The following commit has been merged into the locking/core branch of tip: Commit-ID: 2f0df49c89acaa58571d509830bc481250699885 Gitweb: https://git.kernel.org/tip/2f0df49c89acaa58571d509830bc481250699885 Author: Steven Rostedt (VMware) <rost...@goodmis.org> AuthorDate: Fri, 11 Dec 2020 16:37:54 -05:00 Committer: Peter Zijlstra <pet...@infradead.org> CommitterDate: Fri, 22 Jan 2021 11:08:56 +01:00
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) <rost...@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Link: https://lkml.kernel.org/r/20201211163754.58517...@gandalf.local.home --- include/linux/compiler.h | 2 ++ 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 b8fe0c2..df5b405 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 3280962..d926912 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 */
