CHECK: extern prototypes should be avoided in .h files
#42: FILE: include/linux/perf_event.h:1723:
+extern void __init_perf_callchain_ctx(struct perf_callchain_entry_ctx *ctx,

WARNING: line length of 100 exceeds 80 columns
#46: FILE: include/linux/perf_event.h:1727:
+extern void __get_perf_callchain_kernel(struct perf_callchain_entry_ctx *ctx, struct pt_regs *regs);

CHECK: extern prototypes should be avoided in .h files
#46: FILE: include/linux/perf_event.h:1727:
+extern void __get_perf_callchain_kernel(struct perf_callchain_entry_ctx *ctx, struct pt_regs *regs);

WARNING: line length of 98 exceeds 80 columns
#47: FILE: include/linux/perf_event.h:1728:
+extern void __get_perf_callchain_user(struct perf_callchain_entry_ctx *ctx, struct pt_regs *regs);

CHECK: extern prototypes should be avoided in .h files
#47: FILE: include/linux/perf_event.h:1728:
+extern void __get_perf_callchain_user(struct perf_callchain_entry_ctx *ctx, struct pt_regs *regs);

CHECK: multiple assignments should be avoided
#67: FILE: kernel/events/callchain.c:226:
+	ctx->nr			= entry->nr = 0;

WARNING: line length of 92 exceeds 80 columns
#73: FILE: kernel/events/callchain.c:232:
+void __get_perf_callchain_kernel(struct perf_callchain_entry_ctx *ctx, struct pt_regs *regs)

WARNING: line length of 90 exceeds 80 columns
#83: FILE: kernel/events/callchain.c:242:
+void __get_perf_callchain_user(struct perf_callchain_entry_ctx *ctx, struct pt_regs *regs)

total: 0 errors, 4 warnings, 4 checks, 115 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 3a3acef666ab ("perf: Refactor get_perf_callchain") 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, 4 warnings, 4 checks, 115 lines checked