NOTE
Linux Performance Tuning
An evidence-driven workflow across CPU, memory, disk, network, kernel, and application layers.
This is a historical learning note and may contain outdated or incomplete understanding.
Performance tuning is a measurement loop: define the user-visible symptom and target, identify the saturated or delayed resource, find the responsible workload, change one relevant factor, and remeasure.
Check CPU/run queues, memory/reclaim, disk latency/queueing, network loss/retransmission, locks, syscalls, and application profiles. Tail latency and error rate matter as much as averages.
Avoid “recommended sysctl” lists without a bottleneck. Kernel defaults are designed for broad workloads, and a setting that helps one traffic pattern can harm another.