ftrace: remove struct list_head from struct dyn_ftrace
Impact: save memory
The struct dyn_ftrace table is very large, this patch will save
about 50%.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <srostedt@redhat.com>
LKML-Reference: <49BA2C9F.8020009@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index bf78a4c..90d5729 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -272,7 +272,7 @@
static int ftrace_filtered;
-static LIST_HEAD(ftrace_new_addrs);
+static struct dyn_ftrace *ftrace_new_addrs;
static DEFINE_MUTEX(ftrace_regex_lock);
@@ -409,8 +409,8 @@
return NULL;
rec->ip = ip;
-
- list_add(&rec->list, &ftrace_new_addrs);
+ rec->flags = (unsigned long)ftrace_new_addrs;
+ ftrace_new_addrs = rec;
return rec;
}
@@ -716,19 +716,21 @@
static int ftrace_update_code(struct module *mod)
{
- struct dyn_ftrace *p, *t;
+ struct dyn_ftrace *p;
cycle_t start, stop;
start = ftrace_now(raw_smp_processor_id());
ftrace_update_cnt = 0;
- list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) {
+ while (ftrace_new_addrs) {
/* If something went wrong, bail without enabling anything */
if (unlikely(ftrace_disabled))
return -1;
- list_del_init(&p->list);
+ p = ftrace_new_addrs;
+ ftrace_new_addrs = (struct dyn_ftrace *)p->flags;
+ p->flags = 0L;
/* convert record (i.e, patch mcount-call with NOP) */
if (ftrace_code_disable(mod, p)) {
