:
the rest, tracing · Maintainers:
Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Switch tracepoints to use the new hashtable implementation. This reduces the amount of generic unrelated code in the tracepoints. Signed-off-by: Sasha Levin <redacted> --- kernel/tracepoint.c | 27 +++++++++++---------------- 1 files changed, 11 insertions(+), 16 deletions(-)
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index d96ba22..854df92 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c@@ -26,6 +26,7 @@ #include <linux/slab.h> #include <linux/sched.h> #include <linux/static_key.h> +#include <linux/hashtable.h> extern struct tracepoint * const __start___tracepoints_ptrs[]; extern struct tracepoint * const __stop___tracepoints_ptrs[];
@@ -49,8 +50,7 @@ static LIST_HEAD(tracepoint_module_list); * Protected by tracepoints_mutex. */ #define TRACEPOINT_HASH_BITS 6 -#define TRACEPOINT_TABLE_SIZE (1 << TRACEPOINT_HASH_BITS) -static struct hlist_head tracepoint_table[TRACEPOINT_TABLE_SIZE]; +static DEFINE_HASHTABLE(tracepoint_table, TRACEPOINT_HASH_BITS); /* * Note about RCU :
@@ -191,16 +191,15 @@ tracepoint_entry_remove_probe(struct tracepoint_entry *entry, */ static struct tracepoint_entry *get_tracepoint(const char *name) { - struct hlist_head *head; struct hlist_node *node; struct tracepoint_entry *e; u32 hash = jhash(name, strlen(name), 0); - head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)]; - hlist_for_each_entry(e, node, head, hlist) { + hash_for_each_possible(tracepoint_table, e, node, hlist, hash) { if (!strcmp(name, e->name)) return e; } + return NULL; }
@@ -210,19 +209,13 @@ static struct tracepoint_entry *get_tracepoint(const char *name) */ static struct tracepoint_entry *add_tracepoint(const char *name) { - struct hlist_head *head; - struct hlist_node *node; struct tracepoint_entry *e; size_t name_len = strlen(name) + 1; u32 hash = jhash(name, name_len-1, 0); - head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)]; - hlist_for_each_entry(e, node, head, hlist) { - if (!strcmp(name, e->name)) { - printk(KERN_NOTICE - "tracepoint %s busy\n", name); - return ERR_PTR(-EEXIST); /* Already there */ - } + if (get_tracepoint(name)) { + printk(KERN_NOTICE "tracepoint %s busy\n", name); + return ERR_PTR(-EEXIST); /* Already there */ } /* * Using kmalloc here to allocate a variable length element. Could
@@ -234,7 +227,7 @@ static struct tracepoint_entry *add_tracepoint(const char *name) memcpy(&e->name[0], name, name_len); e->funcs = NULL; e->refcount = 0; - hlist_add_head(&e->hlist, head); + hash_add(tracepoint_table, &e->hlist, hash); return e; }
@@ -244,7 +237,7 @@ static struct tracepoint_entry *add_tracepoint(const char *name) */ static inline void remove_tracepoint(struct tracepoint_entry *e) { - hlist_del(&e->hlist); + hash_del(&e->hlist); kfree(e); }
@@ -722,6 +715,8 @@ struct notifier_block tracepoint_module_nb = { static int init_tracepoints(void) { + hash_init(tracepoint_table); + return register_module_notifier(&tracepoint_module_nb); } __initcall(init_tracepoints);
--
1.7.8.6
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