[for-next][PATCH 1/8] tracing: Add ftrace_hash_key() helper function

From: Steven Rostedt
Date: Fri Feb 03 2017 - 08:42:49 EST


From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>

Replace the couple of use cases that has small logic to produce the ftrace
function key id with a helper function. No need for duplicate code.

Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
kernel/trace/ftrace.c | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 2d554a02241d..89240f62061c 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1185,6 +1185,15 @@ struct ftrace_page {
static struct ftrace_page *ftrace_pages_start;
static struct ftrace_page *ftrace_pages;

+static __always_inline unsigned long
+ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip)
+{
+ if (hash->size_bits > 0)
+ return hash_long(ip, hash->size_bits);
+
+ return 0;
+}
+
struct ftrace_func_entry *
ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
{
@@ -1195,11 +1204,7 @@ ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
if (ftrace_hash_empty(hash))
return NULL;

- if (hash->size_bits > 0)
- key = hash_long(ip, hash->size_bits);
- else
- key = 0;
-
+ key = ftrace_hash_key(hash, ip);
hhd = &hash->buckets[key];

hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
@@ -1215,11 +1220,7 @@ static void __add_hash_entry(struct ftrace_hash *hash,
struct hlist_head *hhd;
unsigned long key;

- if (hash->size_bits)
- key = hash_long(entry->ip, hash->size_bits);
- else
- key = 0;
-
+ key = ftrace_hash_key(hash, entry->ip);
hhd = &hash->buckets[key];
hlist_add_head(&entry->hlist, hhd);
hash->count++;
--
2.10.2