clean up the production of /dev/swap and add new allocb stats.

Reference: /n/atom/patch/applied/devswapfix
Date: Thu Jan 16 23:50:59 CET 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/port/qmalloc.c	Thu Jan 16 23:50:42 2014
+++ /sys/src/nix/port/qmalloc.c	Thu Jan 16 23:50:42 2014
@@ -379,8 +379,8 @@
 	return (nunits-1) * sizeof(Header);
 }
 
-static void
-mallocreadfmt(char* s, char* e)
+char*
+mallocstats(char* s, char* e)
 {
 	char *p;
 	Header *q;
@@ -443,6 +443,7 @@
 		p = seprint(p, e, "%s %ud\n", qstatstr[i], qstats[i]);
 	}
 	MUNLOCK;
+	return p;
 }
 
 long
@@ -455,7 +456,7 @@
 		free(alloc);
 		nexterror();
 	}
-	mallocreadfmt(alloc, alloc+16*READSTR);
+	mallocstats(alloc, alloc+16*READSTR);
 	n = readstr(offset, a, n, alloc);
 	poperror();
 	free(alloc);
--- /sys/src/nix/port/portfns.h	Thu Jan 16 23:50:43 2014
+++ /sys/src/nix/port/portfns.h	Thu Jan 16 23:50:43 2014
@@ -1,4 +1,3 @@
-void		_assert(char*);
 void		accounttime(void);
 void		addbootfile(char*, uchar*, ulong);
 Timer*		addclock0link(void (*)(void), int);
@@ -12,8 +11,10 @@
 int		ainc(int*);
 void		alarmkproc(void*);
 Block*		allocb(int);
+char*		allocbstats(char*, char*);
 int		anyhigher(void);
 int		anyready(void);
+void		_assert(char*);
 Image*		attachimage(int, Chan*, int, uintptr, uintptr);
 Page*		auxpage(usize);
 Block*		bl2mem(uchar*, Block*, int);
@@ -163,7 +164,7 @@
 Cmdtab*		lookupcmd(Cmdbuf*, Cmdtab*, int);
 int		machcolor(Mach*);
 void		mallocinit(void);
-long		mallocreadsummary(Chan*, void*, long, long);
+char*		mallocstats(char*, char*);
 void		mallocsummary(void);
 Block*		mem2bl(uchar*, int);
 void		(*mfcinit)(void);
--- /sys/src/nix/port/devcons.c	Thu Jan 16 23:50:43 2014
+++ /sys/src/nix/port/devcons.c	Thu Jan 16 23:50:43 2014
@@ -411,7 +411,7 @@
 	if(ainc(&panicking)>1){
 		if(m->machno == pmno)
 			archreset();
-		ndnr();
+		exit(1);
 	}
 	pmno = m->machno;
 	synccons();
@@ -483,9 +483,9 @@
 static void
 echo(char *buf, int n)
 {
+	char *e, *p;
 	Mpl pl;
 	static int ctrlt, pid;
-	char *e, *p;
 
 	if(n == 0)
 		return;
@@ -987,25 +987,26 @@
 			nexterror();
 		}
 		n = readstr(offset, buf, n, b);
-		free(b);
 		poperror();
+		free(b);
 		return n;
 
 	case Qswap:
-		tmp[0] = 0;
-		s = seprintpagestats(tmp, tmp + sizeof tmp);
-		s = seprintphysstats(s, tmp + sizeof tmp);
-		b = buf;
-		l = s - tmp;
-		i = readstr(offset, b, l, tmp);
-		b += i;
-		n -= i;
-		if(offset > l)
-			offset -= l;
-		else
-			offset = 0;
-
-		return i + mallocreadsummary(c, b, n, offset);
+		s = b = smalloc(READSTR);
+		e = b + READSTR;
+		s = seprintpagestats(s, e);
+		s = seprintphysstats(s, e);
+		s = allocbstats(s, e);
+		s = mallocstats(s, e);
+		USED(s);
+		if(waserror()){
+			free(b);
+			nexterror();
+		}
+		n = readstr(offset, buf, n, b);
+		poperror();
+		free(b);
+		return n;
 
 	case Qsysname:
 		if(sysname == nil)