svn commit: r335458 - head/sys/kern

[Kyle Evans]

Author: kevans
Date: Wed Jun 20 19:23:56 2018
New Revision: 335458
URL: https://svnweb.freebsd.org/changeset/base/335458

Log:
  Add debug.verbose_sysinit tunable for VERBOSE_SYSINIT
  
  VERBOSE_SYSINIT is currently an all-or-nothing option. debug.verbose_sysinit
  adds an option to have the code compiled in but quiet by default so that
  getting this information from a device in the field doesn't necessarily
  require distributing a recompiled kernel.
  
  Its default is VERBOSE_SYSINIT's value as defined in the kernconf. As such,
  the default behavior for simply omitting or including this option is
  unchanged.
  
  MFC after:	1 week

Modified:
  head/sys/kern/init_main.c

Modified: head/sys/kern/init_main.c
==============================================================================
--- head/sys/kern/init_main.c	Wed Jun 20 19:22:33 2018	(r335457)
+++ head/sys/kern/init_main.c	Wed Jun 20 19:23:56 2018	(r335458)
@@ -119,6 +119,18 @@ int	bootverbose = BOOTVERBOSE;
 SYSCTL_INT(_debug, OID_AUTO, bootverbose, CTLFLAG_RW, &bootverbose, 0,
 	"Control the output of verbose kernel messages");
 
+#ifdef VERBOSE_SYSINIT
+/*
+ * We'll use the defined value of VERBOSE_SYSINIT from the kernel config to
+ * dictate the default VERBOSE_SYSINIT behavior.  Significant values for this
+ * option and associated tunable are:
+ * - 0, 'compiled in but silent by default'
+ * - 1, 'compiled in but verbose by default' (default)
+ */
+int	verbose_sysinit = VERBOSE_SYSINIT;
+TUNABLE_INT("debug.verbose_sysinit", &verbose_sysinit);
+#endif
+
 #ifdef INVARIANTS
 FEATURE(invariants, "Kernel compiled with INVARIANTS, may affect performance");
 #endif
@@ -268,7 +280,7 @@ restart:
 			continue;
 
 #if defined(VERBOSE_SYSINIT)
-		if ((*sipp)->subsystem > last) {
+		if ((*sipp)->subsystem > last && verbose_sysinit != 0) {
 			verbose = 1;
 			last = (*sipp)->subsystem;
 			printf("subsystem %x\n", last);