192cf32243
selftests/seccomp: Compare bitmap vs filter overhead
...
As part of the seccomp benchmarking, include the expectations with
regard to the timing behavior of the constant action bitmaps, and report
inconsistencies better.
Example output with constant action bitmaps on x86:
$ sudo ./seccomp_benchmark 100000000
Current BPF sysctl settings:
net.core.bpf_jit_enable = 1
net.core.bpf_jit_harden = 0
Benchmarking 200000000 syscalls...
129.359381409 - 0.008724424 = 129350656985 (129.4s)
getpid native: 646 ns
264.385890006 - 129.360453229 = 135025436777 (135.0s)
getpid RET_ALLOW 1 filter (bitmap): 675 ns
399.400511893 - 264.387045901 = 135013465992 (135.0s)
getpid RET_ALLOW 2 filters (bitmap): 675 ns
545.872866260 - 399.401718327 = 146471147933 (146.5s)
getpid RET_ALLOW 3 filters (full): 732 ns
696.337101319 - 545.874097681 = 150463003638 (150.5s)
getpid RET_ALLOW 4 filters (full): 752 ns
Estimated total seccomp overhead for 1 bitmapped filter: 29 ns
Estimated total seccomp overhead for 2 bitmapped filters: 29 ns
Estimated total seccomp overhead for 3 full filters: 86 ns
Estimated total seccomp overhead for 4 full filters: 106 ns
Estimated seccomp entry overhead: 29 ns
Estimated seccomp per-filter overhead (last 2 diff): 20 ns
Estimated seccomp per-filter overhead (filters / 4): 19 ns
Expectations:
native ≤ 1 bitmap (646 ≤ 675): ✔️
native ≤ 1 filter (646 ≤ 732): ✔️
per-filter (last 2 diff) ≈ per-filter (filters / 4) (20 ≈ 19): ✔️
1 bitmapped ≈ 2 bitmapped (29 ≈ 29): ✔️
entry ≈ 1 bitmapped (29 ≈ 29): ✔️
entry ≈ 2 bitmapped (29 ≈ 29): ✔️
native + entry + (per filter * 4) ≈ 4 filters total (755 ≈ 752): ✔️
[YiFei: Changed commit message to show stats for this patch series]
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/1b61df3db85c5f7f1b9202722c45e7b39df73ef2.1602431034.git.yifeifz2@illinois.edu
2020-11-20 11:16:34 -08:00
81a0c8bc82
selftests/seccomp: Improve calibration loop
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The seccomp benchmark calibration loop did not need to take so long.
Instead, use a simple 1 second timeout and multiply up to target. It
does not need to be accurate.
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-10 16:01:52 -07:00
d3a37ea9f6
selftests/seccomp: Expand benchmark to per-filter measurements
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It's useful to see how much (at a minimum) each filter adds to the
syscall overhead. Add additional calculations.
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-10 16:01:52 -07:00
967d7ba841
selftests/seccomp: Add simple seccomp overhead benchmark
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This attempts to produce a comparison between native getpid() and a
RET_ALLOW-filtered getpid(), to measure the overhead cost of using
seccomp().
Signed-off-by: Kees Cook <keescook@chromium.org>
2017-08-14 13:46:41 -07:00
Kees Cook