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authorSteven Rostedt <srostedt@redhat.com>2008-11-21 00:40:40 -0500
committerIngo Molnar <mingo@elte.hu>2008-11-23 11:39:56 +0100
commit45b797492a0758e64dff74e9db70e1f65e0603a5 (patch)
tree75db13ee888a6c7f90c92c17a743bff8ce42d86a
parent42f565e116e0408b5ddc21a33c4a4d41fd572420 (diff)
trace: consolidate unlikely and likely profiler
Impact: clean up to make one profiler of like and unlikely tracer The likely and unlikely profiler prints out the file and line numbers of the annotated branches that it is profiling. It shows the number of times it was correct or incorrect in its guess. Having two different files or sections for that matter to tell us if it was a likely or unlikely is pretty pointless. We really only care if it was correct or not. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--include/asm-generic/vmlinux.lds.h9
-rw-r--r--include/linux/compiler.h24
-rw-r--r--kernel/trace/Kconfig3
-rw-r--r--kernel/trace/trace_branch.c39
4 files changed, 22 insertions, 53 deletions
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 3b46ae46493..8bccb49981e 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -46,12 +46,9 @@
#endif
#ifdef CONFIG_TRACE_BRANCH_PROFILING
-#define LIKELY_PROFILE() VMLINUX_SYMBOL(__start_likely_profile) = .; \
- *(_ftrace_likely) \
- VMLINUX_SYMBOL(__stop_likely_profile) = .; \
- VMLINUX_SYMBOL(__start_unlikely_profile) = .; \
- *(_ftrace_unlikely) \
- VMLINUX_SYMBOL(__stop_unlikely_profile) = .;
+#define LIKELY_PROFILE() VMLINUX_SYMBOL(__start_annotated_branch_profile) = .; \
+ *(_ftrace_annotated_branch) \
+ VMLINUX_SYMBOL(__stop_annotated_branch_profile) = .;
#else
#define LIKELY_PROFILE()
#endif
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index c25e525121f..0628a2013fa 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -77,32 +77,18 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
#define likely_notrace(x) __builtin_expect(!!(x), 1)
#define unlikely_notrace(x) __builtin_expect(!!(x), 0)
-#define likely_check(x) ({ \
+#define __branch_check__(x, expect) ({ \
int ______r; \
static struct ftrace_branch_data \
__attribute__((__aligned__(4))) \
- __attribute__((section("_ftrace_likely"))) \
+ __attribute__((section("_ftrace_annotated_branch"))) \
______f = { \
.func = __func__, \
.file = __FILE__, \
.line = __LINE__, \
}; \
______r = likely_notrace(x); \
- ftrace_likely_update(&______f, ______r, 1); \
- ______r; \
- })
-#define unlikely_check(x) ({ \
- int ______r; \
- static struct ftrace_branch_data \
- __attribute__((__aligned__(4))) \
- __attribute__((section("_ftrace_unlikely"))) \
- ______f = { \
- .func = __func__, \
- .file = __FILE__, \
- .line = __LINE__, \
- }; \
- ______r = unlikely_notrace(x); \
- ftrace_likely_update(&______f, ______r, 0); \
+ ftrace_likely_update(&______f, ______r, expect); \
______r; \
})
@@ -112,10 +98,10 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
* written by Daniel Walker.
*/
# ifndef likely
-# define likely(x) (__builtin_constant_p(x) ? !!(x) : likely_check(x))
+# define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
# endif
# ifndef unlikely
-# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : unlikely_check(x))
+# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
# endif
#else
# define likely(x) __builtin_expect(!!(x), 1)
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index b8378fad29a..7e354870570 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -166,8 +166,7 @@ config TRACE_BRANCH_PROFILING
This tracer profiles all the the likely and unlikely macros
in the kernel. It will display the results in:
- /debugfs/tracing/profile_likely
- /debugfs/tracing/profile_unlikely
+ /debugfs/tracing/profile_annotated_branch
Note: this will add a significant overhead, only turn this
on if you need to profile the system's use of these macros.
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index 23f9b02ce96..21dedc8b50a 100644
--- a/kernel/trace/trace_branch.c
+++ b/kernel/trace/trace_branch.c
@@ -261,7 +261,7 @@ static struct seq_operations tracing_likely_seq_ops = {
.show = t_show,
};
-static int tracing_likely_open(struct inode *inode, struct file *file)
+static int tracing_branch_open(struct inode *inode, struct file *file)
{
int ret;
@@ -274,25 +274,18 @@ static int tracing_likely_open(struct inode *inode, struct file *file)
return ret;
}
-static struct file_operations tracing_likely_fops = {
- .open = tracing_likely_open,
+static const struct file_operations tracing_branch_fops = {
+ .open = tracing_branch_open,
.read = seq_read,
.llseek = seq_lseek,
};
-extern unsigned long __start_likely_profile[];
-extern unsigned long __stop_likely_profile[];
-extern unsigned long __start_unlikely_profile[];
-extern unsigned long __stop_unlikely_profile[];
+extern unsigned long __start_annotated_branch_profile[];
+extern unsigned long __stop_annotated_branch_profile[];
-static struct ftrace_pointer ftrace_likely_pos = {
- .start = __start_likely_profile,
- .stop = __stop_likely_profile,
-};
-
-static struct ftrace_pointer ftrace_unlikely_pos = {
- .start = __start_unlikely_profile,
- .stop = __stop_unlikely_profile,
+static const struct ftrace_pointer ftrace_annotated_branch_pos = {
+ .start = __start_annotated_branch_profile,
+ .stop = __stop_annotated_branch_profile,
};
static __init int ftrace_branch_init(void)
@@ -302,18 +295,12 @@ static __init int ftrace_branch_init(void)
d_tracer = tracing_init_dentry();
- entry = debugfs_create_file("profile_likely", 0444, d_tracer,
- &ftrace_likely_pos,
- &tracing_likely_fops);
- if (!entry)
- pr_warning("Could not create debugfs 'profile_likely' entry\n");
-
- entry = debugfs_create_file("profile_unlikely", 0444, d_tracer,
- &ftrace_unlikely_pos,
- &tracing_likely_fops);
+ entry = debugfs_create_file("profile_annotated_branch", 0444, d_tracer,
+ &ftrace_annotated_branch_pos,
+ &tracing_branch_fops);
if (!entry)
- pr_warning("Could not create debugfs"
- " 'profile_unlikely' entry\n");
+ pr_warning("Could not create debugfs "
+ "'profile_annotatet_branch' entry\n");
return 0;
}