CHECK: extern prototypes should be avoided in .h files
#37: FILE: include/linux/perf_event.h:1727:
+extern struct perf_callchain_entry *get_callchain_entry(void);

CHECK: extern prototypes should be avoided in .h files
#38: FILE: include/linux/perf_event.h:1728:
+extern void put_callchain_entry(struct perf_callchain_entry *entry);

total: 0 errors, 0 warnings, 2 checks, 102 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

Commit 4ccda54f70c4 ("perf: Add rctx in perf_callchain_entry") has style problems, please review.

NOTE: Ignored message types: ALLOC_SIZEOF_STRUCT BAD_REPORTED_BY_LINK CAMELCASE COMMIT_LOG_LONG_LINE FILE_PATH_CHANGES GIT_COMMIT_ID MACRO_ARG_REUSE NO_AUTHOR_SIGN_OFF

NOTE: If any of the errors are false positives, please report
      them to the maintainer, see CHECKPATCH in MAINTAINERS.
total: 0 errors, 0 warnings, 2 checks, 102 lines checked