ftrace: Remove record freezing
Masami Hiramatsu [Tue, 2 Feb 2010 21:49:25 +0000 (16:49 -0500)]
Remove record freezing. Because kprobes never puts probe on
ftrace's mcount call anymore, it doesn't need ftrace to check
whether kprobes on it.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: przemyslaw@pawelczyk.it
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100202214925.4694.73469.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/ftrace.h
kernel/trace/ftrace.c

index 9d127ef..eb054ae 100644 (file)
@@ -143,7 +143,6 @@ enum {
        FTRACE_FL_ENABLED       = (1 << 3),
        FTRACE_FL_NOTRACE       = (1 << 4),
        FTRACE_FL_CONVERTED     = (1 << 5),
-       FTRACE_FL_FROZEN        = (1 << 6),
 };
 
 struct dyn_ftrace {
index 3d90661..1904797 100644 (file)
@@ -22,7 +22,6 @@
 #include <linux/hardirq.h>
 #include <linux/kthread.h>
 #include <linux/uaccess.h>
-#include <linux/kprobes.h>
 #include <linux/ftrace.h>
 #include <linux/sysctl.h>
 #include <linux/ctype.h>
@@ -898,36 +897,6 @@ static struct dyn_ftrace *ftrace_free_records;
                }                               \
        }
 
-#ifdef CONFIG_KPROBES
-
-static int frozen_record_count;
-
-static inline void freeze_record(struct dyn_ftrace *rec)
-{
-       if (!(rec->flags & FTRACE_FL_FROZEN)) {
-               rec->flags |= FTRACE_FL_FROZEN;
-               frozen_record_count++;
-       }
-}
-
-static inline void unfreeze_record(struct dyn_ftrace *rec)
-{
-       if (rec->flags & FTRACE_FL_FROZEN) {
-               rec->flags &= ~FTRACE_FL_FROZEN;
-               frozen_record_count--;
-       }
-}
-
-static inline int record_frozen(struct dyn_ftrace *rec)
-{
-       return rec->flags & FTRACE_FL_FROZEN;
-}
-#else
-# define freeze_record(rec)                    ({ 0; })
-# define unfreeze_record(rec)                  ({ 0; })
-# define record_frozen(rec)                    ({ 0; })
-#endif /* CONFIG_KPROBES */
-
 static void ftrace_free_rec(struct dyn_ftrace *rec)
 {
        rec->freelist = ftrace_free_records;
@@ -1091,14 +1060,6 @@ static void ftrace_replace_code(int enable)
                    !(rec->flags & FTRACE_FL_CONVERTED))
                        continue;
 
-               /* ignore updates to this record's mcount site */
-               if (get_kprobe((void *)rec->ip)) {
-                       freeze_record(rec);
-                       continue;
-               } else {
-                       unfreeze_record(rec);
-               }
-
                failed = __ftrace_replace_code(rec, enable);
                if (failed) {
                        rec->flags |= FTRACE_FL_FAILED;