Revert r267961, r267973:

These changes prevent sysctl(8) from returning proper output,
such as:

 1) no output from sysctl(8)
 2) erroneously returning ENOMEM with tools like truss(1)
    or uname(1)
 truss: can not get etype: Cannot allocate memory

9 files changed, 17 insertions, 8 deletions

diff --git a/sys/i386/acpica/acpi_machdep.c b/sys/i386/acpica/acpi_machdep.c
index 049354b..a244e73 100644
--- a/sys/i386/acpica/acpi_machdep.c
+++ b/sys/i386/acpica/acpi_machdep.c
@@ -45,7 +45,8 @@ __FBSDID("$FreeBSD$");
 #include <machine/nexusvar.h>
 
 uint32_t acpi_resume_beep;
-SYSCTL_UINT(_debug_acpi, OID_AUTO, resume_beep, CTLFLAG_RWTUN, &acpi_resume_beep,
+TUNABLE_INT("debug.acpi.resume_beep", &acpi_resume_beep);
+SYSCTL_UINT(_debug_acpi, OID_AUTO, resume_beep, CTLFLAG_RW, &acpi_resume_beep,
     0, "Beep the PC speaker when resuming");
 
 uint32_t acpi_reset_video;
diff --git a/sys/i386/bios/apm.c b/sys/i386/bios/apm.c
index a4d3bd7..bf5071f 100644
--- a/sys/i386/bios/apm.c
+++ b/sys/i386/bios/apm.c
@@ -134,7 +134,8 @@ SYSCTL_INT(_machdep, OID_AUTO, apm_suspend_delay, CTLFLAG_RW, &apm_suspend_delay
 SYSCTL_INT(_machdep, OID_AUTO, apm_standby_delay, CTLFLAG_RW, &apm_standby_delay, 1, "");
 SYSCTL_INT(_debug, OID_AUTO, apm_debug, CTLFLAG_RW, &apm_debug, 0, "");
 
-SYSCTL_INT(_machdep, OID_AUTO, apm_swab_batt_minutes, CTLFLAG_RWTUN,
+TUNABLE_INT("machdep.apm_swab_batt_minutes", &apm_swab_batt_minutes);
+SYSCTL_INT(_machdep, OID_AUTO, apm_swab_batt_minutes, CTLFLAG_RW,
 	   &apm_swab_batt_minutes, 0, "Byte swap battery time value.");
 
 #ifdef PC98
diff --git a/sys/i386/i386/i686_mem.c b/sys/i386/i386/i686_mem.c
index 2721cfb..84db1ec 100644
--- a/sys/i386/i386/i686_mem.c
+++ b/sys/i386/i386/i686_mem.c
@@ -65,6 +65,7 @@ static char *mem_owner_bios = "BIOS";
 	(((curr) & ~MDF_ATTRMASK) | ((new) & MDF_ATTRMASK))
 
 static int mtrrs_disabled;
+TUNABLE_INT("machdep.disable_mtrrs", &mtrrs_disabled);
 SYSCTL_INT(_machdep, OID_AUTO, disable_mtrrs, CTLFLAG_RDTUN,
     &mtrrs_disabled, 0, "Disable i686 MTRRs.");
 
diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index ac41c27..3d92e6e 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -1231,7 +1231,8 @@ cpu_halt(void)
 void (*cpu_idle_hook)(sbintime_t) = NULL;	/* ACPI idle hook. */
 static int	cpu_ident_amdc1e = 0;	/* AMD C1E supported. */
 static int	idle_mwait = 1;		/* Use MONITOR/MWAIT for short idle. */
-SYSCTL_INT(_machdep, OID_AUTO, idle_mwait, CTLFLAG_RWTUN, &idle_mwait,
+TUNABLE_INT("machdep.idle_mwait", &idle_mwait);
+SYSCTL_INT(_machdep, OID_AUTO, idle_mwait, CTLFLAG_RW, &idle_mwait,
     0, "Use MONITOR/MWAIT for short idle");
 
 #define	STATE_RUNNING	0x0
diff --git a/sys/i386/i386/mp_watchdog.c b/sys/i386/i386/mp_watchdog.c
index b03d261..b1799a2 100644
--- a/sys/i386/i386/mp_watchdog.c
+++ b/sys/i386/i386/mp_watchdog.c
@@ -68,7 +68,8 @@ static int	watchdog_dontfire = 1;
 static int	watchdog_timer = -1;
 static int	watchdog_nmi = 1;
 
-SYSCTL_INT(_debug, OID_AUTO, watchdog_nmi, CTLFLAG_RWTUN, &watchdog_nmi, 0,
+TUNABLE_INT("debug.watchdog", &watchdog_cpu);
+SYSCTL_INT(_debug, OID_AUTO, watchdog_nmi, CTLFLAG_RW, &watchdog_nmi, 0,
     "IPI the boot processor with an NMI to enter the debugger");
 
 static struct callout	watchdog_callout;
diff --git a/sys/i386/i386/pmap.c b/sys/i386/i386/pmap.c
index 3085157..af8c9ff 100644
--- a/sys/i386/i386/pmap.c
+++ b/sys/i386/i386/pmap.c
@@ -225,8 +225,8 @@ SYSCTL_INT(_vm_pmap, OID_AUTO, pat_works, CTLFLAG_RD, &pat_works, 1,
     "Is page attribute table fully functional?");
 
 static int pg_ps_enabled = 1;
-SYSCTL_INT(_vm_pmap, OID_AUTO, pg_ps_enabled, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
-    &pg_ps_enabled, 0, "Are large page mappings enabled?");
+SYSCTL_INT(_vm_pmap, OID_AUTO, pg_ps_enabled, CTLFLAG_RDTUN, &pg_ps_enabled, 0,
+    "Are large page mappings enabled?");
 
 #define	PAT_INDEX_SIZE	8
 static int pat_index[PAT_INDEX_SIZE];	/* cache mode to PAT index conversion */
diff --git a/sys/i386/i386/trap.c b/sys/i386/i386/trap.c
index 6e4aba2..97254f2 100644
--- a/sys/i386/i386/trap.c
+++ b/sys/i386/i386/trap.c
@@ -158,12 +158,14 @@ extern int has_f00f_bug;
 
 #ifdef KDB
 static int kdb_on_nmi = 1;
-SYSCTL_INT(_machdep, OID_AUTO, kdb_on_nmi, CTLFLAG_RWTUN,
+SYSCTL_INT(_machdep, OID_AUTO, kdb_on_nmi, CTLFLAG_RW,
 	&kdb_on_nmi, 0, "Go to KDB on NMI");
+TUNABLE_INT("machdep.kdb_on_nmi", &kdb_on_nmi);
 #endif
 static int panic_on_nmi = 1;
-SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RWTUN,
+SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RW,
 	&panic_on_nmi, 0, "Panic on NMI");
+TUNABLE_INT("machdep.panic_on_nmi", &panic_on_nmi);
 static int prot_fault_translation = 0;
 SYSCTL_INT(_machdep, OID_AUTO, prot_fault_translation, CTLFLAG_RW,
 	&prot_fault_translation, 0, "Select signal to deliver on protection fault");
diff --git a/sys/i386/pci/pci_cfgreg.c b/sys/i386/pci/pci_cfgreg.c
index 5d57e89..cce4981 100644
--- a/sys/i386/pci/pci_cfgreg.c
+++ b/sys/i386/pci/pci_cfgreg.c
@@ -86,6 +86,7 @@ static int cfgmech;
 static int devmax;
 static struct mtx pcicfg_mtx;
 static int mcfg_enable = 1;
+TUNABLE_INT("hw.pci.mcfg", &mcfg_enable);
 SYSCTL_INT(_hw_pci, OID_AUTO, mcfg, CTLFLAG_RDTUN, &mcfg_enable, 0,
     "Enable support for PCI-e memory mapped config access");
 
diff --git a/sys/i386/pci/pci_pir.c b/sys/i386/pci/pci_pir.c
index 0d64cab..c275de0 100644
--- a/sys/i386/pci/pci_pir.c
+++ b/sys/i386/pci/pci_pir.c
@@ -117,6 +117,7 @@ SYSCTL_DECL(_hw_pci);
 #endif
 
 static uint32_t pci_irq_override_mask = PCI_IRQ_OVERRIDE_MASK;
+TUNABLE_INT("hw.pci.irq_override_mask", &pci_irq_override_mask);
 SYSCTL_INT(_hw_pci, OID_AUTO, irq_override_mask, CTLFLAG_RDTUN,
     &pci_irq_override_mask, PCI_IRQ_OVERRIDE_MASK,
     "Mask of allowed irqs to try to route when it has no good clue about\n"