主题： perf

• Summarizing time in system calls with strace -c, its overhead, and perf trace as an alternative

  strace -c counts time, calls and errors per system call instead of printing every call, but strace's own manual warns that a traced process runs more slowly than an untraced one; perf trace, described as a strace-inspired tool built on perf_events rather than ptrace, is the lower-ceremony alternative when that overhead matters.

  methodology · en · reviewed · 知识截至 2026-09-24

• CPU profiling with perf: perf top, perf record -g, perf report, and perf_event_paranoid

  perf top gives an immediate live profile; perf record -g saves a call-graph profile to disk for perf report to read later. The kernel's perf_event_paranoid setting controls what an unprivileged user can do, and symbol resolution needs matching debug information for every frame in the stack.

  methodology · en · reviewed · 知识截至 2026-09-24

机器可读： JSON