[PATCH 16/16] tracing output: use new hashtable implementation
From: Sasha Levin <hidden>
Date: 2012-08-14 16:26:43
Also in:
dm-devel, linux-nfs, lkml, netdev
Subsystem:
the rest, tracing · Maintainers:
Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Switch tracing to use the new hashtable implementation. This reduces the amount of generic unrelated code in the tracing module. Signed-off-by: Sasha Levin <redacted> --- kernel/trace/trace_output.c | 20 ++++++++------------ 1 files changed, 8 insertions(+), 12 deletions(-)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 123b189..1324c1a 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c@@ -8,15 +8,15 @@ #include <linux/module.h> #include <linux/mutex.h> #include <linux/ftrace.h> +#include <linux/hashtable.h> #include "trace_output.h" -/* must be a power of 2 */ -#define EVENT_HASHSIZE 128 +#define EVENT_HASH_BITS 7 DECLARE_RWSEM(trace_event_mutex); -static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly; +static DEFINE_HASHTABLE(event_hash, EVENT_HASH_BITS); static int next_event_type = __TRACE_LAST_TYPE + 1;
@@ -712,11 +712,8 @@ struct trace_event *ftrace_find_event(int type) { struct trace_event *event; struct hlist_node *n; - unsigned key; - key = type & (EVENT_HASHSIZE - 1); - - hlist_for_each_entry(event, n, &event_hash[key], node) { + hash_for_each_possible(event_hash, event, n, node, type) { if (event->type == type) return event; }
@@ -781,7 +778,6 @@ void trace_event_read_unlock(void) */ int register_ftrace_event(struct trace_event *event) { - unsigned key; int ret = 0; down_write(&trace_event_mutex);
@@ -833,9 +829,7 @@ int register_ftrace_event(struct trace_event *event) if (event->funcs->binary == NULL) event->funcs->binary = trace_nop_print; - key = event->type & (EVENT_HASHSIZE - 1); - - hlist_add_head(&event->node, &event_hash[key]); + hash_add(event_hash, &event->node, event->type); ret = event->type; out:
@@ -850,7 +844,7 @@ EXPORT_SYMBOL_GPL(register_ftrace_event); */ int __unregister_ftrace_event(struct trace_event *event) { - hlist_del(&event->node); + hash_del(&event->node); list_del(&event->list); return 0; }
@@ -1323,6 +1317,8 @@ __init static int init_events(void) } } + hash_init(event_hash); + return 0; } early_initcall(init_events);
--
1.7.8.6
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