Rename the kern.vm.kmem.size tunable to the more logical vm.kmem_size. To

assure backward compatibility (conditional on !BURN_BRIDGES), look it up
by its old name first, and log a warning (but accept the setting) if it
was found.  If both the old and new name are defined, the new name takes
precedence.

Also export vm.kmem_size as a read-only sysctl variable; I find it hard to
tune a parameter when I don't know its default value, especially when that
default value is computed at boot time.

1 files changed, 7 insertions, 1 deletions

diff --git a/sys/kern/kern_malloc.c b/sys/kern/kern_malloc.c
index 62fc909..cbcbe9e 100644
--- a/sys/kern/kern_malloc.c
+++ b/sys/kern/kern_malloc.c
@@ -133,6 +133,8 @@ struct {
 };
 
 u_int vm_kmem_size;
+SYSCTL_UINT(_vm, OID_AUTO, kmem_size, CTLFLAG_RD, &vm_kmem_size, 0,
+    "Size of kernel memory");
 
 /*
  * The malloc_mtx protects the kmemstatistics linked list.
@@ -444,7 +446,11 @@ kmeminit(dummy)
 #endif
 
 	/* Allow final override from the kernel environment */
-	TUNABLE_INT_FETCH("kern.vm.kmem.size", &vm_kmem_size);
+#ifndef BURN_BRIDGES
+	if (TUNABLE_INT_FETCH("kern.vm.kmem.size", &vm_kmem_size) != 0)
+		printf("kern.vm.kmem.size is now called vm.kmem_size!\n");
+#endif
+	TUNABLE_INT_FETCH("vm.kmem_size", &vm_kmem_size);
 
 	/*
 	 * Limit kmem virtual size to twice the physical memory.