Calculate average process lifetime and turnover rate from start and end timestamps.
Dividing system uptime by the cumulative fork count since boot (/proc/stat's 'processes' field) gives a coarse average process lifetime — a genuinely rough approximation, since it implicitly treats every forked process as having exited by now and doesn't account for the current live processes (some of which, like long-running daemons, dramatically skew a true average upward). It's most useful as a relative signal: a very small average (well under a second) indicates a workload dominated by many short-lived process invocations, common in shell-scripting-heavy automation or per-request-fork architectures, versus a workload dominated by a handful of long-running services with comparatively few forks over the same uptime.
Average process lifetime (coarse approximation)
avg_lifetime = uptime_seconds / total_forks_since_boot
It assumes every process forked since boot has already exited, dividing all elapsed uptime evenly across all forks — but currently-running long-lived processes (like persistent daemons that started at boot and haven't exited) are counted the same as one-shot scripts that ran for milliseconds, which skews a true 'typical lifetime' figure. It's a useful churn indicator, not a precise per-process lifetime distribution.
Heavy use of shell pipelines and utilities (each `grep`, `awk`, `sed` invocation is its own short-lived process), cron jobs firing frequently, CI/build systems spawning many compiler/tool invocations, or legacy CGI-style web architectures that fork a fresh process per HTTP request all drive average lifetime down significantly.
Not inherently — it's simply descriptive of the workload's process model. It becomes a performance concern only if fork/exec overhead itself (not the useful work being done) becomes a measurable fraction of total resource usage, which is worth checking with `perf stat` or similar profiling before concluding it needs architectural change (e.g. moving to a long-lived worker-pool model).