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| author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-12-12 00:37:54 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-01-22 13:08:56 +0300 |
| commit | 2f0df49c89acaa58571d509830bc481250699885 (patch) | |
| tree | 828a30d85916fdf4a99202b3e89d37416d8684c1 | |
| parent | c7539258146844ebd8795c31275c720ded61bb84 (diff) | |
| download | linux-2f0df49c89acaa58571d509830bc481250699885.tar.xz | |
jump_label: Do not profile branch annotations
While running my branch profiler that checks for incorrect "likely" and
"unlikely"s around the kernel, there's a large number of them that are
incorrect due to being "static_branches".
As static_branches are rather special, as they are likely or unlikely for
other reasons than normal annotations are used for, there's no reason to
have them be profiled.
Expose the "unlikely_notrace" and "likely_notrace" so that the
static_branch can use them, and have them be ignored by the branch
profilers.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201211163754.585174b9@gandalf.local.home
| -rw-r--r-- | include/linux/compiler.h | 2 | ||||
| -rw-r--r-- | include/linux/jump_label.h | 12 |
2 files changed, 8 insertions, 6 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index b8fe0c23cfff..df5b405e6305 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -76,6 +76,8 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, #else # define likely(x) __builtin_expect(!!(x), 1) # define unlikely(x) __builtin_expect(!!(x), 0) +# define likely_notrace(x) likely(x) +# define unlikely_notrace(x) unlikely(x) #endif /* Optimization barrier */ diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index 32809624d422..d92691262f51 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -261,14 +261,14 @@ static __always_inline void jump_label_init(void) static __always_inline bool static_key_false(struct static_key *key) { - if (unlikely(static_key_count(key) > 0)) + if (unlikely_notrace(static_key_count(key) > 0)) return true; return false; } static __always_inline bool static_key_true(struct static_key *key) { - if (likely(static_key_count(key) > 0)) + if (likely_notrace(static_key_count(key) > 0)) return true; return false; } @@ -460,7 +460,7 @@ extern bool ____wrong_branch_error(void); branch = !arch_static_branch_jump(&(x)->key, true); \ else \ branch = ____wrong_branch_error(); \ - likely(branch); \ + likely_notrace(branch); \ }) #define static_branch_unlikely(x) \ @@ -472,13 +472,13 @@ extern bool ____wrong_branch_error(void); branch = arch_static_branch(&(x)->key, false); \ else \ branch = ____wrong_branch_error(); \ - unlikely(branch); \ + unlikely_notrace(branch); \ }) #else /* !CONFIG_JUMP_LABEL */ -#define static_branch_likely(x) likely(static_key_enabled(&(x)->key)) -#define static_branch_unlikely(x) unlikely(static_key_enabled(&(x)->key)) +#define static_branch_likely(x) likely_notrace(static_key_enabled(&(x)->key)) +#define static_branch_unlikely(x) unlikely_notrace(static_key_enabled(&(x)->key)) #endif /* CONFIG_JUMP_LABEL */ |