kernel: Turn the delay before mounting root into a tunable.

Submitted-by:  Francis Gudin <fgudin@nerim.net>
Dragonfly-bug: <http://bugs.dragonflybsd.org/issues/2373>

diff --git a/sys/boot/common/loader.8 b/sys/boot/common/loader.8
index f20b656..2d691f6 100644 (file)
--- a/sys/boot/common/loader.8
+++ b/sys/boot/common/loader.8
@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD: src/sys/boot/common/loader.8,v 1.57 2003/06/29 20:57:55 brueffer Exp $
 .\"
-.Dd October 16, 2011
+.Dd August 27, 2012
 .Dt LOADER 8
 .Os
 .Sh NAME
@@ -723,6 +723,9 @@ Overrides the compile-time set value of
 .Va TCBHASHSIZE
 or the preset default of 512.
 Must be a power of 2.
+.It Va vfs.root.wakedelay
+Specify an additional delay (default is 2 seconds if unspecified)
+before trying to mount root.
 .It Va vfs.root.mountfrom
 Specify root file system.
 A semicolon separated list of file systems to try

diff --git a/sys/boot/dloader/loader.conf b/sys/boot/dloader/loader.conf
index df3aead..d8dfb85 100644 (file)
--- a/sys/boot/dloader/loader.conf
+++ b/sys/boot/dloader/loader.conf
@@ -94,6 +94,8 @@ bitmap_type="splash_image_data" # and place it on the module_path
 #kern.ipc.nmbufs=""            # Set the maximum number of mbufs
 #kern.vm.kmem.size=""          # Sets the size of kernel memory (bytes)
 #net.inet.tcp.tcbhashsize=""   # Set the value of TCBHASHSIZE
+#vfs.root.wakedelay=""         # Delay in seconds before trying to mount the
+                               # root
 #vfs.root.mountfrom=""         # Specify root partition in a way the
                                # kernel understands. You can specify a
                                # semicolon separated device list which will

diff --git a/sys/kern/vfs_conf.c b/sys/kern/vfs_conf.c
index 2795314..b38bc8b 100644 (file)
--- a/sys/kern/vfs_conf.c
+++ b/sys/kern/vfs_conf.c
@@ -102,7 +102,10 @@ char               *rootdevnames[2] = {NULL, NULL};
 static int     setrootbyname(char *name);
 
 SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL);
-       
+
+static int wakedelay = 2;      /* delay before mounting root in seconds */
+TUNABLE_INT("vfs.root.wakedelay", &wakedelay);
+
 /*
  * Find and mount the root filesystem
  */
@@ -121,12 +124,12 @@ vfs_mountroot(void *junk)
         * Messages can fly around here so get good synchronization
         * coverage.
         *
-        * XXX - Delay an additional 2 seconds to help drivers which pickup
+        * XXX - Delay some more (default: 2s) to help drivers which pickup
         *       devices asynchronously and are not caught by CAM's initial
         *       probe.
         */
        sync_devs();
-       tsleep(&dummy, 0, "syncer", hz*2);
+       tsleep(&dummy, 0, "syncer", hz * wakedelay);
 
 
        /*