diff --git a/tools/perf/bench/bench.h b/tools/perf/bench/bench.h
index 7e7e43207bbd..579a592990dd 100644
--- a/tools/perf/bench/bench.h
+++ b/tools/perf/bench/bench.h
@@ -25,19 +25,17 @@
 # endif
 #endif
 
-extern int bench_numa(int argc, const char **argv, const char *prefix);
-extern int bench_sched_messaging(int argc, const char **argv, const char *prefix);
-extern int bench_sched_pipe(int argc, const char **argv, const char *prefix);
-extern int bench_mem_memcpy(int argc, const char **argv,
-			    const char *prefix);
-extern int bench_mem_memset(int argc, const char **argv, const char *prefix);
-extern int bench_futex_hash(int argc, const char **argv, const char *prefix);
-extern int bench_futex_wake(int argc, const char **argv, const char *prefix);
-extern int bench_futex_wake_parallel(int argc, const char **argv,
-				     const char *prefix);
-extern int bench_futex_requeue(int argc, const char **argv, const char *prefix);
+int bench_numa(int argc, const char **argv, const char *prefix);
+int bench_sched_messaging(int argc, const char **argv, const char *prefix);
+int bench_sched_pipe(int argc, const char **argv, const char *prefix);
+int bench_mem_memcpy(int argc, const char **argv, const char *prefix);
+int bench_mem_memset(int argc, const char **argv, const char *prefix);
+int bench_futex_hash(int argc, const char **argv, const char *prefix);
+int bench_futex_wake(int argc, const char **argv, const char *prefix);
+int bench_futex_wake_parallel(int argc, const char **argv, const char *prefix);
+int bench_futex_requeue(int argc, const char **argv, const char *prefix);
 /* pi futexes */
-extern int bench_futex_lock_pi(int argc, const char **argv, const char *prefix);
+int bench_futex_lock_pi(int argc, const char **argv, const char *prefix);
 
 #define BENCH_FORMAT_DEFAULT_STR	"default"
 #define BENCH_FORMAT_DEFAULT		0
diff --git a/tools/perf/bench/mem-memcpy-arch.h b/tools/perf/bench/mem-memcpy-arch.h
index 57b4ed871459..5aad2a9408b0 100644
--- a/tools/perf/bench/mem-memcpy-arch.h
+++ b/tools/perf/bench/mem-memcpy-arch.h
@@ -2,7 +2,7 @@
 #ifdef HAVE_ARCH_X86_64_SUPPORT
 
 #define MEMCPY_FN(fn, name, desc)		\
-	extern void *fn(void *, const void *, size_t);
+	void *fn(void *, const void *, size_t);
 
 #include "mem-memcpy-x86-64-asm-def.h"
 
diff --git a/tools/perf/bench/mem-memset-arch.h b/tools/perf/bench/mem-memset-arch.h
index 633800cb0dcb..0d15786d9ae3 100644
--- a/tools/perf/bench/mem-memset-arch.h
+++ b/tools/perf/bench/mem-memset-arch.h
@@ -2,7 +2,7 @@
 #ifdef HAVE_ARCH_X86_64_SUPPORT
 
 #define MEMSET_FN(fn, name, desc)		\
-	extern void *fn(void *, int, size_t);
+	void *fn(void *, int, size_t);
 
 #include "mem-memset-x86-64-asm-def.h"
 
diff --git a/tools/perf/builtin.h b/tools/perf/builtin.h
index 3f871b54e261..41c24010ab43 100644
--- a/tools/perf/builtin.h
+++ b/tools/perf/builtin.h
@@ -7,38 +7,38 @@
 extern const char perf_usage_string[];
 extern const char perf_more_info_string[];
 
-extern void list_common_cmds_help(void);
-extern const char *help_unknown_cmd(const char *cmd);
-extern void prune_packed_objects(int);
-extern int read_line_with_nul(char *buf, int size, FILE *file);
-extern int check_pager_config(const char *cmd);
+void list_common_cmds_help(void);
+const char *help_unknown_cmd(const char *cmd);
+void prune_packed_objects(int);
+int read_line_with_nul(char *buf, int size, FILE *file);
+int check_pager_config(const char *cmd);
 
-extern int cmd_annotate(int argc, const char **argv, const char *prefix);
-extern int cmd_bench(int argc, const char **argv, const char *prefix);
-extern int cmd_buildid_cache(int argc, const char **argv, const char *prefix);
-extern int cmd_buildid_list(int argc, const char **argv, const char *prefix);
-extern int cmd_config(int argc, const char **argv, const char *prefix);
-extern int cmd_diff(int argc, const char **argv, const char *prefix);
-extern int cmd_evlist(int argc, const char **argv, const char *prefix);
-extern int cmd_help(int argc, const char **argv, const char *prefix);
-extern int cmd_sched(int argc, const char **argv, const char *prefix);
-extern int cmd_list(int argc, const char **argv, const char *prefix);
-extern int cmd_record(int argc, const char **argv, const char *prefix);
-extern int cmd_report(int argc, const char **argv, const char *prefix);
-extern int cmd_stat(int argc, const char **argv, const char *prefix);
-extern int cmd_timechart(int argc, const char **argv, const char *prefix);
-extern int cmd_top(int argc, const char **argv, const char *prefix);
-extern int cmd_script(int argc, const char **argv, const char *prefix);
-extern int cmd_version(int argc, const char **argv, const char *prefix);
-extern int cmd_probe(int argc, const char **argv, const char *prefix);
-extern int cmd_kmem(int argc, const char **argv, const char *prefix);
-extern int cmd_lock(int argc, const char **argv, const char *prefix);
-extern int cmd_kvm(int argc, const char **argv, const char *prefix);
-extern int cmd_test(int argc, const char **argv, const char *prefix);
-extern int cmd_trace(int argc, const char **argv, const char *prefix);
-extern int cmd_inject(int argc, const char **argv, const char *prefix);
-extern int cmd_mem(int argc, const char **argv, const char *prefix);
-extern int cmd_data(int argc, const char **argv, const char *prefix);
+int cmd_annotate(int argc, const char **argv, const char *prefix);
+int cmd_bench(int argc, const char **argv, const char *prefix);
+int cmd_buildid_cache(int argc, const char **argv, const char *prefix);
+int cmd_buildid_list(int argc, const char **argv, const char *prefix);
+int cmd_config(int argc, const char **argv, const char *prefix);
+int cmd_diff(int argc, const char **argv, const char *prefix);
+int cmd_evlist(int argc, const char **argv, const char *prefix);
+int cmd_help(int argc, const char **argv, const char *prefix);
+int cmd_sched(int argc, const char **argv, const char *prefix);
+int cmd_list(int argc, const char **argv, const char *prefix);
+int cmd_record(int argc, const char **argv, const char *prefix);
+int cmd_report(int argc, const char **argv, const char *prefix);
+int cmd_stat(int argc, const char **argv, const char *prefix);
+int cmd_timechart(int argc, const char **argv, const char *prefix);
+int cmd_top(int argc, const char **argv, const char *prefix);
+int cmd_script(int argc, const char **argv, const char *prefix);
+int cmd_version(int argc, const char **argv, const char *prefix);
+int cmd_probe(int argc, const char **argv, const char *prefix);
+int cmd_kmem(int argc, const char **argv, const char *prefix);
+int cmd_lock(int argc, const char **argv, const char *prefix);
+int cmd_kvm(int argc, const char **argv, const char *prefix);
+int cmd_test(int argc, const char **argv, const char *prefix);
+int cmd_trace(int argc, const char **argv, const char *prefix);
+int cmd_inject(int argc, const char **argv, const char *prefix);
+int cmd_mem(int argc, const char **argv, const char *prefix);
+int cmd_data(int argc, const char **argv, const char *prefix);
 
-extern int find_scripts(char **scripts_array, char **scripts_path_array);
+int find_scripts(char **scripts_array, char **scripts_path_array);
 #endif
diff --git a/tools/perf/util/cache.h b/tools/perf/util/cache.h
index 3ca453f0c51f..17be38540404 100644
--- a/tools/perf/util/cache.h
+++ b/tools/perf/util/cache.h
@@ -26,14 +26,14 @@
 extern const char *config_exclusive_filename;
 
 typedef int (*config_fn_t)(const char *, const char *, void *);
-extern int perf_default_config(const char *, const char *, void *);
-extern int perf_config(config_fn_t fn, void *);
-extern int perf_config_int(const char *, const char *);
-extern u64 perf_config_u64(const char *, const char *);
-extern int perf_config_bool(const char *, const char *);
-extern int config_error_nonbool(const char *);
-extern const char *perf_config_dirname(const char *, const char *);
-extern const char *perf_etc_perfconfig(void);
+int perf_default_config(const char *, const char *, void *);
+int perf_config(config_fn_t fn, void *);
+int perf_config_int(const char *, const char *);
+u64 perf_config_u64(const char *, const char *);
+int perf_config_bool(const char *, const char *);
+int config_error_nonbool(const char *);
+const char *perf_config_dirname(const char *, const char *);
+const char *perf_etc_perfconfig(void);
 
 char *alias_lookup(const char *alias);
 int split_cmdline(char *cmdline, const char ***argv);
@@ -67,10 +67,10 @@ static inline int is_absolute_path(const char *path)
 const char *make_nonrelative_path(const char *path);
 char *strip_path_suffix(const char *path, const char *suffix);
 
-extern char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
-extern char *perf_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
+char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
+char *perf_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 
-extern char *perf_pathdup(const char *fmt, ...)
+char *perf_pathdup(const char *fmt, ...)
 	__attribute__((format (printf, 1, 2)));
 
 #endif /* __PERF_CACHE_H */
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index 18dd22269764..d2a9e694810c 100644
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -220,7 +220,7 @@ int fill_callchain_info(struct addr_location *al, struct callchain_cursor_node *
 			bool hide_unresolved);
 
 extern const char record_callchain_help[];
-extern int parse_callchain_record(const char *arg, struct callchain_param *param);
+int parse_callchain_record(const char *arg, struct callchain_param *param);
 int parse_callchain_record_opt(const char *arg, struct callchain_param *param);
 int parse_callchain_report_opt(const char *arg);
 int parse_callchain_top_opt(const char *arg);
@@ -236,7 +236,7 @@ static inline void callchain_cursor_snapshot(struct callchain_cursor *dest,
 }
 
 #ifdef HAVE_SKIP_CALLCHAIN_IDX
-extern int arch_skip_callchain_idx(struct thread *thread, struct ip_callchain *chain);
+int arch_skip_callchain_idx(struct thread *thread, struct ip_callchain *chain);
 #else
 static inline int arch_skip_callchain_idx(struct thread *thread __maybe_unused,
 			struct ip_callchain *chain __maybe_unused)
diff --git a/tools/perf/util/cgroup.h b/tools/perf/util/cgroup.h
index b4b8cb42fe5e..31f8dcdbd7ef 100644
--- a/tools/perf/util/cgroup.h
+++ b/tools/perf/util/cgroup.h
@@ -13,7 +13,7 @@ struct cgroup_sel {
 
 
 extern int nr_cgroups; /* number of explicit cgroups defined */
-extern void close_cgroup(struct cgroup_sel *cgrp);
-extern int parse_cgroups(const struct option *opt, const char *str, int unset);
+void close_cgroup(struct cgroup_sel *cgrp);
+int parse_cgroups(const struct option *opt, const char *str, int unset);
 
 #endif /* __CGROUP_H__ */
diff --git a/tools/perf/util/cloexec.h b/tools/perf/util/cloexec.h
index 3bee6773ddb0..d0d465953d36 100644
--- a/tools/perf/util/cloexec.h
+++ b/tools/perf/util/cloexec.h
@@ -5,7 +5,7 @@ unsigned long perf_event_open_cloexec_flag(void);
 
 #ifdef __GLIBC_PREREQ
 #if !__GLIBC_PREREQ(2, 6) && !defined(__UCLIBC__)
-extern int sched_getcpu(void) __THROW;
+int sched_getcpu(void) __THROW;
 #endif
 #endif
 
diff --git a/tools/perf/util/dwarf-aux.h b/tools/perf/util/dwarf-aux.h
index c42ec366f2a7..dc0ce1adb075 100644
--- a/tools/perf/util/dwarf-aux.h
+++ b/tools/perf/util/dwarf-aux.h
@@ -25,48 +25,48 @@
 #include <elfutils/version.h>
 
 /* Find the realpath of the target file */
-extern const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname);
+const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname);
 
 /* Get DW_AT_comp_dir (should be NULL with older gcc) */
-extern const char *cu_get_comp_dir(Dwarf_Die *cu_die);
+const char *cu_get_comp_dir(Dwarf_Die *cu_die);
 
 /* Get a line number and file name for given address */
-extern int cu_find_lineinfo(Dwarf_Die *cudie, unsigned long addr,
-			    const char **fname, int *lineno);
+int cu_find_lineinfo(Dwarf_Die *cudie, unsigned long addr,
+		     const char **fname, int *lineno);
 
 /* Walk on funcitons at given address */
-extern int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
-			int (*callback)(Dwarf_Die *, void *), void *data);
+int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
+			 int (*callback)(Dwarf_Die *, void *), void *data);
 
 /* Ensure that this DIE is a subprogram and definition (not declaration) */
-extern bool die_is_func_def(Dwarf_Die *dw_die);
+bool die_is_func_def(Dwarf_Die *dw_die);
 
 /* Ensure that this DIE is an instance of a subprogram */
-extern bool die_is_func_instance(Dwarf_Die *dw_die);
+bool die_is_func_instance(Dwarf_Die *dw_die);
 
 /* Compare diename and tname */
-extern bool die_compare_name(Dwarf_Die *dw_die, const char *tname);
+bool die_compare_name(Dwarf_Die *dw_die, const char *tname);
 
 /* Matching diename with glob pattern */
-extern bool die_match_name(Dwarf_Die *dw_die, const char *glob);
+bool die_match_name(Dwarf_Die *dw_die, const char *glob);
 
 /* Get callsite line number of inline-function instance */
-extern int die_get_call_lineno(Dwarf_Die *in_die);
+int die_get_call_lineno(Dwarf_Die *in_die);
 
 /* Get callsite file name of inlined function instance */
-extern const char *die_get_call_file(Dwarf_Die *in_die);
+const char *die_get_call_file(Dwarf_Die *in_die);
 
 /* Get type die */
-extern Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem);
+Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem);
 
 /* Get a type die, but skip qualifiers and typedef */
-extern Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem);
+Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem);
 
 /* Check whether the DIE is signed or not */
-extern bool die_is_signed_type(Dwarf_Die *tp_die);
+bool die_is_signed_type(Dwarf_Die *tp_die);
 
 /* Get data_member_location offset */
-extern int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs);
+int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs);
 
 /* Return values for die_find_child() callbacks */
 enum {
@@ -77,29 +77,29 @@ enum {
 };
 
 /* Search child DIEs */
-extern Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
-				 int (*callback)(Dwarf_Die *, void *),
-				 void *data, Dwarf_Die *die_mem);
+Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
+			 int (*callback)(Dwarf_Die *, void *),
+			 void *data, Dwarf_Die *die_mem);
 
 /* Search a non-inlined function including given address */
-extern Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
-				    Dwarf_Die *die_mem);
+Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
+			     Dwarf_Die *die_mem);
 
 /* Search a non-inlined function with tail call at given address */
 Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
 				    Dwarf_Die *die_mem);
 
 /* Search the top inlined function including given address */
-extern Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
-					  Dwarf_Die *die_mem);
+Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
+				   Dwarf_Die *die_mem);
 
 /* Search the deepest inlined function including given address */
-extern Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
-				      Dwarf_Die *die_mem);
+Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
+			       Dwarf_Die *die_mem);
 
 /* Walk on the instances of given DIE */
-extern int die_walk_instances(Dwarf_Die *in_die,
-			      int (*callback)(Dwarf_Die *, void *), void *data);
+int die_walk_instances(Dwarf_Die *in_die,
+		       int (*callback)(Dwarf_Die *, void *), void *data);
 
 /* Walker on lines (Note: line number will not be sorted) */
 typedef int (* line_walk_callback_t) (const char *fname, int lineno,
@@ -109,22 +109,20 @@ typedef int (* line_walk_callback_t) (const char *fname, int lineno,
  * Walk on lines inside given DIE. If the DIE is a subprogram, walk only on
  * the lines inside the subprogram, otherwise the DIE must be a CU DIE.
  */
-extern int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback,
-			  void *data);
+int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data);
 
 /* Find a variable called 'name' at given address */
-extern Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
-				       Dwarf_Addr addr, Dwarf_Die *die_mem);
+Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
+				Dwarf_Addr addr, Dwarf_Die *die_mem);
 
 /* Find a member called 'name' */
-extern Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
-				  Dwarf_Die *die_mem);
+Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
+			   Dwarf_Die *die_mem);
 
 /* Get the name of given variable DIE */
-extern int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf);
+int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf);
 
 /* Get the name and type of given variable DIE, stored as "type\tname" */
-extern int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf);
-extern int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
-			struct strbuf *buf);
+int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf);
+int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf);
 #endif
diff --git a/tools/perf/util/genelf.h b/tools/perf/util/genelf.h
index 45bf9c6d3257..cd67e64a0494 100644
--- a/tools/perf/util/genelf.h
+++ b/tools/perf/util/genelf.h
@@ -2,12 +2,10 @@
 #define __GENELF_H__
 
 /* genelf.c */
-extern int jit_write_elf(int fd, uint64_t code_addr, const char *sym,
-			 const void *code, int csize,
-			 void *debug, int nr_debug_entries);
+int jit_write_elf(int fd, uint64_t code_addr, const char *sym,
+		  const void *code, int csize, void *debug, int nr_debug_entries);
 /* genelf_debug.c */
-extern int jit_add_debug_info(Elf *e, uint64_t code_addr,
-			      void *debug, int nr_debug_entries);
+int jit_add_debug_info(Elf *e, uint64_t code_addr, void *debug, int nr_debug_entries);
 
 #if   defined(__arm__)
 #define GEN_ELF_ARCH	EM_ARM
diff --git a/tools/perf/util/jit.h b/tools/perf/util/jit.h
index a1e99da0715a..3f42ee4d2a0b 100644
--- a/tools/perf/util/jit.h
+++ b/tools/perf/util/jit.h
@@ -3,13 +3,9 @@
 
 #include <data.h>
 
-extern int jit_process(struct perf_session *session,
-		       struct perf_data_file *output,
-		       struct machine *machine,
-		       char *filename,
-		       pid_t pid,
-		       u64 *nbytes);
+int jit_process(struct perf_session *session, struct perf_data_file *output,
+		struct machine *machine, char *filename, pid_t pid, u64 *nbytes);
 
-extern int jit_inject_record(const char *filename);
+int jit_inject_record(const char *filename);
 
 #endif /* __JIT_H__ */
diff --git a/tools/perf/util/llvm-utils.h b/tools/perf/util/llvm-utils.h
index 5b3cf1c229e2..23b9a743fe72 100644
--- a/tools/perf/util/llvm-utils.h
+++ b/tools/perf/util/llvm-utils.h
@@ -39,11 +39,10 @@ struct llvm_param {
 };
 
 extern struct llvm_param llvm_param;
-extern int perf_llvm_config(const char *var, const char *value);
+int perf_llvm_config(const char *var, const char *value);
 
-extern int llvm__compile_bpf(const char *path, void **p_obj_buf,
-			     size_t *p_obj_buf_sz);
+int llvm__compile_bpf(const char *path, void **p_obj_buf, size_t *p_obj_buf_sz);
 
 /* This function is for test__llvm() use only */
-extern int llvm__search_clang(void);
+int llvm__search_clang(void);
 #endif
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 67e493088e81..d740c3ca9a1d 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -22,19 +22,18 @@ struct tracepoint_path {
 	struct tracepoint_path *next;
 };
 
-extern struct tracepoint_path *tracepoint_id_to_path(u64 config);
-extern struct tracepoint_path *tracepoint_name_to_path(const char *name);
-extern bool have_tracepoints(struct list_head *evlist);
+struct tracepoint_path *tracepoint_id_to_path(u64 config);
+struct tracepoint_path *tracepoint_name_to_path(const char *name);
+bool have_tracepoints(struct list_head *evlist);
 
 const char *event_type(int type);
 
-extern int parse_events_option(const struct option *opt, const char *str,
-			       int unset);
-extern int parse_events(struct perf_evlist *evlist, const char *str,
-			struct parse_events_error *error);
-extern int parse_events_terms(struct list_head *terms, const char *str);
-extern int parse_filter(const struct option *opt, const char *str, int unset);
-extern int exclude_perf(const struct option *opt, const char *arg, int unset);
+int parse_events_option(const struct option *opt, const char *str, int unset);
+int parse_events(struct perf_evlist *evlist, const char *str,
+		 struct parse_events_error *error);
+int parse_events_terms(struct list_head *terms, const char *str);
+int parse_filter(const struct option *opt, const char *str, int unset);
+int exclude_perf(const struct option *opt, const char *arg, int unset);
 
 #define EVENTS_HELP_MAX (128*1024)
 
@@ -183,7 +182,7 @@ void print_symbol_events(const char *event_glob, unsigned type,
 void print_tracepoint_events(const char *subsys_glob, const char *event_glob,
 			     bool name_only);
 int print_hwcache_events(const char *event_glob, bool name_only);
-extern int is_valid_tracepoint(const char *event_string);
+int is_valid_tracepoint(const char *event_string);
 
 int valid_event_mount(const char *eventfs);
 char *parse_events_formats_error_string(char *additional_terms);
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index ba926c30f8cd..e54e7b011577 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -114,49 +114,44 @@ int init_probe_symbol_maps(bool user_only);
 void exit_probe_symbol_maps(void);
 
 /* Command string to events */
-extern int parse_perf_probe_command(const char *cmd,
-				    struct perf_probe_event *pev);
-extern int parse_probe_trace_command(const char *cmd,
-				     struct probe_trace_event *tev);
+int parse_perf_probe_command(const char *cmd, struct perf_probe_event *pev);
+int parse_probe_trace_command(const char *cmd, struct probe_trace_event *tev);
 
 /* Events to command string */
-extern char *synthesize_perf_probe_command(struct perf_probe_event *pev);
-extern char *synthesize_probe_trace_command(struct probe_trace_event *tev);
-extern int synthesize_perf_probe_arg(struct perf_probe_arg *pa, char *buf,
-				     size_t len);
+char *synthesize_perf_probe_command(struct perf_probe_event *pev);
+char *synthesize_probe_trace_command(struct probe_trace_event *tev);
+int synthesize_perf_probe_arg(struct perf_probe_arg *pa, char *buf, size_t len);
 
 /* Check the perf_probe_event needs debuginfo */
-extern bool perf_probe_event_need_dwarf(struct perf_probe_event *pev);
+bool perf_probe_event_need_dwarf(struct perf_probe_event *pev);
 
 /* Release event contents */
-extern void clear_perf_probe_event(struct perf_probe_event *pev);
-extern void clear_probe_trace_event(struct probe_trace_event *tev);
+void clear_perf_probe_event(struct perf_probe_event *pev);
+void clear_probe_trace_event(struct probe_trace_event *tev);
 
 /* Command string to line-range */
-extern int parse_line_range_desc(const char *cmd, struct line_range *lr);
+int parse_line_range_desc(const char *cmd, struct line_range *lr);
 
 /* Release line range members */
-extern void line_range__clear(struct line_range *lr);
+void line_range__clear(struct line_range *lr);
 
 /* Initialize line range */
-extern int line_range__init(struct line_range *lr);
+int line_range__init(struct line_range *lr);
 
-extern int add_perf_probe_events(struct perf_probe_event *pevs, int npevs);
-extern int convert_perf_probe_events(struct perf_probe_event *pevs, int npevs);
-extern int apply_perf_probe_events(struct perf_probe_event *pevs, int npevs);
-extern void cleanup_perf_probe_events(struct perf_probe_event *pevs, int npevs);
-extern int del_perf_probe_events(struct strfilter *filter);
+int add_perf_probe_events(struct perf_probe_event *pevs, int npevs);
+int convert_perf_probe_events(struct perf_probe_event *pevs, int npevs);
+int apply_perf_probe_events(struct perf_probe_event *pevs, int npevs);
+void cleanup_perf_probe_events(struct perf_probe_event *pevs, int npevs);
+int del_perf_probe_events(struct strfilter *filter);
 
-extern int show_perf_probe_event(const char *group, const char *event,
-				 struct perf_probe_event *pev,
-				 const char *module, bool use_stdout);
-extern int show_perf_probe_events(struct strfilter *filter);
-extern int show_line_range(struct line_range *lr, const char *module,
-			   bool user);
-extern int show_available_vars(struct perf_probe_event *pevs, int npevs,
-			       struct strfilter *filter);
-extern int show_available_funcs(const char *module, struct strfilter *filter,
-				bool user);
+int show_perf_probe_event(const char *group, const char *event,
+			  struct perf_probe_event *pev,
+			  const char *module, bool use_stdout);
+int show_perf_probe_events(struct strfilter *filter);
+int show_line_range(struct line_range *lr, const char *module, bool user);
+int show_available_vars(struct perf_probe_event *pevs, int npevs,
+			struct strfilter *filter);
+int show_available_funcs(const char *module, struct strfilter *filter, bool user);
 bool arch__prefers_symtab(void);
 void arch__fix_tev_from_maps(struct perf_probe_event *pev,
 			     struct probe_trace_event *tev, struct map *map);
diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
index 0aec7704e395..51137fccb9c8 100644
--- a/tools/perf/util/probe-finder.h
+++ b/tools/perf/util/probe-finder.h
@@ -34,27 +34,25 @@ struct debuginfo {
 };
 
 /* This also tries to open distro debuginfo */
-extern struct debuginfo *debuginfo__new(const char *path);
-extern void debuginfo__delete(struct debuginfo *dbg);
+struct debuginfo *debuginfo__new(const char *path);
+void debuginfo__delete(struct debuginfo *dbg);
 
 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
-extern int debuginfo__find_trace_events(struct debuginfo *dbg,
-					struct perf_probe_event *pev,
-					struct probe_trace_event **tevs);
+int debuginfo__find_trace_events(struct debuginfo *dbg,
+				 struct perf_probe_event *pev,
+				 struct probe_trace_event **tevs);
 
 /* Find a perf_probe_point from debuginfo */
-extern int debuginfo__find_probe_point(struct debuginfo *dbg,
-				       unsigned long addr,
-				       struct perf_probe_point *ppt);
+int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
+				struct perf_probe_point *ppt);
 
 /* Find a line range */
-extern int debuginfo__find_line_range(struct debuginfo *dbg,
-				      struct line_range *lr);
+int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr);
 
 /* Find available variables */
-extern int debuginfo__find_available_vars_at(struct debuginfo *dbg,
-					     struct perf_probe_event *pev,
-					     struct variable_list **vls);
+int debuginfo__find_available_vars_at(struct debuginfo *dbg,
+				      struct perf_probe_event *pev,
+				      struct variable_list **vls);
 
 /* Find a src file from a DWARF tag path */
 int get_real_path(const char *raw_path, const char *comp_dir,
diff --git a/tools/perf/util/quote.h b/tools/perf/util/quote.h
index 172889ea234f..3340c9c4a6ca 100644
--- a/tools/perf/util/quote.h
+++ b/tools/perf/util/quote.h
@@ -24,6 +24,6 @@
  * sq_quote() in a real application.
  */
 
-extern void sq_quote_argv(struct strbuf *, const char **argv, size_t maxlen);
+void sq_quote_argv(struct strbuf *, const char **argv, size_t maxlen);
 
 #endif /* __PERF_QUOTE_H */
diff --git a/tools/perf/util/strbuf.h b/tools/perf/util/strbuf.h
index 7a32c838884d..b73cbaaf93bc 100644
--- a/tools/perf/util/strbuf.h
+++ b/tools/perf/util/strbuf.h
@@ -51,16 +51,16 @@ struct strbuf {
 #define STRBUF_INIT  { 0, 0, strbuf_slopbuf }
 
 /*----- strbuf life cycle -----*/
-extern void strbuf_init(struct strbuf *buf, ssize_t hint);
-extern void strbuf_release(struct strbuf *);
-extern char *strbuf_detach(struct strbuf *, size_t *);
+void strbuf_init(struct strbuf *buf, ssize_t hint);
+void strbuf_release(struct strbuf *buf);
+char *strbuf_detach(struct strbuf *buf, size_t *);
 
 /*----- strbuf size related -----*/
 static inline ssize_t strbuf_avail(const struct strbuf *sb) {
 	return sb->alloc ? sb->alloc - sb->len - 1 : 0;
 }
 
-extern void strbuf_grow(struct strbuf *, size_t);
+void strbuf_grow(struct strbuf *buf, size_t);
 
 static inline void strbuf_setlen(struct strbuf *sb, size_t len) {
 	if (!sb->alloc)
@@ -77,16 +77,16 @@ static inline void strbuf_addch(struct strbuf *sb, int c) {
 	sb->buf[sb->len] = '\0';
 }
 
-extern void strbuf_add(struct strbuf *, const void *, size_t);
+void strbuf_add(struct strbuf *buf, const void *, size_t);
 static inline void strbuf_addstr(struct strbuf *sb, const char *s) {
 	strbuf_add(sb, s, strlen(s));
 }
 
 __attribute__((format(printf,2,3)))
-extern void strbuf_addf(struct strbuf *sb, const char *fmt, ...);
-extern void strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap);
+void strbuf_addf(struct strbuf *sb, const char *fmt, ...);
+void strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap);
 
 /* XXX: if read fails, any partial read is undone */
-extern ssize_t strbuf_read(struct strbuf *, int fd, ssize_t hint);
+ssize_t strbuf_read(struct strbuf *, int fd, ssize_t hint);
 
 #endif /* __PERF_STRBUF_H */
diff --git a/tools/perf/util/svghelper.h b/tools/perf/util/svghelper.h
index 9292a5291445..946fdf2db97c 100644
--- a/tools/perf/util/svghelper.h
+++ b/tools/perf/util/svghelper.h
@@ -3,32 +3,31 @@
 
 #include <linux/types.h>
 
-extern void open_svg(const char *filename, int cpus, int rows, u64 start, u64 end);
-extern void svg_ubox(int Yslot, u64 start, u64 end, double height, const char *type, int fd, int err, int merges);
-extern void svg_lbox(int Yslot, u64 start, u64 end, double height, const char *type, int fd, int err, int merges);
-extern void svg_fbox(int Yslot, u64 start, u64 end, double height, const char *type, int fd, int err, int merges);
-extern void svg_box(int Yslot, u64 start, u64 end, const char *type);
-extern void svg_blocked(int Yslot, int cpu, u64 start, u64 end, const char *backtrace);
-extern void svg_running(int Yslot, int cpu, u64 start, u64 end, const char *backtrace);
-extern void svg_waiting(int Yslot, int cpu, u64 start, u64 end, const char *backtrace);
-extern void svg_cpu_box(int cpu, u64 max_frequency, u64 turbo_frequency);
+void open_svg(const char *filename, int cpus, int rows, u64 start, u64 end);
+void svg_ubox(int Yslot, u64 start, u64 end, double height, const char *type, int fd, int err, int merges);
+void svg_lbox(int Yslot, u64 start, u64 end, double height, const char *type, int fd, int err, int merges);
+void svg_fbox(int Yslot, u64 start, u64 end, double height, const char *type, int fd, int err, int merges);
+void svg_box(int Yslot, u64 start, u64 end, const char *type);
+void svg_blocked(int Yslot, int cpu, u64 start, u64 end, const char *backtrace);
+void svg_running(int Yslot, int cpu, u64 start, u64 end, const char *backtrace);
+void svg_waiting(int Yslot, int cpu, u64 start, u64 end, const char *backtrace);
+void svg_cpu_box(int cpu, u64 max_frequency, u64 turbo_frequency);
 
 
-extern void svg_process(int cpu, u64 start, u64 end, int pid, const char *name, const char *backtrace);
-extern void svg_cstate(int cpu, u64 start, u64 end, int type);
-extern void svg_pstate(int cpu, u64 start, u64 end, u64 freq);
+void svg_process(int cpu, u64 start, u64 end, int pid, const char *name, const char *backtrace);
+void svg_cstate(int cpu, u64 start, u64 end, int type);
+void svg_pstate(int cpu, u64 start, u64 end, u64 freq);
 
 
-extern void svg_time_grid(double min_thickness);
-extern void svg_io_legenda(void);
-extern void svg_legenda(void);
-extern void svg_wakeline(u64 start, int row1, int row2, const char *backtrace);
-extern void svg_partial_wakeline(u64 start, int row1, char *desc1, int row2, char *desc2, const char *backtrace);
-extern void svg_interrupt(u64 start, int row, const char *backtrace);
-extern void svg_text(int Yslot, u64 start, const char *text);
-extern void svg_close(void);
-extern int svg_build_topology_map(char *sib_core, int sib_core_nr,
-				  char *sib_thr, int sib_thr_nr);
+void svg_time_grid(double min_thickness);
+void svg_io_legenda(void);
+void svg_legenda(void);
+void svg_wakeline(u64 start, int row1, int row2, const char *backtrace);
+void svg_partial_wakeline(u64 start, int row1, char *desc1, int row2, char *desc2, const char *backtrace);
+void svg_interrupt(u64 start, int row, const char *backtrace);
+void svg_text(int Yslot, u64 start, const char *text);
+void svg_close(void);
+int svg_build_topology_map(char *sib_core, int sib_core_nr, char *sib_thr, int sib_thr_nr);
 
 extern int svg_page_width;
 extern u64 svg_highlight;
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index a937053a0ae0..c8b7544d9267 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -34,8 +34,8 @@
 #endif
 
 #ifdef HAVE_LIBELF_SUPPORT
-extern Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
-				GElf_Shdr *shp, const char *name, size_t *idx);
+Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
+			     GElf_Shdr *shp, const char *name, size_t *idx);
 #endif
 
 #ifndef DMGL_PARAMS
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 2080142d7244..46d4dd013a8b 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -133,17 +133,17 @@ extern char buildid_dir[];
 #define PERF_GTK_DSO  "libperf-gtk.so"
 
 /* General helper functions */
-extern void usage(const char *err) NORETURN;
-extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
-extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
-extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
+void usage(const char *err) NORETURN;
+void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
+int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
+void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
 
 #include "../../../include/linux/stringify.h"
 
-extern void set_warning_routine(void (*routine)(const char *err, va_list params));
+void set_warning_routine(void (*routine)(const char *err, va_list params));
 
-extern int prefixcmp(const char *str, const char *prefix);
-extern void set_buildid_dir(const char *dir);
+int prefixcmp(const char *str, const char *prefix);
+void set_buildid_dir(const char *dir);
 
 #ifdef __GLIBC_PREREQ
 #if __GLIBC_PREREQ(2, 1)
@@ -164,8 +164,8 @@ static inline char *gitstrchrnul(const char *s, int c)
 /*
  * Wrappers:
  */
-extern char *xstrdup(const char *str);
-extern void *xrealloc(void *ptr, size_t size) __attribute__((weak));
+char *xstrdup(const char *str);
+void *xrealloc(void *ptr, size_t size) __attribute__((weak));
 
 
 static inline void *zalloc(size_t size)