From: Lai Jiangshan <laijs@cn.fujitsu.com>
To: Steven Rostedt <srostedt@redhat.com>, Ingo Molnar <mingo@elte.hu>,
Frederic Weisbecker <fweisbec@gmail.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH] tracing: use union for multi-usages field
Date: Tue, 24 Mar 2009 13:38:06 +0800 [thread overview]
Message-ID: <49C871BE.3080405@cn.fujitsu.com> (raw)
Impact: cleanup
cleanup for readability.
struct dyn_ftrace::ip has different usages in his lifecycle,
we use union for it. And also for struct dyn_ftrace::flags.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index db3fed6..cdb0d3f 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -145,9 +145,15 @@ enum {
};
struct dyn_ftrace {
- unsigned long ip; /* address of mcount call-site */
- unsigned long flags;
- struct dyn_arch_ftrace arch;
+ union {
+ unsigned long ip; /* address of mcount call-site */
+ struct dyn_ftrace *freelist;
+ };
+ union {
+ unsigned long flags;
+ struct dyn_ftrace *newlist;
+ };
+ struct dyn_arch_ftrace arch;
};
int ftrace_force_update(void);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 7847806..2c578c5 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -339,7 +339,7 @@ static inline int record_frozen(struct dyn_ftrace *rec)
static void ftrace_free_rec(struct dyn_ftrace *rec)
{
- rec->ip = (unsigned long)ftrace_free_records;
+ rec->freelist = ftrace_free_records;
ftrace_free_records = rec;
rec->flags |= FTRACE_FL_FREE;
}
@@ -377,7 +377,7 @@ static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
return NULL;
}
- ftrace_free_records = (void *)rec->ip;
+ ftrace_free_records = rec->freelist;
memset(rec, 0, sizeof(*rec));
return rec;
}
@@ -409,7 +409,7 @@ ftrace_record_ip(unsigned long ip)
return NULL;
rec->ip = ip;
- rec->flags = (unsigned long)ftrace_new_addrs;
+ rec->newlist = ftrace_new_addrs;
ftrace_new_addrs = rec;
return rec;
@@ -729,7 +729,7 @@ static int ftrace_update_code(struct module *mod)
return -1;
p = ftrace_new_addrs;
- ftrace_new_addrs = (struct dyn_ftrace *)p->flags;
+ ftrace_new_addrs = p->newlist;
p->flags = 0L;
/* convert record (i.e, patch mcount-call with NOP) */
next reply other threads:[~2009-03-24 5:40 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-24 5:38 Lai Jiangshan [this message]
2009-03-24 15:48 ` [tip:tracing/ftrace] tracing: use union for multi-usages field Lai Jiangshan
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