--- startpar.c	2008-07-18 13:25:50.000000000 +0200
+++ startpar.c	2009-02-12 14:49:10.987760000 +0100
@@ -29,6 +29,8 @@
 #include <sys/select.h>
 #include <sys/time.h>
 #include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/un.h>
 #include <sys/sysinfo.h>
 #include <sys/stat.h>
 #include <time.h>
@@ -64,6 +66,8 @@
 static char *run_mode = NULL;
 static struct makenode **nodevec;
 
+static enum { Unknown, Preload, NoPreload } ispreload = Unknown;
+
 #define PBUF_SIZE	8192
 struct prg {
   char *name;
@@ -248,6 +252,10 @@
   if (read_proc(&prcs_run, &prcs_blked))
     return par;
 
+  /* if we have preload running, we expect I/O not to be a problem */
+  if (ispreload == Preload)
+    prcs_blked = 0;
+
   newpar  = (par*numcpu) - prcs_run + 1; 	/* +1 for startpar its self */
   newpar -= (int)(((double)prcs_blked)*iorate);	/* I/O load reduction */
 
@@ -271,6 +279,8 @@
   return checksystem(par, start, false);
 }
 
+#define SOCK_PATH "/dev/shm/preload_sock"
+
 void run(struct prg *p)
 {
   char *m = 0;
@@ -341,6 +351,40 @@
 
   closeall();
 
+  if (!strcmp(arg, "start")) 
+    { 
+      int s, t, len;
+      struct sockaddr_un remote;
+      char str[100];
+
+      s = socket(AF_UNIX, SOCK_STREAM, 0);
+      if (s != -1) 
+	{
+	  memset(&remote, 0, sizeof(struct sockaddr_un));
+	  remote.sun_family = AF_UNIX;
+	  strcpy(remote.sun_path, SOCK_PATH);
+	  len = strlen(remote.sun_path) + sizeof(remote.sun_family);
+
+	  t = connect(s, (struct sockaddr *)&remote, len);
+	  if (t != -1) 
+	    {
+	      ispreload = Preload;
+	      send(s, p->name, strlen(p->name), 0);
+	      recv(s, str, 100, 0);
+	    } 
+	  else if ( ispreload == Unknown) 
+	    {
+	      /*
+	       * if we connected to preload once, we know it ran.
+	       * In case we can't connect to it later, it means it did
+	       * its job and we can guess I/O is no longer a problem. 
+	       */
+	      ispreload = NoPreload;
+	    }
+	  close(s);
+	}
+    }
+
   if (run_mode)
     {
       char path[128];