diff options
-rw-r--r-- | include/linux/compiler.h | 14 | ||||
-rw-r--r-- | kernel/trace/trace_branch.c | 6 |
2 files changed, 13 insertions, 7 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index cf0fa5d86059..bbbe1570de1c 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h | |||
@@ -107,12 +107,13 @@ struct ftrace_branch_data { | |||
107 | */ | 107 | */ |
108 | #if defined(CONFIG_TRACE_BRANCH_PROFILING) \ | 108 | #if defined(CONFIG_TRACE_BRANCH_PROFILING) \ |
109 | && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__) | 109 | && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__) |
110 | void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); | 110 | void ftrace_likely_update(struct ftrace_branch_data *f, int val, |
111 | int expect, int is_constant); | ||
111 | 112 | ||
112 | #define likely_notrace(x) __builtin_expect(!!(x), 1) | 113 | #define likely_notrace(x) __builtin_expect(!!(x), 1) |
113 | #define unlikely_notrace(x) __builtin_expect(!!(x), 0) | 114 | #define unlikely_notrace(x) __builtin_expect(!!(x), 0) |
114 | 115 | ||
115 | #define __branch_check__(x, expect) ({ \ | 116 | #define __branch_check__(x, expect, is_constant) ({ \ |
116 | int ______r; \ | 117 | int ______r; \ |
117 | static struct ftrace_branch_data \ | 118 | static struct ftrace_branch_data \ |
118 | __attribute__((__aligned__(4))) \ | 119 | __attribute__((__aligned__(4))) \ |
@@ -122,8 +123,9 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); | |||
122 | .file = __FILE__, \ | 123 | .file = __FILE__, \ |
123 | .line = __LINE__, \ | 124 | .line = __LINE__, \ |
124 | }; \ | 125 | }; \ |
125 | ______r = likely_notrace(x); \ | 126 | ______r = __builtin_expect(!!(x), expect); \ |
126 | ftrace_likely_update(&______f, ______r, expect); \ | 127 | ftrace_likely_update(&______f, ______r, \ |
128 | expect, is_constant); \ | ||
127 | ______r; \ | 129 | ______r; \ |
128 | }) | 130 | }) |
129 | 131 | ||
@@ -133,10 +135,10 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); | |||
133 | * written by Daniel Walker. | 135 | * written by Daniel Walker. |
134 | */ | 136 | */ |
135 | # ifndef likely | 137 | # ifndef likely |
136 | # define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1)) | 138 | # define likely(x) (__branch_check__(x, 1, __builtin_constant_p(x))) |
137 | # endif | 139 | # endif |
138 | # ifndef unlikely | 140 | # ifndef unlikely |
139 | # define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0)) | 141 | # define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x))) |
140 | # endif | 142 | # endif |
141 | 143 | ||
142 | #ifdef CONFIG_PROFILE_ALL_BRANCHES | 144 | #ifdef CONFIG_PROFILE_ALL_BRANCHES |
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c index 75489de546b6..7afe426ea528 100644 --- a/kernel/trace/trace_branch.c +++ b/kernel/trace/trace_branch.c | |||
@@ -200,8 +200,12 @@ void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) | |||
200 | } | 200 | } |
201 | #endif /* CONFIG_BRANCH_TRACER */ | 201 | #endif /* CONFIG_BRANCH_TRACER */ |
202 | 202 | ||
203 | void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect) | 203 | void ftrace_likely_update(struct ftrace_branch_data *f, int val, |
204 | int expect, int is_constant) | ||
204 | { | 205 | { |
206 | /* A constant is always correct */ | ||
207 | if (is_constant) | ||
208 | val = expect; | ||
205 | /* | 209 | /* |
206 | * I would love to have a trace point here instead, but the | 210 | * I would love to have a trace point here instead, but the |
207 | * trace point code is so inundated with unlikely and likely | 211 | * trace point code is so inundated with unlikely and likely |