Implement the DTrace sched provider. This implementation aims to be

compatible with the sched provider implemented by Solaris and its open-
source derivatives.  Full documentation of the sched provider can be found
on Oracle's DTrace wiki pages.

Note that for compatibility with scripts originally written for Solaris,
serveral probes are defined that will never fire.  These probes are defined
to fire when Solaris-specific features perform certain actions.  As these
features are not present in FreeBSD, the probes can never fire.

Also, I have added a two probes that are not defined in Solaris, lend-pri
and load-change.  These probes have been added to make it possible to
collect schedgraph data with DTrace.

Finally, a few probes are defined in Solaris to take a cpuinfo_t *
argument.  As it was not immediately clear to me how to translate that to
FreeBSD, currently those probes are passed NULL in place of a cpuinfo_t *.

Sponsored by: Sandvine Incorporated
MFC after:	2 weeks

1 files changed, 6 insertions, 0 deletions

diff --git a/sys/kern/kern_clock.c b/sys/kern/kern_clock.c
index 57dd632..5e10200 100644
--- a/sys/kern/kern_clock.c
+++ b/sys/kern/kern_clock.c
@@ -40,6 +40,7 @@ __FBSDID("$FreeBSD$");
 #include "opt_kdb.h"
 #include "opt_device_polling.h"
 #include "opt_hwpmc_hooks.h"
+#include "opt_kdtrace.h"
 #include "opt_ntp.h"
 #include "opt_watchdog.h"
 
@@ -56,6 +57,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/resource.h>
 #include <sys/resourcevar.h>
 #include <sys/sched.h>
+#include <sys/sdt.h>
 #include <sys/signalvar.h>
 #include <sys/sleepqueue.h>
 #include <sys/smp.h>
@@ -88,6 +90,9 @@ SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL);
 /* Spin-lock protecting profiling statistics. */
 static struct mtx time_lock;
 
+SDT_PROVIDER_DECLARE(sched);
+SDT_PROBE_DEFINE2(sched, , , tick, tick, "struct thread *", "struct proc *");
+
 static int
 sysctl_kern_cp_time(SYSCTL_HANDLER_ARGS)
 {
@@ -760,6 +765,7 @@ statclock_cnt(int cnt, int usermode)
 		ru->ru_maxrss = rss;
 	KTR_POINT2(KTR_SCHED, "thread", sched_tdname(td), "statclock",
 	    "prio:%d", td->td_priority, "stathz:%d", (stathz)?stathz:hz);
+	SDT_PROBE2(sched, , , tick, td, td->td_proc);
 	thread_lock_flags(td, MTX_QUIET);
 	for ( ; cnt > 0; cnt--)
 		sched_clock(td);