Messages in this thread | | | From | Jiri Olsa <> | Subject | [PATCHv2 bpf-next 0/4] bpf: Speed up symbol resolving in kprobe multi link | Date | Mon, 18 Apr 2022 14:48:30 +0200 |
| |
hi, sending additional fix for symbol resolving in kprobe multi link requested by Alexei and Andrii [1].
This speeds up bpftrace kprobe attachment, when using pure symbols (3344 symbols) to attach:
Before:
# perf stat -r 5 -e cycles ./src/bpftrace -e 'kprobe:x* { } i:ms:1 { exit(); }' ... 6.5681 +- 0.0225 seconds time elapsed ( +- 0.34% )
After:
# perf stat -r 5 -e cycles ./src/bpftrace -e 'kprobe:x* { } i:ms:1 { exit(); }' ... 0.5661 +- 0.0275 seconds time elapsed ( +- 4.85% )
v2 changes (first version [2]): - removed the 2 seconds check [Alexei] - moving/forcing symbols sorting out of kallsyms_lookup_names function [Alexei] - skipping one array allocation and copy_from_user [Andrii] - several small fixes [Masami,Andrii] - build fix [kernel test robot]
thanks, jirka
[1] https://lore.kernel.org/bpf/CAEf4BzZtQaiUxQ-sm_hH2qKPRaqGHyOfEsW96DxtBHRaKLoL3Q@mail.gmail.com/ [2] https://lore.kernel.org/bpf/20220407125224.310255-1-jolsa@kernel.org/ --- Jiri Olsa (4): kallsyms: Add kallsyms_lookup_names function fprobe: Resolve symbols with kallsyms_lookup_names bpf: Resolve symbols with kallsyms_lookup_names for kprobe multi link selftests/bpf: Add attach bench test
include/linux/kallsyms.h | 6 ++++++ kernel/kallsyms.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- kernel/trace/bpf_trace.c | 113 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------------------------------------- kernel/trace/fprobe.c | 32 ++++++++++++-------------------- tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c | 136 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ tools/testing/selftests/bpf/progs/kprobe_multi_empty.c | 12 ++++++++++++ 6 files changed, 302 insertions(+), 67 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/kprobe_multi_empty.c
| |