From: Lai Jiangshan Date: Tue, 24 Mar 2009 05:38:06 +0000 (+0800) Subject: tracing: use union for multi-usages field X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=ee000b7f9fe429d2470c674ccec8d344f6789e0d;p=linux-2.6-omap-h63xx.git tracing: use union for multi-usages field Impact: cleanup 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 Cc: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <49C871BE.3080405@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 1141248c84e..015a3d22cf7 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 bb377112b1b..7b8722baf15 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -341,7 +341,7 @@ 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; } @@ -379,7 +379,7 @@ 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; } @@ -411,7 +411,7 @@ 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; @@ -731,7 +731,7 @@ 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) */