powerd: Wait hw.acpi.cpu.px_dom* sysctl to be created by kernel

Since hw.acpi.cpu.px_dom* creation is queued into ACPI taskqueue
and ACPI taskqueue is shared across various ACPI modules, any delay
in other modules may cause hw.acpi.cpu.px_dom* to be created at
quite a later time (e.g. cmbat module's task could take quite a lot
of time).

diff --git a/usr.sbin/powerd/powerd.c b/usr.sbin/powerd/powerd.c
index d9a339b..214138c 100644 (file)
--- a/usr.sbin/powerd/powerd.c
+++ b/usr.sbin/powerd/powerd.c
@@ -86,20 +86,8 @@ main(int ac, char **av)
        av += optind;
 
        /*
-        * Prime delta cputime calculation, make sure at least dom0 exists,
-        * and make sure powerd is not already running.
+        * Make sure powerd is not already running.
         */
-       getcputime();
-       savg = 0.0;
-
-       setupdominfo();
-       if (DomBeg >= DomEnd) {
-               fprintf(stderr, "hw.acpi.cpu.px_dom* sysctl not available\n");
-               exit(1);
-       }
-       DomLimit = DomEnd;
-       CpuLimit = NCpus;
-
        PowerFd = open("/var/run/powerd.pid", O_CREAT|O_RDWR, 0644);
        if (PowerFd < 0) {
                fprintf(stderr,
@@ -127,6 +115,34 @@ main(int ac, char **av)
        }
 
        /*
+        * Wait hw.acpi.cpu.px_dom* sysctl to be created by kernel
+        *
+        * Since hw.acpi.cpu.px_dom* creation is queued into ACPI
+        * taskqueue and ACPI taskqueue is shared across various
+        * ACPI modules, any delay in other modules may cause
+        * hw.acpi.cpu.px_dom* to be created at quite a later time
+        * (e.g. cmbat module's task could take quite a lot of time).
+        */
+       for (;;) {
+               /*
+                * Prime delta cputime calculation, make sure at least
+                * dom0 exists.
+                */
+               getcputime();
+               savg = 0.0;
+
+               setupdominfo();
+               if (DomBeg >= DomEnd) {
+                       sleep(1);
+                       continue;
+               }
+
+               DomLimit = DomEnd;
+               CpuLimit = NCpus;
+               break;
+       }
+
+       /*
         * Monitoring loop
         *
         * Calculate nstate, the number of cpus we wish to run at max