remove \n from panics, and use rdtsc() directly to avoid unnecessary indirection.
need to submit additional patch to make perfticks return uvlong.

Reference: /n/patches.lsub.org/patch/trapnits.1
Date: Sun Oct 28 18:36:58 CET 2012
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/k10/trap.c	Thu Jul 12 10:53:55 2012
+++ /sys/src/nix/k10/trap.c	Sun Oct 28 17:40:48 2012
@@ -7,7 +7,6 @@
 
 #include	<tos.h>
 #include	"ureg.h"
-#include	"../port/pmc.h"
 
 #include	"io.h"
 #include	"amd64.h"
@@ -17,8 +16,8 @@
 static void debugbpt(Ureg*, void*);
 static void faultamd64(Ureg*, void*);
 static void doublefault(Ureg*, void*);
-static void ipihdler(Ureg*, void*);
 static void unexpected(Ureg*, void*);
+static void expected(Ureg*, void*);
 static void dumpstackwithureg(Ureg*);
 
 static Lock vctllock;
@@ -158,7 +157,7 @@
 	Vctl *v;
 
 	if(vno < 0 || vno >= 256)
-		panic("trapenable: vno %d\n", vno);
+		panic("trapenable: vno %d", vno);
 	v = malloc(sizeof(Vctl));
 	v->type = "trap";
 	v->tbdf = BUSUNKNOWN;
@@ -202,8 +201,8 @@
 	trapenable(VectorBPT, debugbpt, 0, "#BP");
 	trapenable(VectorPF, faultamd64, 0, "#PF");
 	trapenable(Vector2F, doublefault, 0, "#DF");
-	intrenable(IdtIPI, ipihdler, 0, BUSUNKNOWN, "#IPI");
 	trapenable(Vector15, unexpected, 0, "#15");
+	trapenable(IdtIPI, expected, 0, "#IPI");
 	nmienable();
 
 	addarchfile("irqalloc", 0444, irqallocread, nil);
@@ -250,9 +249,9 @@
 void
 intrtime(int vno)
 {
-	ulong diff, x;		/* should be uvlong */
+	uvlong diff, x;
 
-	x = perfticks();
+	x = rdtsc();
 	diff = x - m->perf.intrts;
 	m->perf.intrts = x;
 
@@ -264,20 +263,12 @@
 	intrtimes[vno].count++;
 }
 
-static void
-pmcnop(Mach *)
-{
-}
-
-void (*_pmcupdate)(Mach *m) = pmcnop;
-
 /* go to user space */
 void
 kexit(Ureg*)
 {
  	uvlong t;
 	Tos *tos;
-	Mach *mp;
 
 	/*
 	 * precise time accounting, kernel exit
@@ -288,18 +279,12 @@
 	tos->kcycles += t - up->kentry;
 	tos->pcycles = up->pcycles;
 	tos->pid = up->pid;
-	if (up->ac != nil)
-		mp = up->ac;
-	else
-		mp = m;
-	tos->core = mp->machno;	
-	tos->nixtype = mp->nixrole;
-	_pmcupdate(m);	
+	tos->core = m->machno;	
 	/*
 	 * The process may change its core.
 	 * Be sure it has the right cyclefreq.
 	 */
-	tos->cyclefreq = mp->cyclefreq;
+	tos->cyclefreq = m->cyclefreq;
 }
 
 void
@@ -334,17 +319,15 @@
 
 	vno = ureg->type;
 
-	m->perf.intrts = perfticks();
+	m->perf.intrts = rdtsc();
 	user = userureg(ureg);
-	if(user && (m->nixrole == NIXTC)){
+	if(user){
 		up->dbgreg = ureg;
 		cycles(&up->kentry);
 	}
 
 	clockintr = 0;
 
-	_pmcupdate(m);
-
 	if(ctl = vctl[vno]){
 		if(ctl->isintr){
 			m->intr++;
@@ -412,21 +395,12 @@
 		}
 		if(vno < nelem(excname))
 			panic("%s", excname[vno]);
-		panic("unknown trap/intr: %d\n", vno);
+		panic("unknown trap/intr: %d", vno);
 	}
 	splhi();
 
 	/* delaysched set because we held a lock or because our quantum ended */
 	if(up && up->delaysched && clockintr){
-		if(0)
-		if(user && up->ac == nil && up->nqtrap == 0 && up->nqsyscall == 0){
-			if(!waserror()){
-				up->ac = getac(up, -1);
-				poperror();
-				runacore();
-				return;
-			}
-		}
 		sched();
 		splhi();
 	}
@@ -468,7 +442,7 @@
 	iprint("r15\t%#16.16llux\n", ureg->r15);
 	iprint("ds  %#4.4ux   es  %#4.4ux   fs  %#4.4ux   gs  %#4.4ux\n",
 		ureg->ds, ureg->es, ureg->fs, ureg->gs);
-	iprint("ureg fs\t%#ux\n", *(unsigned int *)&ureg->ds);
+	iprint("ureg fs\t%#ux\n", *(u32int*)&ureg->ds);
 	iprint("type\t%#llux\n", ureg->type);
 	iprint("error\t%#llux\n", ureg->error);
 	iprint("pc\t%#llux\n", ureg->ip);
@@ -477,8 +451,8 @@
 	iprint("sp\t%#llux\n", ureg->sp);
 	iprint("ss\t%#llux\n", ureg->ss);
 	iprint("type\t%#llux\n", ureg->type);
-	iprint("FS\t%#llux\n", rdmsr(FSbase));
-	iprint("GS\t%#llux\n", rdmsr(GSbase));
+	iprint("fs\t%#llux\n", rdmsr(FSbase));
+	iprint("gs\t%#llux\n", rdmsr(GSbase));
 
 	iprint("m\t%#16.16p\nup\t%#16.16p\n", m, up);
 }
@@ -595,12 +569,8 @@
 }
 
 static void
-ipihdler(Ureg*, void*)
+expected(Ureg*, void*)
 {
-	coherence();
-	if(isbooting(m) && m->proc == nil){
-			tcquiesce();
-	}
 }
 
 static void
@@ -612,8 +582,8 @@
 
 	addr = m->cr2;
 	user = userureg(ureg);
-//	if(!user && mmukmapsync(addr))
-//		return;
+	if(!user && vmapsync(addr) == 0)
+		return;
 
 	/*
 	 * There must be a user context.
@@ -621,7 +591,7 @@
 	 * initialisation before the system is fully up.
 	 */
 	if(up == nil){
-		panic("fault with up == nil; pc %#llux addr %#llux\n",
+		panic("fault with up == nil; pc %#llux addr %#llux",
 			ureg->ip, addr);
 	}
 	read = !(ureg->error & 2);
@@ -642,7 +612,7 @@
 		 * the game's a bogey.
 		 */
 		if(!user && (!insyscall || up->nerrlab == 0))
-			panic("fault: %#llux\n", addr);
+			panic("fault: %#llux", addr);
 		sprint(buf, "sys: trap: fault %s addr=%#llux",
 			read? "read": "write", addr);
 		postnote(up, 1, buf, NDebug);
@@ -698,6 +668,8 @@
 {
 	ureg->ip = p->sched.pc;
 	ureg->sp = p->sched.sp+BY2SE;
+	ureg->r14 = (uvlong)p;
+	ureg->r15 = (uvlong)m;		/* well, better than nothing */
 }
 
 uintptr