turn threads info into an optional flag

[Paul Irofti]

This is on top of the former ps(1) & friends usage diff.

Turns the threads info into an optional flag. Okay?

The ps(1) and top(1) bits will go in as well afterwards.

Index: sys/sysctl.h
===================================================================
RCS file: /cvs/src/sys/sys/sysctl.h,v
retrieving revision 1.124
diff -u -p -r1.124 sysctl.h
--- sys/sysctl.h        12 Apr 2012 14:59:18 -0000      1.124
+++ sys/sysctl.h        13 Apr 2012 18:13:49 -0000
@@ -288,6 +288,7 @@ struct ctlname {
 #define        KERN_PROC_UID           5       /* by effective uid */
 #define        KERN_PROC_RUID          6       /* by real uid */
 #define        KERN_PROC_KTHREAD       7       /* also return kernel threads */
+#define        KERN_PROC_THREADS       0x80000000      /* also return normal 
threads */
 
 /*
  * KERN_SYSVIPC_INFO subtypes
Index: kern/kern_sysctl.c
===================================================================
RCS file: /cvs/src/sys/kern/kern_sysctl.c,v
retrieving revision 1.220
diff -u -p -r1.220 kern_sysctl.c
--- kern/kern_sysctl.c  12 Apr 2012 14:59:19 -0000      1.220
+++ kern/kern_sysctl.c  13 Apr 2012 18:13:50 -0000
@@ -1373,6 +1373,7 @@ sysctl_doproc(int *name, u_int namelen, 
        char *dp;
        int arg, buflen, doingzomb, elem_size, elem_count;
        int error, needed, op;
+       int dothreads = 0;
 
        dp = where;
        buflen = where != NULL ? *sizep : 0;
@@ -1386,6 +1387,9 @@ sysctl_doproc(int *name, u_int namelen, 
        elem_size = name[2];
        elem_count = name[3];
 
+       dothreads = op & KERN_PROC_THREADS;
+       op &= ~KERN_PROC_THREADS;
+
        if (where != NULL)
                kproc = malloc(sizeof(*kproc), M_TEMP, M_WAITOK);
 
@@ -1470,6 +1474,10 @@ again:
                        }
                        needed += elem_size;
                }
+               /* Skip the second entry if not required by op */
+               if (!dothreads)
+                       continue;
+
                if (buflen >= elem_size && elem_count > 0) {
                        fill_kproc(p, kproc, 1);
                        error = copyout(kproc, dp, elem_size);