From ba3653f6e500f32385f766e308264357631db8b5 Mon Sep 17 00:00:00 2001 From: Vito Caputo Date: Sun, 19 Jan 2025 15:16:02 -0800 Subject: vmon: introduce -R/--reaper flag Beginnings of PR_SET_CHILD_SUBREAPER mode, this only adds the CLI flags. Becoming a subreaper is only relevant to running commands via vmon. If the commands being executed fork/exec/daemonize or otherwise may produce orphaned processes, they escape the scoped hierarchical monitoring when init inherits them, so you lose visibility into their actions once orphaned. By becoming a subreaper, vmon can be the process inheriting those orphans, so they may continue being monitored, as if vmon were init, for its descendants. --- src/vmon.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'src') diff --git a/src/vmon.c b/src/vmon.c index e49b360..059bcd5 100644 --- a/src/vmon.c +++ b/src/vmon.c @@ -49,6 +49,7 @@ typedef struct vmon_t { int linger; int dump_procs; int mem_locked; + int reaper; time_t start_time; int snapshots_interval; int snapshot; @@ -205,6 +206,7 @@ static void print_help(void) " -v --version Print version\n" " -D --dump-procs Dump libvmon internal processes table (debugging aid)\n" " -L --mem-locked Lock in memory using mlockall(MCL_CURRENT|MCL_FUTURE)\n" + " -R --reaper Become the child subreaper (see prctl(2); PR_SET_CHILD_SUBREAPER)\n" " -W --width Chart width\n" " -z --hertz Sample rate in hertz\n" "-------------------------------------------------------------------------------" @@ -498,6 +500,9 @@ static int vmon_handle_argv(vmon_t *vmon, int argc, const char * const *argv) } else if (is_flag(*argv, "-L", "--mem-locked")) { vmon->mem_locked = 1; last = argv; + } else if (is_flag(*argv, "-R", "--reaper")) { + vmon->reaper = 1; + last = argv; } else if ((*argv)[0] == '-') { VWM_ERROR("Unrecognized argument: \"%s\", try --help\n", argv[0]); exit(EXIT_FAILURE); -- cgit v1.2.3