Perf's expr code currently builds an array of strings then removes duplicates. The array is larger than necessary and has recently been increased in size. When this was done it was commented that a hashmap would be preferable.
libbpf has a hashmap but libbpf isn't currently required to build perf. To satisfy various concerns this change copies libbpf's hashmap into libapi, it then adds a check in perf that the two are in sync. Andrii's patch to hashmap from bpf-next is brought into this set to fix issues with hashmap__clear. Three minor changes to libbpf's hashmap are made that remove an unused dependency, fix a compiler warning and make sure the hashmap isn't part of the symbols in a static build of libbpf (dsos are handled by the existing version script). Two perf test are also brought in as they need refactoring to account for the expr API change and it is expected they will land aheadof this. https://lore.kernel.org/lkml/20200513062236.854-2-irog...@google.com/ Tested with 'perf test' and make -C tools/perf build-test. The hashmap change was originally part of an RFC: https://lore.kernel.org/lkml/20200508053629.210324-1-irog...@google.com/ Andrii Nakryiko (1): libbpf: Fix memory leak and possible double-free in hashmap__clear Ian Rogers (7): libbpf hashmap: Remove unused #include libbpf hashmap: Fix signedness warnings libbpf hashmap: Localize static hashmap__* symbols tools lib/api: Copy libbpf hashmap to libapi perf test: Provide a subtest callback to ask for the reason for skipping a subtest perf test: Improve pmu event metric testing perf expr: Migrate expr ids table to a hashmap tools/lib/api/Build | 1 + tools/lib/api/hashmap.c | 238 ++++++++++++++++++++++++++++++++ tools/lib/api/hashmap.h | 177 ++++++++++++++++++++++++ tools/lib/bpf/Makefile | 2 + tools/lib/bpf/hashmap.c | 10 +- tools/lib/bpf/hashmap.h | 1 - tools/perf/check-headers.sh | 4 + tools/perf/tests/builtin-test.c | 18 ++- tools/perf/tests/expr.c | 40 +++--- tools/perf/tests/pmu-events.c | 169 ++++++++++++++++++++++- tools/perf/tests/tests.h | 4 + tools/perf/util/expr.c | 129 +++++++++-------- tools/perf/util/expr.h | 22 ++- tools/perf/util/expr.y | 22 +-- tools/perf/util/metricgroup.c | 87 ++++++------ tools/perf/util/stat-shadow.c | 49 ++++--- 16 files changed, 793 insertions(+), 180 deletions(-) create mode 100644 tools/lib/api/hashmap.c create mode 100644 tools/lib/api/hashmap.h -- 2.26.2.761.g0e0b3e54be-goog
