23 assertions over 8 cases covering both tweak_vm_sysctl and
tweak_network_sysctl: the skip path, the write-when-the-drop-in-is-
missing path that a naive "nothing to do" check gets wrong, the
value-differs path, an unreadable-sysctl path, and the tcp_bbr guard.
arch_desktop_harness.sh is the third family harness, supplying the
globals and apply_tweak that live in optimize_arch_desktop.sh rather
than in any lib. arch_cpu.sh and arch_hardware.sh will reuse it.
SYSCTL_DROPIN_DIR defaults to the real /etc/sysctl.d, matching the
seam ubuntu_perf_more.sh and arch_perf_fixes.sh already carry; the
suite runs un-jailed in ci_mirror.sh and CI, so a bind mount would
protect nothing. Both real drop-ins keep their Mar 2 mtimes.
_t_run lands in lib_test_core.sh because `out="$(func)"` forks a
subshell and kcov never registers a lib whose first execution happens
inside one -- measured as 0 lines via $( ) against 54 lines via a
direct call.
arch_sysctl.sh STAYS on the coverage allowlist: it still reports "kcov
instrumented no lines" through the jail, while ubuntu_perf_more.sh
measures 32/32 in the same worktree and the same invocation. The tests
are real and green; the coverage number is not yet obtainable, and the
exemption may only come off once it is.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
