From f8ccf82a4cbd9bad3b2e4241c77cc9a258a92616 Mon Sep 17 00:00:00 2001
From: Andre Oppermann <andre@FreeBSD.org>
Date: Fri, 8 Mar 2013 10:14:58 +0000
Subject: [PATCH] Move the auto-sizing of the callout array from init_param2()
 to kern_timeout_callwheel_alloc() where it is actually used.

This is a mechanical move and no tuning parameters are changed.

The pre-allocated callout array is only used for legacy timeout(9)
calls and is only allocated and active on cpu0.  Eventually all
remaining users of timeout(9) should switch to the callout_* API.

Reviewed by:	davide
---
 sys/kern/kern_timeout.c | 14 ++++++++++++++
 sys/kern/subr_param.c   | 12 ------------
 sys/sys/callout.h       |  2 --
 3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/sys/kern/kern_timeout.c b/sys/kern/kern_timeout.c
index df459cdce93c..ecc65fc44928 100644
--- a/sys/kern/kern_timeout.c
+++ b/sys/kern/kern_timeout.c
@@ -47,6 +47,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/systm.h>
 #include <sys/bus.h>
 #include <sys/callout.h>
+#include <sys/file.h>
 #include <sys/interrupt.h>
 #include <sys/kernel.h>
 #include <sys/ktr.h>
@@ -101,6 +102,11 @@ SYSCTL_INT(_debug, OID_AUTO, to_avg_mpcalls_dir, CTLFLAG_RD, &avg_mpcalls_dir,
     0, "Average number of MP direct callouts made per callout_process call. "
     "Units = 1/1000");
 #endif
+
+static int ncallout;
+SYSCTL_INT(_kern, OID_AUTO, ncallout, CTLFLAG_RDTUN, &ncallout, 0,
+    "Number of entries in callwheel and size of timeout() preallocation");
+
 /*
  * TODO:
  *	allocate more timeout table slots when table overflows.
@@ -252,6 +258,14 @@ kern_timeout_callwheel_alloc(caddr_t v)
 
 	timeout_cpu = PCPU_GET(cpuid);
 	cc = CC_CPU(timeout_cpu);
+
+	/*
+	 * Calculate the size of the callout wheel and the preallocated
+	 * timeout() structures.
+	 */
+	ncallout = imin(16 + maxproc + maxfiles, 18508);
+	TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
+
 	/*
 	 * Calculate callout wheel size, should be next power of two higher
 	 * than 'ncallout'.
diff --git a/sys/kern/subr_param.c b/sys/kern/subr_param.c
index 0a3580bea1ad..825a3a032f7a 100644
--- a/sys/kern/subr_param.c
+++ b/sys/kern/subr_param.c
@@ -91,7 +91,6 @@ int	maxprocperuid;			/* max # of procs per user */
 int	maxfiles;			/* sys. wide open files limit */
 int	maxfilesperproc;		/* per-proc open files limit */
 int	msgbufsize;			/* size of kernel message buffer */
-int	ncallout;			/* maximum # of timer events */
 int	nbuf;
 int	ngroups_max;			/* max # groups per process */
 int	nswbuf;
@@ -109,8 +108,6 @@ u_long	sgrowsiz;			/* amount to grow stack */
 
 SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN, &hz, 0,
     "Number of clock ticks per second");
-SYSCTL_INT(_kern, OID_AUTO, ncallout, CTLFLAG_RDTUN, &ncallout, 0,
-    "Number of pre-allocated timer events");
 SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN, &nbuf, 0,
     "Number of buffers in the buffer cache");
 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN, &nswbuf, 0,
@@ -326,15 +323,6 @@ init_param2(long physpages)
 	nbuf = NBUF;
 	TUNABLE_INT_FETCH("kern.nbuf", &nbuf);
 
-	/*
-	 * XXX: Does the callout wheel have to be so big?
-	 *
-	 * Clip callout to result of previous function of maxusers maximum
-	 * 384.  This is still huge, but acceptable.
-	 */
-	ncallout = imin(16 + maxproc + maxfiles, 18508);
-	TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
-
 	/*
 	 * The default for maxpipekva is min(1/64 of the kernel address space,
 	 * max(1/64 of main memory, 512KB)).  See sys_pipe.c for more details.
diff --git a/sys/sys/callout.h b/sys/sys/callout.h
index 7a4dec9be1ba..9e3eb9031122 100644
--- a/sys/sys/callout.h
+++ b/sys/sys/callout.h
@@ -63,8 +63,6 @@ struct callout_handle {
 };
 
 #ifdef _KERNEL
-extern int ncallout;
-
 #define	callout_active(c)	((c)->c_flags & CALLOUT_ACTIVE)
 #define	callout_deactivate(c)	((c)->c_flags &= ~CALLOUT_ACTIVE)
 #define	callout_drain(c)	_callout_stop_safe(c, 1)