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	Commit message (Collapse)	Author	Age	Files	Lines
*	selftests/seccomp: Compare bitmap vs filter overhead	Kees Cook	2020-11-20	1	-1/+1
\| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \|	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
*	selftests/seccomp: use 90s as timeout	Thadeu Lima de Souza Cascardo	2020-07-11	1	-0/+1
	As seccomp_benchmark tries to calibrate how many samples will take more than 5 seconds to execute, it may end up picking up a number of samples that take 10 (but up to 12) seconds. As the calibration will take double that time, it takes around 20 seconds. Then, it executes the whole thing again, and then once more, with some added overhead. So, the thing might take more than 40 seconds, which is too close to the 45s timeout. That is very dependent on the system where it's executed, so may not be observed always, but it has been observed on x86 VMs. Using a 90s timeout seems safe enough. Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Link: https://lore.kernel.org/r/20200601123202.1183526-1-cascardo@canonical.com Signed-off-by: Kees Cook <keescook@chromium.org>