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  1. 03 12月, 2021 4 次提交
  3. 01 12月, 2021 3 次提交
    • J
      selftest/bpf/benchs: Add bpf_loop benchmark · ec151037
      由 Joanne Koong 提交于 
      Add benchmark to measure the throughput and latency of the bpf_loop
call.

Testing this on my dev machine on 1 thread, the data is as follows:

        nr_loops: 10
bpf_loop - throughput: 198.519 ± 0.155 M ops/s, latency: 5.037 ns/op

        nr_loops: 100
bpf_loop - throughput: 247.448 ± 0.305 M ops/s, latency: 4.041 ns/op

        nr_loops: 500
bpf_loop - throughput: 260.839 ± 0.380 M ops/s, latency: 3.834 ns/op

        nr_loops: 1000
bpf_loop - throughput: 262.806 ± 0.629 M ops/s, latency: 3.805 ns/op

        nr_loops: 5000
bpf_loop - throughput: 264.211 ± 1.508 M ops/s, latency: 3.785 ns/op

        nr_loops: 10000
bpf_loop - throughput: 265.366 ± 3.054 M ops/s, latency: 3.768 ns/op

        nr_loops: 50000
bpf_loop - throughput: 235.986 ± 20.205 M ops/s, latency: 4.238 ns/op

        nr_loops: 100000
bpf_loop - throughput: 264.482 ± 0.279 M ops/s, latency: 3.781 ns/op

        nr_loops: 500000
bpf_loop - throughput: 309.773 ± 87.713 M ops/s, latency: 3.228 ns/op

        nr_loops: 1000000
bpf_loop - throughput: 262.818 ± 4.143 M ops/s, latency: 3.805 ns/op

>From this data, we can see that the latency per loop decreases as the
number of loops increases. On this particular machine, each loop had an
overhead of about ~4 ns, and we were able to run ~250 million loops
per second.
Signed-off-by: NJoanne Koong <joannekoong@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211130030622.4131246-5-joannekoong@fb.com
      ec151037
    • J
      selftests/bpf: Measure bpf_loop verifier performance · f6e659b7
      由 Joanne Koong 提交于 
      This patch tests bpf_loop in pyperf and strobemeta, and measures the
verifier performance of replacing the traditional for loop
with bpf_loop.

The results are as follows:

~strobemeta~

Baseline
    verification time 6808200 usec
    stack depth 496
    processed 554252 insns (limit 1000000) max_states_per_insn 16
    total_states 15878 peak_states 13489  mark_read 3110
    #192 verif_scale_strobemeta:OK (unrolled loop)

Using bpf_loop
    verification time 31589 usec
    stack depth 96+400
    processed 1513 insns (limit 1000000) max_states_per_insn 2
    total_states 106 peak_states 106 mark_read 60
    #193 verif_scale_strobemeta_bpf_loop:OK

~pyperf600~

Baseline
    verification time 29702486 usec
    stack depth 368
    processed 626838 insns (limit 1000000) max_states_per_insn 7
    total_states 30368 peak_states 30279 mark_read 748
    #182 verif_scale_pyperf600:OK (unrolled loop)

Using bpf_loop
    verification time 148488 usec
    stack depth 320+40
    processed 10518 insns (limit 1000000) max_states_per_insn 10
    total_states 705 peak_states 517 mark_read 38
    #183 verif_scale_pyperf600_bpf_loop:OK

Using the bpf_loop helper led to approximately a 99% decrease
in the verification time and in the number of instructions.
Signed-off-by: NJoanne Koong <joannekoong@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211130030622.4131246-4-joannekoong@fb.com
      f6e659b7
    • J
      selftests/bpf: Add bpf_loop test · 4e5070b6
      由 Joanne Koong 提交于 
      Add test for bpf_loop testing a variety of cases:
various nr_loops, null callback ctx, invalid flags, nested callbacks.
Signed-off-by: NJoanne Koong <joannekoong@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211130030622.4131246-3-joannekoong@fb.com
      4e5070b6
  5. 29 11月, 2021 1 次提交
  7. 26 11月, 2021 9 次提交
  9. 23 11月, 2021 1 次提交
  11. 20 11月, 2021 1 次提交
  13. 19 11月, 2021 2 次提交
  15. 18 11月, 2021 1 次提交
  17. 17 11月, 2021 3 次提交
  19. 16 11月, 2021 4 次提交
    • A
      selftests/bpf: Add uprobe triggering overhead benchmarks · d41bc48b
      由 Andrii Nakryiko 提交于 
      Add benchmark to measure overhead of uprobes and uretprobes. Also have
a baseline (no uprobe attached) benchmark.

On my dev machine, baseline benchmark can trigger 130M user_target()
invocations. When uprobe is attached, this falls to just 700K. With
uretprobe, we get down to 520K:

  $ sudo ./bench trig-uprobe-base -a
  Summary: hits  131.289 ± 2.872M/s

  # UPROBE
  $ sudo ./bench -a trig-uprobe-without-nop
  Summary: hits    0.729 ± 0.007M/s

  $ sudo ./bench -a trig-uprobe-with-nop
  Summary: hits    1.798 ± 0.017M/s

  # URETPROBE
  $ sudo ./bench -a trig-uretprobe-without-nop
  Summary: hits    0.508 ± 0.012M/s

  $ sudo ./bench -a trig-uretprobe-with-nop
  Summary: hits    0.883 ± 0.008M/s

So there is almost 2.5x performance difference between probing nop vs
non-nop instruction for entry uprobe. And 1.7x difference for uretprobe.

This means that non-nop uprobe overhead is around 1.4 microseconds for uprobe
and 2 microseconds for non-nop uretprobe.

For nop variants, uprobe and uretprobe overhead is down to 0.556 and
1.13 microseconds, respectively.

For comparison, just doing a very low-overhead syscall (with no BPF
programs attached anywhere) gives:

  $ sudo ./bench trig-base -a
  Summary: hits    4.830 ± 0.036M/s

So uprobes are about 2.67x slower than pure context switch.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211116013041.4072571-1-andrii@kernel.org
      d41bc48b
    • Q
      selftests/bpf: Configure dir paths via env in test_bpftool_synctypes.py · e12cd158
      由 Quentin Monnet 提交于 
      Script test_bpftool_synctypes.py parses a number of files in the bpftool
directory (or even elsewhere in the repo) to make sure that the list of
types or options in those different files are consistent. Instead of
having fixed paths, let's make the directories configurable through
environment variable. This should make easier in the future to run the
script in a different setup, for example on an out-of-tree bpftool
mirror with a different layout.
Signed-off-by: NQuentin Monnet <quentin@isovalent.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211115225844.33943-4-quentin@isovalent.com
      e12cd158
    • Q
      bpftool: Update doc (use susbtitutions) and test_bpftool_synctypes.py · b6231815
      由 Quentin Monnet 提交于 
      test_bpftool_synctypes.py helps detecting inconsistencies in bpftool
between the different list of types and options scattered in the
sources, the documentation, and the bash completion. For options that
apply to all bpftool commands, the script had a hardcoded list of
values, and would use them to check whether the man pages are
up-to-date. When writing the script, it felt acceptable to have this
list in order to avoid to open and parse bpftool's main.h every time,
and because the list of global options in bpftool doesn't change so
often.

However, this is prone to omissions, and we recently added a new
-l|--legacy option which was described in common_options.rst, but not
listed in the options summary of each manual page. The script did not
complain, because it keeps comparing the hardcoded list to the (now)
outdated list in the header file.

To address the issue, this commit brings the following changes:

- Options that are common to all bpftool commands (--json, --pretty, and
  --debug) are moved to a dedicated file, and used in the definition of
  a RST substitution. This substitution is used in the sources of all
  the man pages.

- This list of common options is updated, with the addition of the new
  -l|--legacy option.

- The script test_bpftool_synctypes.py is updated to compare:
    - Options specific to a command, found in C files, for the
      interactive help messages, with the same specific options from the
      relevant man page for that command.
    - Common options, checked just once: the list in main.h is
      compared with the new list in substitutions.rst.
Signed-off-by: NQuentin Monnet <quentin@isovalent.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211115225844.33943-3-quentin@isovalent.com
      b6231815
    • Y
      selftests/bpf: Add a dedup selftest with equivalent structure types · 47461583
      由 Yonghong Song 提交于 
      Without previous libbpf patch, the following error will occur:

  $ ./test_progs -t btf
  ...
  do_test_dedup:FAIL:check btf_dedup failed errno:-22#13/205 btf/dedup: btf_type_tag #5, struct:FAIL

And the previous libbpf patch fixed the issue.
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211115163943.3922547-1-yhs@fb.com
      47461583
  21. 13 11月, 2021 2 次提交
  23. 12 11月, 2021 9 次提交