add thread names to vmd(8)

[Dave Voutila]

Now that guenther@ landed thread names, this should help users
understand vmd host cpu utilization better as it lets us distinguish
between the libevent thread and the vcpu thread.

Example ps output:

$ ps -AHf | grep vmd
30584  502984 p2  S+p      0:00.76 | |-- obj/vmd -d
46975  512305 ??  Sc       0:00.01 | | |-- vmd: priv (vmd)
39911  487276 ??  Spc      0:00.76 | | |-- vmd: control (vmd)
58206  418514 ??  Spc      0:00.01 | | |-- vmd: vmm (vmd)
43525  215149 ??  Sp       0:00.00 | | | |-- vmd: openbsd (vmd/event)
43525  316255 ??  Rp/5     0:00.77 | | | |-- vmd: openbsd (vmd/vcpu-0)
43525  270611 ??  Sp       0:00.00 | | | `-- vmd: openbsd (vmd)
43206  562455 ??  Spc      0:00.01 | | |-- vmd: agentx (vmd)
70005  431096 p3  R+p/9    0:00.00 | |-- grep vmd

ok?

-dv


diff refs/heads/master refs/heads/vmd-threadnames
commit - bfce157fda90a812e1a99aa179a4c42f12ebfa24
commit + c68a6ec15bd158fb7bc769fd5beefaace3d26d5c
blob - f2852411550a07d25bf46f1e0de5ed317fb8c108
blob + 0bb3fd3f875ee4af1c92cd1f508bb09f3b8c865e
--- usr.sbin/vmd/vm.c
+++ usr.sbin/vmd/vm.c
@@ -16,7 +16,7 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */

-#include <sys/param.h> /* PAGE_SIZE */
+#include <sys/param.h> /* PAGE_SIZE, MAXCOMLEN */
 #include <sys/types.h>
 #include <sys/ioctl.h>
 #include <sys/queue.h>
@@ -46,6 +46,7 @@
 #include <limits.h>
 #include <poll.h>
 #include <pthread.h>
+#include <pthread_np.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -1211,6 +1212,7 @@ run_vm(int child_cdrom, int child_disks[][VM_MAX_BASE_
        size_t i;
        int ret;
        pthread_t *tid, evtid;
+       char tname[MAXCOMLEN + 1];
        struct vm_run_params **vrp;
        void *exit_status;

@@ -1353,6 +1355,10 @@ run_vm(int child_cdrom, int child_disks[][VM_MAX_BASE_
                            __func__, i);
                        return (ret);
                }
+
+               memset(tname, 0, sizeof(tname));
+               snprintf(tname, sizeof(tname), "vcpu-%zu", i);
+               pthread_set_name_np(tid[i], tname);
        }

        log_debug("%s: waiting on events for VM %s", __func__, vcp->vcp_name);
@@ -1362,6 +1368,7 @@ run_vm(int child_cdrom, int child_disks[][VM_MAX_BASE_
                log_warn("%s: could not create event thread", __func__);
                return (ret);
        }
+       pthread_set_name_np(evtid, "event");

        for (;;) {
                ret = pthread_cond_wait(&threadcond, &threadmutex);