Hello, I found that call stack from the lock tracepoint (using bpf_get_stackid) can be different on each configuration. For example it's very different when I run it on a VM than on a real machine. The perf lock contention relies on the stack trace to get the lock caller names, this kind of difference can be annoying. Ideally we could skip stack trace entries for internal BPF or lock functions and get the correct caller, but it's not the case as of today. Currently it's hard coded to control the behavior of stack traces for the lock contention tracepoints. To handle those differences, add two new options to control the number of stack entries and how many it skips. The default value worked well on my VM setup, but I had to use --stack-skip=5 on real machines. You can get it from 'perf/lock-stack-v1' branch in git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git Thanks, Namhyung Namhyung Kim (4): perf lock contention: Factor out get_symbol_name_offset() perf lock contention: Show full callstack with -v option perf lock contention: Allow to change stack depth and skip perf lock contention: Skip stack trace from BPF tools/perf/Documentation/perf-lock.txt | 6 ++ tools/perf/builtin-lock.c | 89 ++++++++++++++----- tools/perf/util/bpf_lock_contention.c | 21 +++-- .../perf/util/bpf_skel/lock_contention.bpf.c | 3 +- tools/perf/util/lock-contention.h | 3 + 5 files changed, 96 insertions(+), 26 deletions(-) base-commit: 6c3bd8d3e01d9014312caa52e4ef1c29d5249648 -- 2.37.2.789.g6183377224-goog
