Extend the meaning of the CTLFLAG_TUN flag to automatically check if

there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.

Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.

MFC after:	2 weeks
Sponsored by:	Mellanox Technologies

1 files changed, 2 insertions, 24 deletions

diff --git a/sys/net/netisr.c b/sys/net/netisr.c
index 7974cc8..049bbf1 100644
--- a/sys/net/netisr.c
+++ b/sys/net/netisr.c
@@ -149,8 +149,8 @@ static SYSCTL_NODE(_net, OID_AUTO, isr, CTLFLAG_RW, 0, "netisr");
 #define	NETISR_DISPATCH_POLICY_MAXSTR	20 /* Used for temporary buffers. */
 static u_int	netisr_dispatch_policy = NETISR_DISPATCH_POLICY_DEFAULT;
 static int	sysctl_netisr_dispatch_policy(SYSCTL_HANDLER_ARGS);
-SYSCTL_PROC(_net_isr, OID_AUTO, dispatch, CTLTYPE_STRING | CTLFLAG_RW |
-    CTLFLAG_TUN, 0, 0, sysctl_netisr_dispatch_policy, "A",
+SYSCTL_PROC(_net_isr, OID_AUTO, dispatch, CTLTYPE_STRING | CTLFLAG_RWTUN,
+    0, 0, sysctl_netisr_dispatch_policy, "A",
     "netisr dispatch policy");
 
 /*
@@ -160,13 +160,11 @@ SYSCTL_PROC(_net_isr, OID_AUTO, dispatch, CTLTYPE_STRING | CTLFLAG_RW |
  * We will create at most one thread per CPU.
  */
 static int	netisr_maxthreads = -1;		/* Max number of threads. */
-TUNABLE_INT("net.isr.maxthreads", &netisr_maxthreads);
 SYSCTL_INT(_net_isr, OID_AUTO, maxthreads, CTLFLAG_RDTUN,
     &netisr_maxthreads, 0,
     "Use at most this many CPUs for netisr processing");
 
 static int	netisr_bindthreads = 0;		/* Bind threads to CPUs. */
-TUNABLE_INT("net.isr.bindthreads", &netisr_bindthreads);
 SYSCTL_INT(_net_isr, OID_AUTO, bindthreads, CTLFLAG_RDTUN,
     &netisr_bindthreads, 0, "Bind netisr threads to CPUs.");
 
@@ -177,7 +175,6 @@ SYSCTL_INT(_net_isr, OID_AUTO, bindthreads, CTLFLAG_RDTUN,
  */
 #define	NETISR_DEFAULT_MAXQLIMIT	10240
 static u_int	netisr_maxqlimit = NETISR_DEFAULT_MAXQLIMIT;
-TUNABLE_INT("net.isr.maxqlimit", &netisr_maxqlimit);
 SYSCTL_UINT(_net_isr, OID_AUTO, maxqlimit, CTLFLAG_RDTUN,
     &netisr_maxqlimit, 0,
     "Maximum netisr per-protocol, per-CPU queue depth.");
@@ -189,7 +186,6 @@ SYSCTL_UINT(_net_isr, OID_AUTO, maxqlimit, CTLFLAG_RDTUN,
  */
 #define	NETISR_DEFAULT_DEFAULTQLIMIT	256
 static u_int	netisr_defaultqlimit = NETISR_DEFAULT_DEFAULTQLIMIT;
-TUNABLE_INT("net.isr.defaultqlimit", &netisr_defaultqlimit);
 SYSCTL_UINT(_net_isr, OID_AUTO, defaultqlimit, CTLFLAG_RDTUN,
     &netisr_defaultqlimit, 0,
     "Default netisr per-protocol, per-CPU queue limit if not set by protocol");
@@ -1120,10 +1116,6 @@ netisr_start_swi(u_int cpuid, struct pcpu *pc)
 static void
 netisr_init(void *arg)
 {
-	char tmp[NETISR_DISPATCH_POLICY_MAXSTR];
-	u_int dispatch_policy;
-	int error;
-
 	KASSERT(curcpu == 0, ("%s: not on CPU 0", __func__));
 
 	NETISR_LOCK_INIT();
@@ -1152,20 +1144,6 @@ netisr_init(void *arg)
 		netisr_bindthreads = 0;
 	}
 #endif
-
-	if (TUNABLE_STR_FETCH("net.isr.dispatch", tmp, sizeof(tmp))) {
-		error = netisr_dispatch_policy_from_str(tmp,
-		    &dispatch_policy);
-		if (error == 0 && dispatch_policy == NETISR_DISPATCH_DEFAULT)
-			error = EINVAL;
-		if (error == 0)
-			netisr_dispatch_policy = dispatch_policy;
-		else
-			printf(
-			    "%s: invalid dispatch policy %s, using default\n",
-			    __func__, tmp);
-	}
-
 	netisr_start_swi(curcpu, pcpu_find(curcpu));
 }
 SYSINIT(netisr_init, SI_SUB_SOFTINTR, SI_ORDER_FIRST, netisr_init, NULL);