diff --git a/src/libthread/channel.c b/src/libthread/channel.c
index 14791d0..b488dc9 100644
--- a/src/libthread/channel.c
+++ b/src/libthread/channel.c
@@ -4,7 +4,7 @@
 
 static void enqueue(Alt*, Thread*);
 static void dequeue(Alt*);
-static int altexec(Alt*, int);
+static int altexec(Alt*);
 
 int _threadhighnentry;
 int _threadnalt;
@@ -101,7 +101,7 @@
 {
 	Alt *a, *xa;
 	Channel *c;
-	int n, s;
+	int n;
 	Thread *t;
 
 	/*
@@ -119,7 +119,6 @@
 	t = _threadgetproc()->thread;
 	if((t && t->moribund) || _threadexitsallstatus)
 		yield();	/* won't return */
-	s = _procsplhi();
 	lock(&chanlock);
 
 	/* test whether any channels can proceed */
@@ -134,7 +133,6 @@
 		c = xa->c;
 		if(c==nil){
 			unlock(&chanlock);
-			_procsplx(s);
 			return -1;
 		}
 		if(canexec(xa))
@@ -146,8 +144,7 @@
 		/* nothing can proceed */
 		if(xa->op == CHANNOBLK){
 			unlock(&chanlock);
-			_procsplx(s);
-_threadnalt++;
+			_threadnalt++;
 			return xa - alts;
 		}
 
@@ -172,9 +169,7 @@
 		t->alt = alts;
 		t->chan = Chanalt;
 		t->altrend.l = &chanlock;
-		_procsplx(s);
 		_threadsleep(&t->altrend);
-		s = _procsplhi();
 
 		/* dequeue from channels, find selected one */
 		a = nil;
@@ -187,13 +182,12 @@
 			dequeue(xa);
 		}
 		unlock(&chanlock);
-		_procsplx(s);
 		if(a == nil){	/* we were interrupted */
 			assert(c==(Channel*)~0);
 			return -1;
 		}
 	}else{
-		altexec(a, s);	/* unlocks chanlock, does splx */
+		altexec(a);	/* unlocks chanlock, does splx */
 	}
 	if(t)
 		t->chan = Channone;
@@ -445,7 +439,7 @@
 }
 
 static int
-altexec(Alt *a, int spl)
+altexec(Alt *a)
 {
 	volatile Alt *b;
 	int i, n, otherop;
@@ -492,7 +486,6 @@
 		_threaddebug(DBGCHAN, "chanlock is %lud", *(ulong*)(void*)&chanlock);
 		_threaddebug(DBGCHAN, "unlocking the chanlock");
 		unlock(&chanlock);
-		_procsplx(spl);
 		return 1;
 	}
 
@@ -503,6 +496,5 @@
 		altcopy(buf, me, c->e);
 
 	unlock(&chanlock);
-	_procsplx(spl);
 	return 1;
 }
diff --git a/src/libthread/create.c b/src/libthread/create.c
index d2f4be2..4e6bc6d 100644
--- a/src/libthread/create.c
+++ b/src/libthread/create.c
@@ -138,7 +138,7 @@
 	p = _threadgetproc();
 	np = _newproc();
 	p->newproc = np;
-	p->schedfn = _threadstartproc;
+	p->schedfn = _kthreadstartproc;
 	id = _newthread(np, f, arg, stacksize, nil, p->thread->grp);
 	_sched();	/* call into scheduler to create proc XXX */
 	return id;
diff --git a/src/libthread/exec-unix.c b/src/libthread/exec-unix.c
index f69fedc..e5848ea 100644
--- a/src/libthread/exec-unix.c
+++ b/src/libthread/exec-unix.c
@@ -10,20 +10,9 @@
 	int pfd[2];
 	int n, pid;
 	char exitstr[ERRMAX];
-	static int firstexec = 1;
-	static Lock lk;
 
 	_threaddebug(DBGEXEC, "threadexec %s", prog);
 
-	if(firstexec){
-		lock(&lk);
-		if(firstexec){
-			firstexec = 0;
-			_threadfirstexec();
-		}
-		unlock(&lk);
-	}
-
 	/*
 	 * We want threadexec to behave like exec; if exec succeeds,
 	 * never return, and if it fails, return with errstr set.
@@ -53,7 +42,6 @@
 		_threaddebug(DBGSCHED, "exit after efork");
 		_exit(0);
 	default:
-		_threadafterexec();
 		if(freeargs)
 			free(args);
 		break;
@@ -88,14 +76,14 @@
 void
 threadexec(Channel *pidc, int fd[3], char *prog, char *args[])
 {
-	if(_callthreadexec(pidc, fd, prog, args, 0) >= 0)
+	if(_kthreadexec(pidc, fd, prog, args, 0) >= 0)
 		threadexits(nil);
 }
 
 int
 threadspawn(int fd[3], char *prog, char *args[])
 {
-	return _callthreadexec(nil, fd, prog, args, 0);
+	return _kthreadexec(nil, fd, prog, args, 0);
 }
 
 /*
@@ -128,7 +116,7 @@
 	args[n] = 0;
 	va_end(arg);
 
-	if(_callthreadexec(pidc, fd, f, args, 1) >= 0)
+	if(_kthreadexec(pidc, fd, f, args, 1) >= 0)
 		threadexits(nil);
 }
 
diff --git a/src/libthread/exit.c b/src/libthread/exit.c
index 79aa7c7..69f3f73 100644
--- a/src/libthread/exit.c
+++ b/src/libthread/exit.c
@@ -32,7 +32,7 @@
 	_threadexitsallstatus = exitstr;
 	_threaddebug(DBGSCHED, "_threadexitsallstatus set to %p", _threadexitsallstatus);
 	/* leave */
-	_threadexitallproc(exitstr);
+	_kthreadexitallproc(exitstr);
 }
 
 Channel*
diff --git a/src/libthread/fdwait.c b/src/libthread/fdwait.c
index a46ea45..d398341 100644
--- a/src/libthread/fdwait.c
+++ b/src/libthread/fdwait.c
@@ -7,164 +7,25 @@
 #include <unistd.h>
 #include <fcntl.h>
 
-#define debugpoll 0
-
-#ifdef __APPLE__
-#include <sys/time.h>
-enum { POLLIN=1, POLLOUT=2, POLLERR=4 };
-struct pollfd
+void
+fdwait()
 {
-	int fd;
-	int events;
-	int revents;
-};
-
-int
-poll(struct pollfd *p, int np, int ms)
-{
-	int i, maxfd, n;
-	struct timeval tv, *tvp;
 	fd_set rfd, wfd, efd;
-	
-	maxfd = -1;
+
 	FD_ZERO(&rfd);
 	FD_ZERO(&wfd);
 	FD_ZERO(&efd);
-	for(i=0; i<np; i++){
-		p[i].revents = 0;
-		if(p[i].fd == -1)
-			continue;
-		if(p[i].fd > maxfd)
-			maxfd = p[i].fd;
-		if(p[i].events & POLLIN)
-			FD_SET(p[i].fd,	&rfd);
-		if(p[i].events & POLLOUT)
-			FD_SET(p[i].fd, &wfd);
-		FD_SET(p[i].fd, &efd);
-	}
-
-	if(ms != -1){
-		tv.tv_usec = (ms%1000)*1000;
-		tv.tv_sec = ms/1000;
-		tvp = &tv;
-	}else
-		tvp = nil;
-
-	if(debugpoll){
-		fprint(2, "select %d:", maxfd+1);
-		for(i=0; i<=maxfd; i++){
-			if(FD_ISSET(i, &rfd))
-				fprint(2, " r%d", i);
-			if(FD_ISSET(i, &wfd))
-				fprint(2, " w%d", i);
-			if(FD_ISSET(i, &efd))
-				fprint(2, " e%d", i);
-		}
-		fprint(2, "; tp=%p, t=%d.%d\n", tvp, tv.tv_sec, tv.tv_usec);
-	}
-
-	n = select(maxfd+1, &rfd, &wfd, &efd, tvp);
-
-	if(n <= 0)
-		return n;
-
-	for(i=0; i<np; i++){
-		if(p[i].fd == -1)
-			continue;
-		if(FD_ISSET(p[i].fd, &rfd))
-			p[i].revents |= POLLIN;
-		if(FD_ISSET(p[i].fd, &wfd))
-			p[i].revents |= POLLOUT;
-		if(FD_ISSET(p[i].fd, &efd))
-			p[i].revents |= POLLERR;
-	} 
-	return n;
-}
-
-#else
-#include <poll.h>
-#endif
-
-/*
- * Poll file descriptors in an idle loop.
- */
-
-typedef struct Poll Poll;
-
-struct Poll
-{
-	Channel *c;	/* for sending back */
-};
-
-static Channel *sleepchan[64];
-static int sleeptime[64];
-static int nsleep;
-
-static struct pollfd pfd[64];
-static struct Poll polls[64];
-static int npoll;
-
-static void
-pollidle(void *v)
-{
-	int i, n, t;
-	uint now;
-
-	for(;; yield()){
-		if(debugpoll) fprint(2, "poll %d:", npoll);
-		for(i=0; i<npoll; i++){
-			if(debugpoll) fprint(2, " %d%c", pfd[i].fd, pfd[i].events==POLLIN ? 'r' : 'w');
-			pfd[i].revents = 0;
-		}
-		t = -1;
-		now = p9nsec()/1000000;
-		for(i=0; i<nsleep; i++){
-			n = sleeptime[i] - now;
-			if(debugpoll) fprint(2, " s%d", n);
-			if(n < 0)
-				n = 0;
-			if(t == -1 || n < t)
-				t = n;
-		}
-		if(debugpoll) fprint(2, "; t=%d\n", t);
-	
-		n = poll(pfd, npoll, t);
-		//fprint(2, "poll ret %d:", n);
-		now = p9nsec()/1000000;
-		for(i=0; i<nsleep; i++){
-			if((int)(sleeptime[i] - now) < 0){
-				nbsendul(sleepchan[i], 0);
-				nsleep--;
-				sleepchan[i] = sleepchan[nsleep];
-				sleeptime[i] = sleeptime[nsleep];
-				i--;
-			}
-		}
-				
-		if(n <= 0)
-			continue;
-		for(i=0; i<npoll; i++)
-			if(pfd[i].fd != -1 && pfd[i].revents){
-				//fprint(2, " %d", pfd[i].fd);
-				pfd[i].fd = -1;
-				pfd[i].events = 0;
-				pfd[i].revents = 0;
-				nbsendul(polls[i].c, 1);
-				//fprint(2, " x%d", pfd[i].fd);
-			}
-		//fprint(2, "\n");
-	}
+	if(mode=='w')
+		FD_SET(&wfd, fd);
+	else
+		FD_SET(&rfd, fd);
+	FD_SET(&efd, fd);
+	select(fd+1, &rfd, &wfd, &efd, nil);
 }
 
 void
 threadfdwaitsetup(void)
 {
-	static int setup = 0;
-
-	if(!setup){
-		setup = 1;
-		proccreate(pollidle, nil, 16384);
-	}
 }
 
 void
@@ -199,6 +60,8 @@
 	polls[i].c = &s.c;
 	if(0) fprint(2, "%s [%3d] fdwait %d %c list *0x%lux\n",
 		argv0, threadid(), fd, rw, pc);
+	if(pollpid)
+		postnote(PNPROC, pollpid, "interrupt");
 	recvul(&s.c);
 }
 
diff --git a/src/libthread/main.c b/src/libthread/main.c
index ec08543..bc4efd2 100644
--- a/src/libthread/main.c
+++ b/src/libthread/main.c
@@ -11,12 +11,10 @@
 	char **argv;
 };
 
-int _threadmainpid;
 int mainstacksize;
-int _callsthreaddaemonize;
-static int passtomainpid;
 
 extern void (*_sysfatal)(char*, va_list);
+extern Jmp *(*_notejmpbuf)(void);
 
 static void
 mainlauncher(void *arg)
@@ -24,58 +22,24 @@
 	Mainarg *a;
 
 	a = arg;
-	_threadmaininit();
+	_kmaininit();
 	threadmain(a->argc, a->argv);
 	threadexits("threadmain");
 }
 
-static void
-passer(void *x, char *msg)
-{
-	USED(x);
-	Waitmsg *w;
-
-	if(strcmp(msg, "sys: usr2") == 0)
-		_exit(0);	/* daemonize */
-	else if(strcmp(msg, "sys: child") == 0){
-		w = wait();
-		if(w == nil)
-			_exit(1);
-		_exit(atoi(w->msg));
-	}else
-		postnote(PNPROC, passtomainpid, msg);
-}
-
 int
 main(int argc, char **argv)
 {
-	int pid;
 	Mainarg a;
 	Proc *p;
-	sigset_t mask;
 
 	/*
-	 * Do daemonize hack here.
+	 * In pthreads, threadmain is actually run in a subprocess,
+	 * so that the main process can exit (if threaddaemonize is called).
+	 * The main process relays notes to the subprocess.
+	 * _Threadbackgroundsetup will return only in the subprocess.
 	 */
-	if(_callsthreaddaemonize){
-		passtomainpid = getpid();
-		switch(pid = fork()){
-		case -1:
-			sysfatal("fork: %r");
-
-		case 0:
-			/* continue executing */
-			_threadmainpid = getppid();
-			break;
-
-		default:
-			/* wait for signal USR2 */
-			notify(passer);
-			for(;;)
-				pause();
-			_exit(0);
-		}
-	}
+	_threadbackgroundinit();
 
 	/*
 	 * Instruct QLock et al. to use our scheduling functions
@@ -85,16 +49,17 @@
 
 	/*
 	 * Install our own _threadsysfatal which takes down
-	 * the whole conglomeration of procs.
+	 * the whole confederation of procs.
 	 */
 	_sysfatal = _threadsysfatal;
 
 	/*
-	 * XXX Install our own jump handler.
+	 * Install our own jump handler.
 	 */
+	_notejmpbuf = _threadgetjmp;
 
 	/*
-	 * Install our own signal handlers.
+	 * Install our own signal handler.
 	 */
 	notify(_threadnote);
 
@@ -119,3 +84,15 @@
 _threadlinkmain(void)
 {
 }
+
+Jmp*
+_threadgetjmp(void)
+{
+	static Jmp j;
+	Proc *p;
+
+	p = _threadgetproc();
+	if(p == nil)
+		return &j;
+	return &p->sigjmp;
+}
diff --git a/src/libthread/mkfile b/src/libthread/mkfile
index e51d195..6492bb9 100644
--- a/src/libthread/mkfile
+++ b/src/libthread/mkfile
@@ -1,15 +1,12 @@
 <$PLAN9/src/mkhdr
 
 LIB=libthread.a
-THREAD=`sh ./thread.sh`
+SYSOFILES=`sh ./sysofiles.sh`
 OFILES=\
-	$OBJTYPE.$O\
-	$THREAD.$O\
-	asm-$SYSNAME-$OBJTYPE.$O\
+	$SYSOFILES\
 	channel.$O\
 	chanprint.$O\
 	create.$O\
-	daemon.$O\
 	debug.$O\
 	exec-unix.$O\
 	exit.$O\
@@ -29,10 +26,10 @@
 	main.$O\
 	memset.$O\
 	memsetd.$O\
-	note.$O\
 	read9pmsg.$O\
 	ref.$O\
 	sched.$O\
+	setproc.$O\
 	sleep.$O\
 
 HFILES=\
@@ -57,6 +54,9 @@
 trend: trend.$O $PLAN9/lib/$LIB
 	$LD -o trend trend.$O $LDFLAGS -lthread -l9
 
+tsignal: tsignal.$O $PLAN9/lib/$LIB
+	$LD -o tsignal tsignal.$O $LDFLAGS -lthread -l9
+
 CLEANFILES=$CLEANFILES tprimes texec
 
 asm-Linux-ppc.$O: asm-Linux-386.s
diff --git a/src/libthread/pthread.c b/src/libthread/pthread.c
index 8d661c1..83d8b02 100644
--- a/src/libthread/pthread.c
+++ b/src/libthread/pthread.c
@@ -2,53 +2,36 @@
 #include <errno.h>
 #include "threadimpl.h"
 
-static int multi;
-static Proc *theproc;
+/*
+ * Basic kernel thread management.
+ */
 static pthread_key_t key;
 
-/*
- * Called before we go multiprocess.
- */
 void
-_threadmultiproc(void)
+_kthreadinit(void)
 {
-	if(multi == 0){
-		multi = 1;
-		pthread_key_create(&key, 0);
-		_threadsetproc(theproc);
-	}
+	pthread_key_create(&key, 0);
 }
 
-/*
- * Set the proc for the current pthread.
- */
 void
-_threadsetproc(Proc *p)
+_kthreadsetproc(Proc *p)
 {
-	if(!multi){
-		theproc = p;
-		return;
-	}
+	sigset_t all;
+
+	p->pthreadid = pthread_self();
+	sigfillset(&all);
+	pthread_sigmask(SIG_SETMASK, &all, nil);
 	pthread_setspecific(key, p);
 }
 
-/* 
- * Get the proc for the current pthread.
- */
 Proc*
-_threadgetproc(void)
+_kthreadgetproc(void)
 {
-	if(!multi)
-		return theproc;
-
 	return pthread_getspecific(key);
 }
 
-/*
- * Called to start a new proc.
- */
 void
-_threadstartproc(Proc *p)
+_kthreadstartproc(Proc *p)
 {
 	Proc *np;
 	pthread_t tid;
@@ -63,69 +46,43 @@
 	np->pthreadid = tid;
 }
 
-/*
- * Called to associate p with the current pthread.
- */
 void
-_threadinitproc(Proc *p)
-{
-	p->pthreadid = pthread_self();
-	_threadsetproc(p);
-}
-
-/*
- * Called to exit the current pthread.
- */
-void
-_threadexitproc(char *exitstr)
+_kthreadexitproc(char *exitstr)
 {
 	_threaddebug(DBGSCHED, "_pthreadexit");
 	pthread_exit(nil);
 }
 
-/*
- * Called to exit all pthreads.
- */
 void
-_threadexitallproc(char *exitstr)
+_kthreadexitallproc(char *exitstr)
 {
 	_threaddebug(DBGSCHED, "_threadexitallproc");
 	exits(exitstr);
 }
 
 /*
- * Called to poll for any kids of this pthread.
- * Wait messages aren't restricted to a particular
- * pthread, so we have a separate proc responsible
- * for them.  So this is a no-op.
+ * Exec.  Pthreads does the hard work of making it possible
+ * for any thread to do the waiting, so this is pretty easy.
+ * We create a separate proc whose job is to wait for children
+ * and deliver wait messages.
  */
-void
-_threadwaitkids(Proc *p)
-{
-}
+static Channel *_threadexecwaitchan;
 
-/*
- * Separate process to wait for child messages.
- * Also runs signal handlers.
- */
-static Channel *_threadexecchan;
 static void
 _threadwaitproc(void *v)
 {
 	Channel *c;
 	Waitmsg *w;
-	sigset_t none;
 
-	sigemptyset(&none);
-	pthread_sigmask(SIG_SETMASK, &none, 0);
+	_threadinternalproc();
 
 	USED(v);
 	
 	for(;;){
 		w = wait();
 		if(w == nil){
-			if(errno == ECHILD)
-				recvul(_threadexecchan);
+			if(errno == ECHILD)	/* wait for more */
+				recvul(_threadexecwaitchan);
 			continue;
 		}
 		if((c = _threadwaitchan) != nil)
@@ -133,43 +90,182 @@
 		else
 			free(w);
 	}
-fprint(2, "_threadwaitproc exits\n");
+	fprint(2, "_threadwaitproc exits\n");	/* not reached */
 }
 
+
 /* 
- * Called before the first exec.
+ * Call _threadexec in the right conditions.
  */
-void
-_threadfirstexec(void)
+int
+_kthreadexec(Channel *c, int fd[3], char *prog, char *args[], int freeargs)
 {
+	static Lock lk;
+	int rv;
+
+	if(!_threadexecwaitchan){
+		lock(&lk);
+		if(!_threadexecwaitchan){
+			_threadexecwaitchan = chancreate(sizeof(ulong), 1);
+			proccreate(_threadwaitproc, nil, 32*1024);
+		}
+		unlock(&lk);
+	}
+	rv = _threadexec(c, fd, prog, args, freeargs);
+	nbsendul(_threadexecwaitchan, 1);
+	return rv;
 }
 
 /*
- * Called from mainlauncher before threadmain.
+ * Some threaded applications want to run in the background.
+ * Calling fork() and exiting in the parent will result in a child
+ * with a single pthread (if we are using pthreads), and will screw
+ * up our internal process info if we are using clone/rfork.
+ * Instead, apps should call threadbackground(), which takes
+ * care of this.
+ * 
+ * _threadbackgroundinit is called from main.
  */
-void
-_threadmaininit(void)
-{
-	_threadexecchan = chancreate(sizeof(ulong), 1);
-	proccreate(_threadwaitproc, nil, 32*1024);
 
-	/*
-	 * Sleazy: decrement threadnprocs so that 
-	 * the existence of the _threadwaitproc proc
-	 * doesn't keep us from exiting.
-	 */
-	lock(&_threadpq.lock);
-	--_threadnprocs;
-	/* print("change %d -> %d\n", _threadnprocs+1, _threadnprocs); */
-	unlock(&_threadpq.lock);
+static int mainpid, passerpid;
+
+static void
+passer(void *x, char *msg)
+{
+	Waitmsg *w;
+
+	USED(x);
+	if(strcmp(msg, "sys: usr2") == 0)
+		_exit(0);	/* daemonize */
+	else if(strcmp(msg, "sys: child") == 0){
+		/* child exited => so should we */
+		w = wait();
+		if(w == nil)
+			_exit(1);
+		_exit(atoi(w->msg));
+	}else
+		postnote(PNGROUP, mainpid, msg);
+}
+
+void
+_threadbackgroundinit(void)
+{
+	int pid;
+	sigset_t mask;
+
+	sigfillset(&mask);
+	pthread_sigmask(SIG_BLOCK, &mask, 0);
+
+return;
+
+	passerpid = getpid();
+	switch(pid = fork()){
+	case -1:
+		sysfatal("fork: %r");
+
+	case 0:
+		rfork(RFNOTEG);
+		return;
+
+	default:
+		break;
+	}
+
+	mainpid = pid;
+	notify(passer);
+	notifyon("sys: child");
+	notifyon("sys: usr2");	/* should already be on */
+	for(;;)
+		pause();
+	_exit(0);
+}
+
+void
+threadbackground(void)
+{
+	if(passerpid <= 1)
+		return;
+	postnote(PNPROC, passerpid, "sys: usr2");
 }
 
 /*
- * Called after forking the exec child.
+ * Notes.
  */
-void
-_threadafterexec(void)
+Channel *_threadnotechan;
+static ulong sigs;
+static Lock _threadnotelk;
+static void _threadnoteproc(void*);
+extern int _p9strsig(char*);
+extern char *_p9sigstr(int);
+
+Channel*
+threadnotechan(void)
 {
-	nbsendul(_threadexecchan, 1);
+	if(_threadnotechan == nil){
+		lock(&_threadnotelk);
+		if(_threadnotechan == nil){
+			_threadnotechan = chancreate(sizeof(char*), 1);
+			proccreate(_threadnoteproc, nil, 32*1024);
+		}
+		unlock(&_threadnotelk);
+	}
+	return _threadnotechan;
 }
 
+void
+_threadnote(void *x, char *msg)
+{
+	USED(x);
+
+	if(_threadexitsallstatus)
+		_kthreadexitproc(_threadexitsallstatus);
+
+	if(strcmp(msg, "sys: usr2") == 0)
+		noted(NCONT);
+
+	if(_threadnotechan == nil)
+		noted(NDFLT);
+
+	sigs |= 1<<_p9strsig(msg);
+	noted(NCONT);
+}
+
+void
+_threadnoteproc(void *x)
+{
+	int i;
+	sigset_t none;
+	Channel *c;
+
+	_threadinternalproc();
+	sigemptyset(&none);
+	pthread_sigmask(SIG_SETMASK, &none, 0);
+
+	c = _threadnotechan;
+	for(;;){
+		if(sigs == 0)
+			pause();
+		for(i=0; i<32; i++){
+			if((sigs&(1<<i)) == 0)
+				continue;
+			sigs &= ~(1<<i);
+			if(i == 0)
+				continue;
+			sendp(c, _p9sigstr(i));
+		}
+	}
+}
+
+void
+_threadschednote(void)
+{
+}
+
+void
+_kmaininit(void)
+{
+	sigset_t all;
+
+	sigfillset(&all);
+	pthread_sigmask(SIG_SETMASK, &all, 0);
+}
diff --git a/src/libthread/sched.c b/src/libthread/sched.c
index 7e43019..ac982da 100644
--- a/src/libthread/sched.c
+++ b/src/libthread/sched.c
@@ -18,13 +18,12 @@
 	p = arg;
 
 	_threadlinkmain();
-	_threadinitproc(p);
+	_threadsetproc(p);
 
 	for(;;){
 		/* 
 		 * Clean up zombie children.
 		 */
-		_threadwaitkids(p);
 
 		/*
 		 * Find next thread to run.
@@ -154,6 +153,7 @@
 	if(p->nthreads==0 || (p->nthreads==1 && p->idle))
 		return nil;
 
+	_threadschednote();
 	lock(&p->readylock);
 	q = &p->ready;
 	if(q->head == nil){
@@ -180,7 +180,10 @@
 		 */
 		q->asleep = 1;
 		p->rend.l = &p->readylock;
-		_procsleep(&p->rend);
+		while(q->asleep){
+			_procsleep(&p->rend);
+			_threadschednote();
+		}
 
 		/*
 		 * Maybe we were awakened to exit?
@@ -284,6 +287,25 @@
 	unlock(&p->readylock);
 }
 
+/*
+ * Mark proc as internal so that if all but internal procs exit, we exit.
+ */
+void
+_threadinternalproc(void)
+{
+	Proc *p;
+
+	p = _threadgetproc();
+	if(p->internal)
+		return;
+	lock(&_threadpq.lock);
+	if(p->internal == 0){
+		p->internal = 1;
+		--_threadnprocs;
+	}
+	unlock(&_threadpq.lock);
+}
+
 static void
 schedexit(Proc *p)
 {
@@ -301,7 +323,10 @@
 			break;
 		}
 	}
-	n = --_threadnprocs;
+	if(p->internal)
+		n = _threadnprocs;
+	else
+		n = --_threadnprocs;
 	unlock(&_threadpq.lock);
 
 	strncpy(ex, p->exitstr, sizeof ex);
@@ -309,10 +334,10 @@
 	free(p);
 	if(n == 0){
 		_threaddebug(DBGSCHED, "procexit; no more procs");
-		_threadexitallproc(ex);
+		_kthreadexitallproc(ex);
 	}else{
 		_threaddebug(DBGSCHED, "procexit");
-		_threadexitproc(ex);
+		_kthreadexitproc(ex);
 	}
 }
 
diff --git a/src/libthread/sleep.c b/src/libthread/sleep.c
index d6c4dac..4b0d82a 100644
--- a/src/libthread/sleep.c
+++ b/src/libthread/sleep.c
@@ -36,3 +36,4 @@
 	_threadready(t);
 	unlock(&t->proc->lock);
 }
+
diff --git a/src/libthread/thread.sh b/src/libthread/thread.sh
index e3984b7..818b509 100644
--- a/src/libthread/thread.sh
+++ b/src/libthread/thread.sh
@@ -2,13 +2,13 @@
 
 if [ `uname` = Linux ]
 then
-	case "`uname | awk '{print $3}'`" in
-	*)
-		echo Linux-clone
-		;;
+	case `uname -r` in
 	2.[6789]*)
 		echo pthread
 		;;
+	*)
+		echo Linux-clone
+		;;
 	esac
 else
 	echo pthread
diff --git a/src/libthread/threadimpl.h b/src/libthread/threadimpl.h
index 8d7a7a7..0ad4568 100644
--- a/src/libthread/threadimpl.h
+++ b/src/libthread/threadimpl.h
@@ -28,6 +28,14 @@
 typedef struct Tqueue	Tqueue;
 typedef struct Pqueue	Pqueue;
 typedef struct Execargs	Execargs;
+typedef struct Jmp Jmp;
+
+/* sync with ../lib9/notify.c */
+struct Jmp
+{
+	p9jmp_buf b;
+};
+
 
 typedef enum
 {
@@ -126,6 +134,7 @@
 	Proc		*newproc;	/* fork argument */
 	char		exitstr[ERRMAX];	/* exit status */
 
+	int		internal;
 	int		rforkflag;
 	int		nthreads;
 	Tqueue	threads;		/* All threads of this proc */
@@ -138,6 +147,7 @@
 	uint		nextID;		/* ID of most recently created thread */
 	Proc		*next;		/* linked list of Procs */
 
+	Jmp		sigjmp;		/* for notify implementation */
 
 	void		(*schedfn)(Proc*);	/* function to call in scheduler */
 
@@ -161,8 +171,6 @@
 void		_swaplabel(Label*, Label*);
 Proc*	_newproc(void);
 int		_newthread(Proc*, void(*)(void*), void*, uint, char*, int);
-int		_procsplhi(void);
-void		_procsplx(int);
 int		_sched(void);
 int		_schedexec(Execargs*);
 void		_schedexecwait(void);
@@ -178,14 +186,14 @@
 Proc*	_threadgetproc(void);
 extern void	_threadmultiproc(void);
 Proc*	_threaddelproc(void);
-void		_threadinitproc(Proc*);
-void		_threadwaitkids(Proc*);
+void		_kthreadinitproc(Proc*);
 void		_threadsetproc(Proc*);
 void		_threadinitstack(Thread*, void(*)(void*), void*);
 void		_threadlinkmain(void);
 void*	_threadmalloc(long, int);
 void		_threadnote(void*, char*);
 void		_threadready(Thread*);
+void		_threadschednote(void);
 void		_threadsetidle(int);
 void		_threadsleep(_Procrend*);
 void		_threadwakeup(_Procrend*);
@@ -195,12 +203,18 @@
 void		_xinc(long*);
 void		_threadremove(Proc*, Thread*);
 void		threadstatus(void);
-void		_threadstartproc(Proc*);
-void		_threadexitproc(char*);
-void		_threadexitallproc(char*);
 void		_threadefork(int[3], int[2], char*, char**);
+Jmp*		_threadgetjmp(void);
+void		_kthreadinit(void);
+void		_kthreadsetproc(Proc*);
+Proc*	_kthreadgetproc(void);
+void		_kthreadstartproc(Proc*);
+void		_kthreadexitproc(char*);
+void		_kthreadexitallproc(char*);
+void		_threadinternalproc(void);
+void		_threadbackgroundinit(void);
+void		_kmaininit(void);
 
-extern int			_threadmainpid;
 extern int			_threadnprocs;
 extern int			_threaddebuglevel;
 extern char*		_threadexitsallstatus;
@@ -222,8 +236,6 @@
 extern void _procdelthread(Proc*, Thread*);
 extern void _procaddthread(Proc*, Thread*);
 
-extern void _threadafterexec(void);
 extern void _threadmaininit(void);
-extern void _threadfirstexec(void);
 extern int _threadexec(Channel*, int[3], char*, char*[], int);
-extern int _callthreadexec(Channel*, int[3], char*, char*[], int);
+extern int _kthreadexec(Channel*, int[3], char*, char*[], int);