Cache cpuidle names (was re-reading name sysfs every tick × cores)
Cache CPU sysfs dir list + register cpufreq/throttle once
Map for per-core prev lookups (was O(n²) .find)
Dedupe meminfo/vmstat once per tick
Cache iface speed/duplex/mtu/qlen (30s)
Cache inotify limits (30s)
Gate registerChart for IRQs, cpuidle, peardock mapped charts
Remove leftover profile() stderr timers
Cache os.cpus().length in docker collector
Grow fd-cache buffer past 64KB for /proc/interrupts etc.