[PATCH bpf-next 0/3] improve and fix barriers for walking perf rb

[Daniel Borkmann <daniel@iogearbox.net>]

This set first adds smp_* barrier variants to tools infrastructure
and in a second step updates perf and libbpf to make use of them.
For details, please see individual patches, thanks!

Arnaldo, if there are no objections, could this be routed via bpf-next
with Acked-by's due to later dependencies in libbpf? Alternatively,
I could also get the 2nd patch out during merge window, but perhaps
it's okay to do in one go as there shouldn't be much conflict in perf.

Thanks!

Daniel Borkmann (3):
  tools: add smp_* barrier variants to include infrastructure
  tools, perf: use smp_{rmb,mb} barriers instead of {rmb,mb}
  bpf, libbpf: use proper barriers in perf ring buffer walk

 tools/arch/arm64/include/asm/barrier.h | 10 ++++++++++
 tools/arch/x86/include/asm/barrier.h   |  9 ++++++---
 tools/include/asm/barrier.h            | 11 +++++++++++
 tools/lib/bpf/libbpf.c                 | 25 +++++++++++++++++++------
 tools/perf/util/mmap.h                 |  5 +++--
 5 files changed, 49 insertions(+), 11 deletions(-)

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2.9.5