Module Name: src
Committed By: mhitch
Date: Sun Sep 4 01:15:14 UTC 2011
Modified Files:
src/sys/arch/xen/xen [cherry-xenmp]: xengnt.c
Log Message:
Use a mutex to protect updates to gnt_entries. Fixes a KASSERT panic
with an MP kernel.
To generate a diff of this commit:
cvs rdiff -u -r1.18.2.1 -r1.18.2.2 src/sys/arch/xen/xen/xengnt.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/xen/xen/xengnt.c
diff -u src/sys/arch/xen/xen/xengnt.c:1.18.2.1 src/sys/arch/xen/xen/xengnt.c:1.18.2.2
--- src/sys/arch/xen/xen/xengnt.c:1.18.2.1 Thu Jun 23 14:19:50 2011
+++ src/sys/arch/xen/xen/xengnt.c Sun Sep 4 01:15:13 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: xengnt.c,v 1.18.2.1 2011/06/23 14:19:50 cherry Exp $ */
+/* $NetBSD: xengnt.c,v 1.18.2.2 2011/09/04 01:15:13 mhitch Exp $ */
/*
* Copyright (c) 2006 Manuel Bouyer.
@@ -26,7 +26,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xengnt.c,v 1.18.2.1 2011/06/23 14:19:50 cherry Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xengnt.c,v 1.18.2.2 2011/09/04 01:15:13 mhitch Exp $");
#include <sys/types.h>
#include <sys/param.h>
@@ -35,6 +35,7 @@
#include <sys/queue.h>
#include <sys/extent.h>
#include <sys/kernel.h>
+#include <sys/mutex.h>
#include <uvm/uvm.h>
#include <xen/hypervisor.h>
@@ -62,6 +63,8 @@
/* empty entry in the list */
#define XENGNT_NO_ENTRY 0xffffffff
+static kmutex_t gnt_mutex;
+
/* VM address of the grant table */
grant_entry_t *grant_table;
@@ -101,6 +104,7 @@
gnt_entries[i] = XENGNT_NO_ENTRY;
last_gnt_entry = 0;
+ mutex_init(&gnt_mutex, MUTEX_DEFAULT, IPL_VM);
xengnt_resume();
}
@@ -192,13 +196,13 @@
xengnt_get_entry(void)
{
grant_ref_t entry;
- int s = splvm();
static struct timeval xengnt_nonmemtime;
static const struct timeval xengnt_nonmemintvl = {5,0};
+ mutex_enter(&gnt_mutex);
if (last_gnt_entry == 0) {
if (xengnt_more_entries()) {
- splx(s);
+ mutex_exit(&gnt_mutex);
if (ratecheck(&xengnt_nonmemtime, &xengnt_nonmemintvl))
printf("xengnt_get_entry: out of grant "
"table entries\n");
@@ -209,7 +213,7 @@
last_gnt_entry--;
entry = gnt_entries[last_gnt_entry];
gnt_entries[last_gnt_entry] = XENGNT_NO_ENTRY;
- splx(s);
+ mutex_exit(&gnt_mutex);
KASSERT(entry != XENGNT_NO_ENTRY);
KASSERT(last_gnt_entry >= 0);
KASSERT(last_gnt_entry <= gnt_max_grant_frames * NR_GRANT_ENTRIES_PER_PAGE);
@@ -222,13 +226,13 @@
static void
xengnt_free_entry(grant_ref_t entry)
{
- int s = splvm();
+ mutex_enter(&gnt_mutex);
KASSERT(gnt_entries[last_gnt_entry] == XENGNT_NO_ENTRY);
KASSERT(last_gnt_entry >= 0);
KASSERT(last_gnt_entry <= gnt_max_grant_frames * NR_GRANT_ENTRIES_PER_PAGE);
gnt_entries[last_gnt_entry] = entry;
last_gnt_entry++;
- splx(s);
+ mutex_exit(&gnt_mutex);
}
int
