sys/kern/kern_heartbeat.c

30  * heartbeat(9) -- periodic checks to ensure CPUs are making progress
46  *	sysctl -w kern.heartbeat.max_period=5
48  *	sysctl -w kern.heartbeat.max_period=0
50  *	sysctl -w kern.heartbeat.max_period=5
92 #include "heartbeat.h"
100 #include <sys/heartbeat.h>
117  *	can avoid multiplication or division in the heartbeat routine.
131  *	Suspend heartbeat monitoring of the current CPU.
156  *	Resume heartbeat monitoring of ci.
158  *	Called at startup while cold, and whenever heartbeat monitoring
180  *	Resume heartbeat monitoring of the current CPU.
200 	 * attack as soon as the heartbeat checks resume.
213  *	True if timecounter heartbeat checks are suspended because the
214  *	timecounter may not be advancing, false if heartbeat checks
246  *	Cross-call handler to reset heartbeat state just prior to
247  *	enabling heartbeat checks.
262  *	Set the maximum period, in seconds, for heartbeat checks.
267  *	  all CPUs' heartbeat uptime caches are up-to-date before
285 	 * If we're enabling heartbeat checks, make sure we have a
304 	 * Once the heartbeat state has been updated on all (online)
305 	 * CPUs, set the period.  At this point, heartbeat checks can
315  *	Sysctl handler for sysctl kern.heartbeat.max_period.  Verifies
343 	 * Success!  Set the period.  This enables heartbeat checks if
357  *	Set up the kern.heartbeat.* sysctl subtree.
359 SYSCTL_SETUP(sysctl_heartbeat_setup, "sysctl kern.heartbeat setup")
366 	/* kern.heartbeat */
369 	    CTLTYPE_NODE, "heartbeat",
370 	    SYSCTL_DESCR("Kernel heartbeat parameters"),
374 		printf("%s: failed to create kern.heartbeat: %d\n",
379 	/* kern.heartbeat.max_period */
387 		printf("%s: failed to create kern.heartbeat.max_period: %d\n",
403  *	to detect a missed heartbeat.
418  *	Start system heartbeat monitoring.
434 	 * Now that the softint is established, kick off heartbeat
538  *	Select another CPU to check the heartbeat of.  Returns NULL if
603  * heartbeat()
605  *	1. Count a heartbeat on the local CPU.
616  *	5. Select another CPU to check the heartbeat of.
622 heartbeat(void)
631 	 * If heartbeat checks are disabled globally, or if they are
644 	 * Count a heartbeat on this CPU.
663 		 * Our own heartbeat count can't roll back, and
697 	 * so the next call to heartbeat, on this or another CPU, can
703 	 * Select a patient to check the heartbeat of.  If there's no
734  *	Print the heartbeat data of all CPUs.  Can be called from ddb.