[PATCH bpf-next v3 0/2] bpftool: Batch bounded hash map dumps

[Tianyi Chen <diannaaav@gmail.com>]

Use lookup batches for ordinary hash maps whose maximum key/value
storage fits within 4 MiB. The second patch checks complete output around
the batch boundary, short keys, odd-sized values and BTF formatting.

Changes in v3:
- Explain the batching benefit, conservative memory bound, and why
  ineligible maps retain the existing traversal in the commit message.
- Rebase onto current bpf-next and use Assisted-by: LLM.

The v2 implementation and tests are unchanged. Fatal batch diagnostics
remain on stderr so JSON element arrays contain only map entries.

v2: https://lore.kernel.org/r/178874362960.1415955.9584865244247659247.batch-v2-0@tychen.cc
Request: https://github.com/libbpf/bpftool/issues/63

The previous version's CI PR expired after repeated "Patch is empty"
reports. The revised series applies cleanly to the current tree and is
sent as a new thread using git format-patch and git send-email.

Validation:
- Built bpftool and its manual pages, and built the focused selftest
  runner with LLVM 20.
- All 11 bpftool_map_batch subtests passed with no skips or failures
  in an x86-64 KVM guest running Linux 7.3.0-rc2 from current bpf/master.
- The four bpftool series were tested together: all 69 subtests passed.
  The cpumask suite (36 subtests) and test_maps also passed with no skips.
- Bash syntax and the existing bpftool synchronization checks passed.

This was a focused run; unrelated selftests requiring unavailable kernel
features were excluded from the build with PERMISSIVE=1.

Tianyi Chen (2):
  bpftool: Use batch lookups for bounded hash map dumps
  selftests/bpf: Check bpftool batch map dump contents

 tools/bpf/bpftool/map.c                       | 116 ++++++++++-
 .../bpf/prog_tests/bpftool_map_batch.c        | 187 ++++++++++++++++++
 2 files changed, 295 insertions(+), 8 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/bpftool_map_batch.c


base-commit: af0b84a9215d951d16f26b7ee34353b970cf5d4e
-- 
2.55.0