# HG changeset patch
# User Noah Evans <npe@plan9.bell-labs.com>
# Date 1307433355 0
# Node ID a190075dcebe024485223221b3bf7ed5a97029ff
# Parent  fe4562cb325e009955324bf228ed22345eb1234e
daily push: Mon Jun 6 09:55:49 CET 2011

diff -r fe4562cb325e -r a190075dcebe src/9kron/TODO
--- a/src/9kron/TODO	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/TODO	Tue Jun 07 07:55:55 2011 +0000
@@ -1,11 +1,5 @@
-- finishing testing/merging the new interface  (rfork|procctl)
-	esoriano
-- 2M pages
-	nemo
 - >128M physical memory
-	ron
 - counters
-	paurea
 - smp for regular kernel
 - send multiple sipis to cores
 - change core roles
diff -r fe4562cb325e -r a190075dcebe src/9kron/k8/acore.c
--- a/src/9kron/k8/acore.c	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/k8/acore.c	Tue Jun 07 07:55:55 2011 +0000
@@ -41,6 +41,23 @@
 ACVctl *acvctl[256];
 
 /*
+ * Check if the AC kernel (mach) stack has more than 4*KiB free.
+ * Do not call panic, the stack is gigantic.
+ */
+static void
+acstackok(void)
+{
+	char dummy;
+	char *sstart;
+
+	sstart = (char *)m - PGSZ - 4*PTPGSZ - MACHSTKSZ;
+	if(&dummy < sstart + 4*KiB){
+		print("ac kernel stack overflow, cpu%d stopped\n", m->machno);
+		DONE();
+	}
+}
+
+/*
  * Main scheduling loop done by the application core.
  * Some of functions run will not return.
  * The system call handler will reset the stack and
@@ -48,11 +65,13 @@
  * We loop because some functions may return and we should
  * wait for another call.
  */
+
 void
 acsched(void)
 {
 	acmmuswitch();
 	for(;;){
+		acstackok();
 		m->load = 0;
 		while(*m->icc->fn == nil)
 			;
diff -r fe4562cb325e -r a190075dcebe src/9kron/k8/fns.h
--- a/src/9kron/k8/fns.h	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/k8/fns.h	Tue Jun 07 07:55:55 2011 +0000
@@ -25,6 +25,8 @@
 int	dbgprint(char*, ...);
 int	decref(Ref*);
 void	delay(int);
+void	dumpmmu(Proc*);
+void	dumpptepg(int lvl,uintptr pa);
 #define	evenaddr(x)				/* x86 doesn't care */
 int	fpudevprocio(Proc*, void*, long, uintptr, int);
 void	fpuinit(void);
@@ -35,6 +37,7 @@
 void	fpusysprocsetup(Proc*);
 void	fpusysrfork(Ureg*);
 void	fpusysrforkchild(Proc*, Proc*);
+Mach*	getac(Proc *, int);
 char*	getconf(char*);
 void	halt(void);
 void hardhalt(void);
@@ -64,6 +67,7 @@
 int	ioalloc(int, int, int, char*);
 int	ioreserve(int, int, int, char*);
 int	iprint(char*, ...);
+void	iprintva(char *tag, uintptr pa);
 int	isaconfig(char*, int, ISAConf*);
 void	kbdenable(void);
 void	kbdinit(void);
@@ -114,8 +118,8 @@
 void	pcisetioe(Pcidev*);
 void	pcisetmwi(Pcidev*);
 int	pcisetpms(Pcidev*, int);
-int	pickac(Proc *, int);
 void	printcpufreq(void);
+void	putac(Mach*);
 void	runapcore(int);
 int	screenprint(char*, ...);			/* debugging */
 void	sfence(void);
@@ -124,7 +128,7 @@
 u64int	spllo(void);
 void	splx(u64int);
 void	splxpc(u64int);
-void	stopac(Proc *);
+void	stopac(void);
 void	syncclock(void);
 void syscall(int scallnr, Ureg* ureg);
 void*	sysexecregs(uintptr, ulong, ulong);
@@ -227,3 +231,9 @@
  * sipi.c
  */
 extern void sipi(void);
+
+/*
+ * debug
+ */
+void HERE(void);
+void DONE(void);
diff -r fe4562cb325e -r a190075dcebe src/9kron/k8/l64v.s
--- a/src/9kron/k8/l64v.s	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/k8/l64v.s	Tue Jun 07 07:55:55 2011 +0000
@@ -289,7 +289,6 @@
 	JNZ	_semainc
 
 	MOVL	BX, AX
-	CMPL	AX, $0				/* overflow if -ve or 0 */
 	RET
 
 /*
@@ -306,7 +305,6 @@
 	JNZ	_semadec
 
 	MOVL	BX, AX
-
 	RET
 
 TEXT adec(SB), 1, $-4				/* int adec(int*); */
diff -r fe4562cb325e -r a190075dcebe src/9kron/k8/main.c
--- a/src/9kron/k8/main.c	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/k8/main.c	Tue Jun 07 07:55:55 2011 +0000
@@ -182,6 +182,23 @@
 }
 
 void
+DONE(void)
+{
+	print("DONE\n");
+	prflush();
+	delay(10000);
+	ndnr();
+}
+
+void
+HERE(void)
+{
+	print("here\n");
+	prflush();
+	delay(5000);
+}
+
+void
 main(u32int ax, u32int bx)
 {
 	vlong hz;
@@ -225,7 +242,7 @@
 	active.exiting = 0;
 
 	fmtinit();
-	print("\nPlan 9\n");
+	print("\nNIX with 4K pages\n");
 	if(vflag){
 		print("&ax = %#p, ax = %#ux, bx = %#ux\n", &ax, ax, bx);
 		multiboot(ax, bx, vflag);
@@ -320,6 +337,7 @@
 			ksetenv("service", "cpu", 0);
 		else
 			ksetenv("service", "terminal", 0);
+		ksetenv("pgsz", "4096", 0);
 		confsetenv();
 		poperror();
 	}
@@ -446,9 +464,8 @@
 	conf.nproc = 100 + ((conf.npage*BY2PG)/MB)*5;
 	if(cpuserver)
 		conf.nproc *= 3;
-	if(conf.nproc > 2000)
-//		conf.nproc = 2000;
-conf.nproc = 1000;
+	if(conf.nproc > 1000)
+		conf.nproc = 1000;
 	conf.nimage = 200;
 	conf.nswap = conf.nproc*80;
 	conf.nswppo = 4096;
diff -r fe4562cb325e -r a190075dcebe src/9kron/k8/mem.h
--- a/src/9kron/k8/mem.h	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/k8/mem.h	Tue Jun 07 07:55:55 2011 +0000
@@ -36,6 +36,11 @@
 #define STACKALIGN(sp)	((sp) & ~(BY2SE-1))	/* bug: assure with alloc */
 
 /*
+ * 2M pages (user segments alignment only)
+ */
+#define	BIGPGSZ		(2ULL*MiB)
+
+/*
  * Time
  */
 #define HZ		(100)			/* clock frequency */
@@ -49,7 +54,7 @@
  *  Kernel is at ??
  */
 #define UTZERO		(0+2*MiB)		/* first address in user text */
-#define UTROUND(t)	ROUNDUP((t), 2*MiB)
+#define UTROUND(t)	ROUNDUP((t), BIGPGSZ)
 #define USTKTOP		0x00007ffffffff000ull
 #define USTKSIZE	(16*1024*1024)		/* size of user stack */
 #define TSTKTOP		(USTKTOP-USTKSIZE)	/* end of new stack in sysexec */
@@ -80,7 +85,6 @@
 
 #define getpgcolor(a)	0
 
-
 /*
  * Oh, give it a fucking rest, will you.
  */
diff -r fe4562cb325e -r a190075dcebe src/9kron/k8/mkfile
--- a/src/9kron/k8/mkfile	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/k8/mkfile	Tue Jun 07 07:55:55 2011 +0000
@@ -2,7 +2,8 @@
 CONFLIST=k8aoe k8cpu k8root
 
 HACK=`{ bind -c ../libc /sys/src/libc;\
-	bind  ../include/libc.h /sys/include/libc.h}
+	unmount /sys/include>[2]/dev/null;\
+	bind  -b ../include /sys/include}
 
 objtype=amd64
 </$objtype/mkfile
diff -r fe4562cb325e -r a190075dcebe src/9kron/k8/mmu.c
--- a/src/9kron/k8/mmu.c	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/k8/mmu.c	Tue Jun 07 07:55:55 2011 +0000
@@ -6,7 +6,7 @@
 
 #include "amd64.h"
 
-#define PTEX(pi, l)	(((pi)>>((((l)-1)*9)+12)) & ((1<<PTPGSHFT)-1))
+#define PTEX(pi, lvl)	(((pi)>>((((lvl)-1)*9)+12)) & ((1<<PTPGSHFT)-1))
 
 static Page mach0pml4;
 
@@ -14,16 +14,32 @@
  * Nemo: NB:
  * m->pml4 is always the same.
  * sched->procsave->flushtbl zeroes the entries in pml4 up to
- * pml4->daddr (which is the number of entries used by the user).
+ * pml4->daddr (which is the number of entries used by the user, or
+ * the index in the upper page table for this entry)
  * the new process will fault and we populate again the page table
  * as needed.
  *
+ * mmuptp[0] is used to keep a free list of pages.
+ * mmuptp[1-3] are used to keep PT pages for each level
+ * 4K pages: pml4 -> lvl3 -> lvl2 -> lvl1 ->pg
+ * 2M pages: pml4 -> lvl3 -> lvl2 -> pg
+ *
  * Therefore, we can't use pml4 in other processors. Each one
  * has to play the same trick at least, using its own pml4.
  * For NIX, we have to fill up the pml4 of the application core
  * so it wont fault.
  */
 
+void
+iprintva(char *s, uintptr addr)
+{
+	iprint("%s = %#ullx = %#ullx:%#ullx:%#ullx:%#ullx:%#ullx", s, addr,
+			(addr >> (12+9+9+9)) & 0x1FF,
+			(addr >> (12+9+9)) & 0x1FF,
+			(addr >> (12+9)) & 0x1FF,
+			(addr >> 12) & 0x1FF,
+			addr & 0xFFF);
+}
 
 void
 mmuinit(void)
@@ -35,7 +51,9 @@
 	if(m->machno == 0)
 		page = &mach0pml4;
 	else{
-		/* NIX: KLUDGE: Has to go when each mach is using its own page table */
+		/* NIX: KLUDGE: Has to go when each mach is using
+		 * its own page table
+		 */
 		p = UINT2PTR(m->stack);
 		p += MACHSTKSZ;
 		memmove(p, UINT2PTR(mach0pml4.va), PTPGSZ);
@@ -110,6 +128,56 @@
 	m->pml4->daddr = 0;
 }
 
+static void
+tabs(int n)
+{
+	int i;
+
+	for(i = 0; i < n; i++)
+		print("  ");
+}
+
+void
+dumpptepg(int lvl, uintptr pa)
+{
+	PTE *pte;
+	int tab, i;
+
+	tab = 4 - lvl;
+	pte = UINT2PTR(KADDR(pa));
+	for(i = 0; i < PTPGSZ/sizeof(PTE); i++)
+		if(pte[i] & PteP){
+			tabs(tab);
+			print("l%d[%#05x]:\t%#ullx\n", lvl, i, pte[i]);
+			if(lvl == 3 && i == 0x1FF){
+				/* don't print lvl 2 kernel entries */
+				tabs(tab+1);
+				print("...kern...\n");
+				continue;
+			}
+			if(lvl > 2 || (lvl == 2 && (pte[i]&PtePS) == 0))
+				dumpptepg(lvl-1, PPN(pte[i]));
+		}
+	print("\n");
+}
+
+void
+dumpmmu(Proc *p)
+{
+	int i;
+	Page *pg;
+
+	print("proc %#p\n", p);
+	for(i = 3; i > 0; i--){
+		print("mmuptp[%d]:\n", i);
+		for(pg = p->mmuptp[i]; pg != nil; pg = pg->next)
+			print("\tva %#ullx ppn %#ullx d %#ulx\n",
+				pg->va, pg->pa, pg->daddr);
+	}
+	print("pml4 %#ullx\n", m->pml4->pa);
+	dumpptepg(4, m->pml4->pa);
+}
+
 void
 mmuswitch(Proc* proc)
 {
diff -r fe4562cb325e -r a190075dcebe src/9kron/k8/pmcio.c
--- a/src/9kron/k8/pmcio.c	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/k8/pmcio.c	Tue Jun 07 07:55:55 2011 +0000
@@ -188,7 +188,7 @@
 	return ns;
 }
 
-int
+u64int
 pmcgetctr(u32int regno)
 {
 	return rdmsr(regno + PerfCtrbase);
diff -r fe4562cb325e -r a190075dcebe src/9kron/k8/syscall.c
--- a/src/9kron/k8/syscall.c	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/k8/syscall.c	Tue Jun 07 07:55:55 2011 +0000
@@ -125,6 +125,9 @@
 	uintptr sp;
 	NFrame *nf;
 
+	/*
+	 * Calls procctl splhi, see comment in procctl for the reasoning.
+	 */
 	if(up->procctl)
 		procctl(up);
 	if(up->nnote == 0)
@@ -266,6 +269,7 @@
 		systab[scallnr].f(&ar0, (va_list)up->arg);
 		if(scallnr == SYSR1){
 			/*
+			 * BUG: must go when ron binaries go.
 			 * NIX: Returning from execac().
 			 * This means that the process is back to the
 			 * time sharing core. However, the process did
diff -r fe4562cb325e -r a190075dcebe src/9kron/k8/tcore.c
--- a/src/9kron/k8/tcore.c	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/k8/tcore.c	Tue Jun 07 07:55:55 2011 +0000
@@ -12,7 +12,6 @@
 
 Lock nixaclock;	/* NIX AC lock; held while assigning procs to cores */
 
-
 /*
  * NIX support for the time sharing core.
  */
@@ -20,14 +19,15 @@
 extern void actrapret(void);
 extern void acsysret(void);
 
-int
-pickac(Proc *p, int core)
+Mach*
+getac(Proc *p, int core)
 {
 	int i;
 	Mach *mp;
 
+	mp = nil;
 	if(core == 0)
-		panic("can't pickac for a TC");
+		panic("can't getac for a TC");
 	lock(&nixaclock);
 	if(waserror()){
 		unlock(&nixaclock);
@@ -43,7 +43,6 @@
 			error("core is not an AC");
 	Found:
 		mp->proc = p;
-		p->ac = mp;
 	}else{
 		for(i = 1; i < MAXMACH; i++){
 			mp = sys->machptr[i];
@@ -55,7 +54,7 @@
 	}
 	unlock(&nixaclock);
 	poperror();
-	return core;
+	return mp;
 }
 
 /*
@@ -64,10 +63,9 @@
  * or we must be prepared for nesting them, which we are not.
  * This is important for note handling, because postnote()
  * assumes that it's ok to send an IPI to an AC, no matter its
- * state.
+ * state. The /proc interface also assumes that.
  * 
  */
-
 void
 intrac(Proc *p)
 {
@@ -86,23 +84,32 @@
 }
 
 void
-stopac(Proc *p)
+putac(Mach *m)
+{
+	mfence();
+	m->proc = nil;
+}
+
+void
+stopac(void)
 {
 	Mach *mp;
 
-	mp = p->ac;
+	mp = up->ac;
 	if(mp == nil)
 		return;
-	if(mp->proc != p)
+	if(mp->proc != up)
 		panic("stopac");
 
 	lock(&nixaclock);
-	p->ac = nil;
+	up->ac = nil;
 	mp->proc = nil;
 	unlock(&nixaclock);
 
-//	send ipi to p->ac, it would rerun squidboy(), and
-//	wait for us to give it a function to run.
+	/* TODO:
+	 * send sipi to up->ac, it would rerun squidboy(), and
+	 * wait for us to give it a function to run.
+	 */
 }
 
 /*
@@ -232,26 +239,19 @@
 		case ICCTRAP:
 			s = splhi();
 			m->cr2 = up->ac->cr2;
-iprint("runacore: entering icctrap %ulld cr2 %#ullx ureg %#p\n", ureg->type, m->cr2, ureg);
 			DBG("runacore: trap %ulld cr2 %#ullx ureg %#p\n",
 				ureg->type, m->cr2, ureg);
 			switch(ureg->type){
 			case IdtIPI:
 				if(up->procctl || up->nnote)
 					notify(up->dbgreg);
-				if(up->ac == nil){
-					/*
-					 *  to procctl, then syscall,  to 
-					 *  be back in the TC
-					 */
-iprint("runacore: returning, from icctrap ipi\n");
-					return;
-				}
+				if(up->ac == nil)
+					goto ToTC;
 				kexit(up->dbgreg);
 				break;
-			case IdtPF:
 			case IdtNM:
 			case IdtMF:
+			case IdtXF:
 				/* these are handled in the AC;
 				 * If we get here, they left in m->icc->data
 				 * a note to be posted to the process.
@@ -274,24 +274,23 @@
 			DBG("runacore: syscall ax %#ullx ureg %#p\n",
 				ureg->ax, ureg);
 			cr3put(m->pml4->pa);
-iprint("runacore: syscall %#ullx \n", ureg->ax);
 			syscall(ureg->ax, ureg);
 			flush = 1;
 			fn = acsysret;
-			if(up->ac == nil){
-				/*
-				 *  to procctl, then syscall,  to 
-				 *  be back in the TC
-				 */
-iprint("runacore: returning, from syscall\n");
-				return;	
-			}
+			if(up->ac == nil)
+				goto ToTC;
 			break;
 		default:
 			panic("runacore: unexpected rc = %d", rc);
 		}
 		rc = runac(up->ac, fn, flush, nil, 0);
 	}
+ToTC:
+	/*
+	 *  to procctl, then syscall,  to 
+	 *  be back in the TC
+	 */
+	DBG("runacore: up %#p: return\n", up);
 }
 
 extern ACVctl *acvctl[];
diff -r fe4562cb325e -r a190075dcebe src/9kron/libc/9sys/upsem.c
--- a/src/9kron/libc/9sys/upsem.c	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/libc/9sys/upsem.c	Tue Jun 07 07:55:55 2011 +0000
@@ -42,7 +42,7 @@
 	typesok();
 	n = ainc(s);
 	dprint(2, "upsem: %#p = %d\n", s, n);
-	if(n < 0){
+	if(n <= 0){
 		ainc(&c.kup);
 		semwakeup(s);
 	}else
diff -r fe4562cb325e -r a190075dcebe src/9kron/libc/port/mkfile
--- a/src/9kron/libc/port/mkfile	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/libc/port/mkfile	Tue Jun 07 07:55:55 2011 +0000
@@ -31,7 +31,6 @@
 	getcallerpc.c\
 	getfields.c\
 	getuser.c\
-	getcore.c\
 	hangup.c\
 	hypot.c\
 	lnrand.c\
diff -r fe4562cb325e -r a190075dcebe src/9kron/port/devproc.c
--- a/src/9kron/port/devproc.c	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/port/devproc.c	Tue Jun 07 07:55:55 2011 +0000
@@ -1546,21 +1546,23 @@
 		break;
 	case CMcore:
 		core = atoi(cb->f[1]);
-		if(core < 0 || core >= MAXMACH)
+		if(core >= MAXMACH)
 			error("wrong core number");
 		else if(core == 0){
-			if(p->ac != nil){
-				p->procctl = Proc_totc;
-				if(p != up && p->state == Exotic){
-					/* see the comment in postnote */
-					intrac(p);
-				}
-			}else
-				error("the proc is not running in an ac");
+			if(p->ac == nil)
+				error("not running in an ac");
+			p->procctl = Proc_totc;
+			if(p != up && p->state == Exotic){
+				/* see the comment in postnote */
+				intrac(p);
+			}
 		}else{
 			if(p->ac != nil)
-				error("proc already running in an ac");
-			pickac(p, core);
+				error("running in an ac");
+			if(core < 0)
+				p->ac = getac(p, -1);
+			else
+				p->ac = getac(p, core);
 			p->procctl = Proc_toac;
 			p->prepagemem = 1;
 		}
diff -r fe4562cb325e -r a190075dcebe src/9kron/port/page.c
--- a/src/9kron/port/page.c	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/port/page.c	Tue Jun 07 07:55:55 2011 +0000
@@ -16,7 +16,6 @@
 struct	Palloc palloc;
 struct	Palloc bigpalloc;
 
-#define	BIGPGSZ		(2ULL*MiB)
 #define	BIGPGSHFT	21U
 #define	BIGPGROUND(x)	ROUNDUP((x), BIGPGSZ)
 #define	PGSPERBIG	(BIGPGSZ/PGSZ)
@@ -69,11 +68,13 @@
 			palloc.user++;
 		}
 		palloc.tail = lastp;
-print("pm %d base %#ullx npgs %#ulx\n", i, pm->base, pm->npage);
 
 		base = BIGPGROUND(pm->base);
 		print("bigbase %#ullx\n", base);
-if(0)
+if(1){
+USED(bigp);
+USED(pmp0);
+}else
 		for(j = (base-pm->base)/PGSZ; j + PGSPERBIG < pm->npage; ){
 			/*
 			 * unlink all pages within a big page.
@@ -294,7 +295,7 @@
 	}
 
 	/* First try for our colour */
-	for(p = palloc.head; p; p = p->next)
+	for(p = pp->head; p; p = p->next)
 		if(p->color == color)
 			break;
 
diff -r fe4562cb325e -r a190075dcebe src/9kron/port/pmc.h
--- a/src/9kron/port/pmc.h	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/port/pmc.h	Tue Jun 07 07:55:55 2011 +0000
@@ -27,7 +27,7 @@
 int		pmcgetctl(Pmc *p, u32int regno);
 int		pmcdescstr(char *str, int nstr);
 int		pmcctlstr(char *str, int nstr, Pmc *p);
-int		pmcgetctr(u32int regno);
+u64int	pmcgetctr(u32int regno);
 int		pmcsetctr(u64int v, u32int regno);
 
 int		pmcanyenab(void);
diff -r fe4562cb325e -r a190075dcebe src/9kron/port/proc.c
--- a/src/9kron/port/proc.c	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/port/proc.c	Tue Jun 07 07:55:55 2011 +0000
@@ -78,7 +78,7 @@
 			break;
 		case Moribund:
 			up->state = Dead;
-			stopac(up);
+			stopac();
 			edfstop(up);
 			if (up->edf)
 				free(up->edf);
@@ -103,13 +103,19 @@
 	sched();
 }
 
+/*
+ * Check if the stack has more than 4*KiB free.
+ * Do not call panic, the stack is gigantic.
+ */
 static void
 stackok(void)
 {
 	char dummy;
 
-	if(&dummy < (char*)up->kstack + 4*KiB)
-		panic("kernel stack overflow");
+	if(&dummy < (char*)up->kstack + 4*KiB){
+		print("tc kernel stack overflow, cpu%d stopped\n", m->machno);
+		DONE();
+	}
 }
 
 /*
@@ -989,7 +995,7 @@
 	broken.p[broken.n++] = p;
 	qunlock(&broken);
 
-	stopac(up);
+	stopac();
 	edfstop(up);
 	p->state = Broken;
 	p->psstate = 0;
@@ -1174,7 +1180,7 @@
 	lock(&procalloc);
 	lock(&palloc);
 
-	stopac(up);
+	stopac();
 	edfstop(up);
 	up->state = Moribund;
 	sched();
@@ -1436,12 +1442,16 @@
 		 * by moving to a core, but never returns (unless
 		 * the process gets moved back to a TC.)
 		 */
+		spllo();
 		runacore();
 		return;
 
 	case Proc_totc:
 		p->procctl = 0;
-		stopac(p);
+		if(p != up)
+			panic("procctl: stopac: p != up");
+		spllo();
+		stopac();
 		return;
 	}
 }
diff -r fe4562cb325e -r a190075dcebe src/9kron/port/segment.c
--- a/src/9kron/port/segment.c	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/port/segment.c	Tue Jun 07 07:55:55 2011 +0000
@@ -202,7 +202,7 @@
 	Page **pg;
 
 	if(p->va < s->base || p->va >= s->top)
-		panic("segpage");
+		panic("segpage: p->va < s->base || p->va >= s->top");
 
 	soff = p->va - s->base;
 	pte = &s->map[soff/PTEMAPMEM];
diff -r fe4562cb325e -r a190075dcebe src/9kron/port/syscallfmt.c
--- a/src/9kron/port/syscallfmt.c	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/port/syscallfmt.c	Tue Jun 07 07:55:55 2011 +0000
@@ -61,7 +61,7 @@
 	void *v;
 	vlong vl;
 	uintptr p;
-	int i[2], len;
+	int i[2], len, **ip;
 	char *a, **argv;
 
 	fmtstrinit(&fmt);
@@ -109,6 +109,22 @@
 		l = va_arg(list, unsigned long);
 		fmtprint(&fmt, "%#lud ", l);
 		break;
+	case EXECAC:
+		i[0] = va_arg(list, int);
+		fmtprint(&fmt, "%d", i[0]);
+		a = va_arg(list, char*);
+		fmtuserstring(&fmt, a, " ");
+		argv = va_arg(list, char**);
+		evenaddr(PTR2UINT(argv));
+		for(;;){
+			a = *(char**)validaddr(argv, sizeof(char**), 0);
+			if(a == nil)
+				break;
+			fmtprint(&fmt, " ");
+			fmtuserstring(&fmt, a, "");
+			argv++;
+		}
+		break;
 	case EXEC:
 		a = va_arg(list, char*);
 		fmtuserstring(&fmt, a, "");
@@ -230,6 +246,17 @@
 		i[0] = va_arg(list, int);
 		fmtprint(&fmt, "%#p %d", v, i[0]);
 		break;
+	case SEMSLEEP:
+	case SEMWAKEUP:
+		v = va_arg(list, int*);
+		fmtprint(&fmt, "%#p", v);
+		break;
+	case SEMALT:
+		ip = va_arg(list, int**);
+		i[0] = va_arg(list, int);
+		validaddr(ip, sizeof(int*)*i[0], 0);
+		fmtprint(&fmt, "%#p %d", ip, i[0]);
+		break;
 	case SEEK:
 		v = va_arg(list, vlong*);
 		i[0] = va_arg(list, int);
@@ -327,6 +354,7 @@
 		fmtprint(&fmt, " = %ld", ar0->l);
 		break;
 	case EXEC:
+	case EXECAC:
 	case SEGBRK:
 	case SEGATTACH:
 	case RENDEZVOUS:
diff -r fe4562cb325e -r a190075dcebe src/9kron/port/sysproc.c
--- a/src/9kron/port/sysproc.c	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/port/sysproc.c	Tue Jun 07 07:55:55 2011 +0000
@@ -80,7 +80,7 @@
 		if(flag & (RFPREPAGE|RFCPREPAGE))
 			up->prepagemem = flag&RFPREPAGE;
 		if(flag & RFCORE){
-			pickac(up, -1);
+			up->ac = getac(up, -1);
 			up->procctl = Proc_toac;
 		}else if(flag & RFCCORE){
 			if(up->ac != nil)
@@ -95,7 +95,7 @@
 
 	if(flag & RFCORE){
 		if(!waserror()){
-			pickac(p, -1);
+			p->ac = getac(p, -1);
 			p->procctl = Proc_toac;
 			poperror();
 		}else{
@@ -278,6 +278,7 @@
 	chan = nil;
 	mp = nil;
 	if(waserror()){
+		DBG("execac: failing: %s\n", up->errstr);
 		if(file)
 			free(file);
 		if(elem)
@@ -286,14 +287,17 @@
 			cclose(chan);
 		if(core > 0 && mp != nil)
 			mp->proc = nil;
+		if(core != 0)
+			up->ac = nil;
 		nexterror();
 	}
 
 	if(core != 0)
-		pickac(up, core);
+		up->ac = getac(up, core);
 
 	argc = 0;
 	file = validnamedup(ufile, 1);
+	DBG("execac: up %#p file %s\n", up, file);
 	chan = namec(file, Aopen, OEXEC, 0);
 	kstrdup(&elem, up->genbuf);
 
@@ -607,9 +611,11 @@
 		up->procctl = Proc_toac;
 		up->prepagemem = 1;
 	}
-for(i = 0; i < nelem(up->seg); i++)
-if(up->seg[i] != nil)
-print("after execac: seg %d %#ullx %#ullx\n", i, up->seg[i]->base, up->seg[i]->top);
+
+	DBG("execac up %#p done\n"
+		"textsz %lx datasz %lx bsssz %lx hdrsz %lx\n"
+		"textlim %ullx datalim %ullx bsslim %ullx\n", up,
+		textsz, datasz, bsssz, hdrsz, textlim, datalim, bsslim);
 }
 
 void
diff -r fe4562cb325e -r a190075dcebe src/9kron/port/syssem.c
--- a/src/9kron/port/syssem.c	Thu Jun 02 15:30:20 2011 +0000
+++ b/src/9kron/port/syssem.c	Tue Jun 07 07:55:55 2011 +0000
@@ -142,7 +142,6 @@
 	DBG("semalt up %#p ss[0] %#p\n", up, ss[0]->np);
 	r = -1;
 	for(i = 0; i < n; i++){
-	DBG("semalt1 %#p\n", up);
 		s = ss[i];
 		n = semadec(s->np);
 		if(n >= 0){