[PATCH -next v3 0/2] perf stat: Support inherit events for bperf

Tengda Wu
2024-09-16T01:53:49Z

Hi,

Here is the 3th version of the series to support inherit events for bperf.
This version add pid or tgid selection based on filter type in new_task
prog to avoid memory waste and potential count loss.

bperf (perf-stat --bpf-counter) has not supported inherit events
during fork() since it was first introduced.

This patch series tries to add this support by:
1) adding two new bpf programs to monitor task lifecycle;
2) recording new tasks in the filter map dynamically;
3) reusing `accum_key` of parent task for new tasks.

Thanks,
Tengda

Changelog:
---------
v3: (Address comments from Namhyung, thanks)
* Use pid or tgid based on filter type in new_task prog
* Add comments to explain pid usage for TGID type in exit_task prog

v2: https://lore.kernel.org/all/20240905115918.772234-1-wutengda@huaweicloud.com/
* Remove the unused init_filter_entries in follower bpf, declare
a global filter_entry_count in bpf_counter instead
* Attach on_newtask and on_exittask progs only if the filter type
is either PID or TGID

v1: https://lore.kernel.org/all/20240904123103.732507-1-wutengda@huaweicloud.com/

Tengda Wu (2):
perf stat: Support inherit events during fork() for bperf
perf test: Use sqrtloop workload to test bperf event

tools/perf/tests/shell/stat_bpf_counters.sh | 2 +-
tools/perf/util/bpf_counter.c | 32 +++++--
tools/perf/util/bpf_skel/bperf_follower.bpf.c | 87 +++++++++++++++++--
tools/perf/util/bpf_skel/bperf_u.h | 5 ++
4 files changed, 112 insertions(+), 14 deletions(-)

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2.34.1