Add new ktrace records for the start and end of VM faults. This gives

a pair of records similar to syscall entry and return that a user can
use to determine how long page faults take.  The new ktrace records are
enabled via the 'p' trace type, and are enabled in the default set of
trace points.

Reviewed by:	kib
MFC after:	2 weeks

1 files changed, 40 insertions, 0 deletions

diff --git a/sys/kern/kern_ktrace.c b/sys/kern/kern_ktrace.c
index 2c6e36c..363b8b8 100644
--- a/sys/kern/kern_ktrace.c
+++ b/sys/kern/kern_ktrace.c
@@ -101,6 +101,8 @@ struct ktr_request {
 		struct	ktr_genio ktr_genio;
 		struct	ktr_psig ktr_psig;
 		struct	ktr_csw ktr_csw;
+		struct	ktr_fault ktr_fault;
+		struct	ktr_faultend ktr_faultend;
 	} ktr_data;
 	STAILQ_ENTRY(ktr_request) ktr_list;
 };
@@ -119,6 +121,8 @@ static int data_lengths[] = {
 	sizeof(struct ktr_proc_ctor),		/* KTR_PROCCTOR */
 	0,					/* KTR_PROCDTOR */
 	sizeof(struct ktr_cap_fail),		/* KTR_CAPFAIL */
+	sizeof(struct ktr_fault),		/* KTR_FAULT */
+	sizeof(struct ktr_faultend),		/* KTR_FAULTEND */
 };
 
 static STAILQ_HEAD(, ktr_request) ktr_free;
@@ -791,6 +795,42 @@ ktrcapfail(type, needed, held)
 	ktr_enqueuerequest(td, req);
 	ktrace_exit(td);
 }
+
+void
+ktrfault(vaddr, type)
+	vm_offset_t vaddr;
+	int type;
+{
+	struct thread *td = curthread;
+	struct ktr_request *req;
+	struct ktr_fault *kf;
+
+	req = ktr_getrequest(KTR_FAULT);
+	if (req == NULL)
+		return;
+	kf = &req->ktr_data.ktr_fault;
+	kf->vaddr = vaddr;
+	kf->type = type;
+	ktr_enqueuerequest(td, req);
+	ktrace_exit(td);
+}
+
+void
+ktrfaultend(result)
+	int result;
+{
+	struct thread *td = curthread;
+	struct ktr_request *req;
+	struct ktr_faultend *kf;
+
+	req = ktr_getrequest(KTR_FAULTEND);
+	if (req == NULL)
+		return;
+	kf = &req->ktr_data.ktr_faultend;
+	kf->result = result;
+	ktr_enqueuerequest(td, req);
+	ktrace_exit(td);
+}
 #endif /* KTRACE */
 
 /* Interface and common routines */