libbpf

2,477 Commits 29 Branches 44 Tags

2 Commits

Author	SHA1	Message	Date
Jackie Liu	b9c4ad5468	libbpf: Use available_filter_functions_addrs with multi-kprobes Now that kernel provides a new available_filter_functions_addrs file which can help us avoid the need to cross-validate available_filter_functions and kallsyms, we can improve efficiency of multi-attach kprobes. For example, on my device, the sample program [1] of start time: $ sudo ./funccount "tcp_*" before after 1.2s 1.0s [1]: https://github.com/JackieLiu1/ketones/tree/master/src/funccount Signed-off-by: Jackie Liu <liuyun01@kylinos.cn> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230705091209.3803873-2-liu.yun@linux.dev	2023-07-07 18:55:44 -07:00
Jackie Liu	732c4c6df2	libbpf: Cross-join available_filter_functions and kallsyms for multi-kprobes When using regular expression matching with "kprobe multi", it scans all the functions under "/proc/kallsyms" that can be matched. However, not all of them can be traced by kprobe.multi. If any one of the functions fails to be traced, it will result in the failure of all functions. The best approach is to filter out the functions that cannot be traced to ensure proper tracking of the functions. Closes: https://lore.kernel.org/oe-kbuild-all/202307030355.TdXOHklM-lkp@intel.com/ Reported-by: kernel test robot <lkp@intel.com> Suggested-by: Jiri Olsa <jolsa@kernel.org> Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com> Signed-off-by: Jackie Liu <liuyun01@kylinos.cn> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230705091209.3803873-1-liu.yun@linux.dev	2023-07-07 18:55:44 -07:00

Author

SHA1

Message

Date

Jackie Liu

b9c4ad5468

libbpf: Use available_filter_functions_addrs with multi-kprobes

Now that kernel provides a new available_filter_functions_addrs file
which can help us avoid the need to cross-validate
available_filter_functions and kallsyms, we can improve efficiency of
multi-attach kprobes. For example, on my device, the sample program [1]
of start time:

$ sudo ./funccount "tcp_*"

before   after
1.2s     1.0s

  [1]: https://github.com/JackieLiu1/ketones/tree/master/src/funccount

Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230705091209.3803873-2-liu.yun@linux.dev

2023-07-07 18:55:44 -07:00

Jackie Liu

732c4c6df2

libbpf: Cross-join available_filter_functions and kallsyms for multi-kprobes

When using regular expression matching with "kprobe multi", it scans all
the functions under "/proc/kallsyms" that can be matched. However, not all
of them can be traced by kprobe.multi. If any one of the functions fails
to be traced, it will result in the failure of all functions. The best
approach is to filter out the functions that cannot be traced to ensure
proper tracking of the functions.

Closes: https://lore.kernel.org/oe-kbuild-all/202307030355.TdXOHklM-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Jiri Olsa <jolsa@kernel.org>
Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230705091209.3803873-1-liu.yun@linux.dev

2023-07-07 18:55:44 -07:00