Adjust some variables (mostly related to the buffer cache) that hold

address space sizes to be longs instead of ints.  Specifically, the follow
values are now longs: runningbufspace, bufspace, maxbufspace,
bufmallocspace, maxbufmallocspace, lobufspace, hibufspace, lorunningspace,
hirunningspace, maxswzone, maxbcache, and maxpipekva.  Previously, a
relatively small number (~ 44000) of buffers set in kern.nbuf would result
in integer overflows resulting either in hangs or bogus values of
hidirtybuffers and lodirtybuffers.  Now one has to overflow a long to see
such problems.  There was a check for a nbuf setting that would cause
overflows in the auto-tuning of nbuf.  I've changed it to always check and
cap nbuf but warn if a user-supplied tunable would cause overflow.

Note that this changes the ABI of several sysctls that are used by things
like top(1), etc., so any MFC would probably require a some gross shims
to allow for that.

MFC after:	1 month

1 files changed, 6 insertions, 6 deletions

diff --git a/sys/kern/subr_param.c b/sys/kern/subr_param.c
index f626ddb..3ec49e8 100644
--- a/sys/kern/subr_param.c
+++ b/sys/kern/subr_param.c
@@ -89,9 +89,9 @@ int	maxfilesperproc;		/* per-proc open files limit */
 int	ncallout;			/* maximum # of timer events */
 int	nbuf;
 int	nswbuf;
-int	maxswzone;			/* max swmeta KVA storage */
-int	maxbcache;			/* max buffer cache KVA storage */
-int	maxpipekva;			/* Limit on pipe KVA */
+long	maxswzone;			/* max swmeta KVA storage */
+long	maxbcache;			/* max buffer cache KVA storage */
+u_long	maxpipekva;			/* Limit on pipe KVA */
 int 	vm_guest;			/* Running as virtual machine guest? */
 u_long	maxtsiz;			/* max text size */
 u_long	dfldsiz;			/* initial data size limit */
@@ -203,11 +203,11 @@ init_param1(void)
 #ifdef VM_SWZONE_SIZE_MAX
 	maxswzone = VM_SWZONE_SIZE_MAX;
 #endif
-	TUNABLE_INT_FETCH("kern.maxswzone", &maxswzone);
+	TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone);
 #ifdef VM_BCACHE_SIZE_MAX
 	maxbcache = VM_BCACHE_SIZE_MAX;
 #endif
-	TUNABLE_INT_FETCH("kern.maxbcache", &maxbcache);
+	TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache);
 
 	maxtsiz = MAXTSIZ;
 	TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz);
@@ -282,7 +282,7 @@ init_param3(long kmempages)
 	maxpipekva = (kmempages / 20) * PAGE_SIZE;
 	if (maxpipekva < 512 * 1024)
 		maxpipekva = 512 * 1024;
-	TUNABLE_INT_FETCH("kern.ipc.maxpipekva", &maxpipekva);
+	TUNABLE_ULONG_FETCH("kern.ipc.maxpipekva", &maxpipekva);
 }
 
 /*