thr3ads.net - freebsd stable - panic: mutex vm object not owned [Mar 2005]

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Gavin Atkinson

2005-Mar-11 10:59 UTC

panic: mutex vm object not owned

Hi,

I'm tracking RELENG_5 and since my last update I can no longer start X
without getting the following panic:

panic: mutex vm object not owned at /usr/src/sys/vm/vm_page.c:334
cpuid = 0
KDB: enter: panic
[ thread pid 2762 tid 100116 ]
stopped at         kdb_enter+0x2b:   nop

At which point the machine hangs solid (note this is over a serial console
- it is after X has claimed the display).

I've done a binary chop to find where the bug was introduced, and it
started at some point between 19:00 on 2005/02/25 and 00:00 on 2005/02/26.
The MFC to vm_page.c which added the assertion I'm tripping up on happened
between those two points:
$FreeBSD: src/sys/vm/vm_page.c,v 1.290.2.4 2005/02/25 23:38:22 alc Exp $

vm_page.c:334 seems to correspond to the line
    VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
within vm_page_wakeup()

Any suggestions?  I'll try to coerce it into generating a backtrace but
given the machine wedges before even giving the DDB prompt I'm not sure
I'll be able to.

Thanks,

Gavin

Alan Cox

2005-Mar-11 11:04 UTC

head link

panic: mutex vm object not owned

On Fri, Mar 11, 2005 at 06:59:02PM +0000, Gavin Atkinson
wrote:> 
> Hi,
> 
> I'm tracking RELENG_5 and since my last update I can no longer start X
> without getting the following panic:
> 
> panic: mutex vm object not owned at /usr/src/sys/vm/vm_page.c:334
> cpuid = 0
> KDB: enter: panic
> [ thread pid 2762 tid 100116 ]
> stopped at         kdb_enter+0x2b:   nop
> 
> At which point the machine hangs solid (note this is over a serial console
> - it is after X has claimed the display).
> 
> I've done a binary chop to find where the bug was introduced, and it
> started at some point between 19:00 on 2005/02/25 and 00:00 on 2005/02/26.
> The MFC to vm_page.c which added the assertion I'm tripping up on
happened
> between those two points:
> $FreeBSD: src/sys/vm/vm_page.c,v 1.290.2.4 2005/02/25 23:38:22 alc Exp $
> 
> vm_page.c:334 seems to correspond to the line
>     VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
> within vm_page_wakeup()
> 
> Any suggestions?  I'll try to coerce it into generating a backtrace but
> given the machine wedges before even giving the DDB prompt I'm not sure
> I'll be able to.
> 
Are you using an Nvidia driver?

Regards,
Alan

Alan Cox

2005-Mar-11 11:20 UTC

head link

panic: mutex vm object not owned

I'm pretty sure that I understand the cause.  Please apply and test
the attached patch.

Regards,
Alan
-------------- next part --------------
Index: pci/agp.c
==================================================================RCS file:
/home/ncvs/src/sys/pci/agp.c,v
retrieving revision 1.45
diff -u -r1.45 agp.c
--- pci/agp.c	16 Aug 2004 12:25:48 -0000	1.45
+++ pci/agp.c	11 Mar 2005 19:17:09 -0000
@@ -501,6 +501,7 @@
 	 * because vm_page_grab() used with VM_ALLOC_RETRY may
 	 * block and we can't hold a mutex while blocking.
 	 */
+	VM_OBJECT_LOCK(mem->am_obj);
 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
 		/*
 		 * Find a page from the object and wire it
@@ -509,18 +510,18 @@
 		 * AGP_PAGE_SIZE. If this is the first call to bind,
 		 * the pages will be allocated and zeroed.
 		 */
-		VM_OBJECT_LOCK(mem->am_obj);
 		m = vm_page_grab(mem->am_obj, OFF_TO_IDX(i),
 		    VM_ALLOC_WIRED | VM_ALLOC_ZERO | VM_ALLOC_RETRY);
-		VM_OBJECT_UNLOCK(mem->am_obj);
 		AGP_DPF("found page pa=%#x\n", VM_PAGE_TO_PHYS(m));
 	}
+	VM_OBJECT_UNLOCK(mem->am_obj);
 
 	mtx_lock(&sc->as_lock);
 
 	if (mem->am_is_bound) {
 		device_printf(dev, "memory already bound\n");
 		error = EINVAL;
+		VM_OBJECT_LOCK(mem->am_obj);
 		goto bad;
 	}
 	
@@ -532,10 +533,9 @@
 	 * (i.e. use alpha_XXX_dmamap()). I don't have access to any
 	 * alpha AGP hardware to check.
 	 */
+	VM_OBJECT_LOCK(mem->am_obj);
 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
-		VM_OBJECT_LOCK(mem->am_obj);
 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(i));
-		VM_OBJECT_UNLOCK(mem->am_obj);
 
 		/*
 		 * Install entries in the GATT, making sure that if
@@ -566,6 +566,7 @@
 		vm_page_wakeup(m);
 		vm_page_unlock_queues();
 	}
+	VM_OBJECT_UNLOCK(mem->am_obj);
 
 	/*
 	 * Flush the cpu cache since we are providing a new mapping
@@ -586,7 +587,7 @@
 	return 0;
 bad:
 	mtx_unlock(&sc->as_lock);
-	VM_OBJECT_LOCK(mem->am_obj);
+	VM_OBJECT_LOCK_ASSERT(mem->am_obj, MA_OWNED);
 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(i));
 		vm_page_lock_queues();
Index: pci/agp_i810.c
==================================================================RCS file:
/home/ncvs/src/sys/pci/agp_i810.c,v
retrieving revision 1.30.2.1
diff -u -r1.30.2.1 agp_i810.c
--- pci/agp_i810.c	1 Mar 2005 08:11:50 -0000	1.30.2.1
+++ pci/agp_i810.c	11 Mar 2005 19:15:45 -0000
@@ -609,13 +609,10 @@
 		vm_page_t m;
 
 		VM_OBJECT_LOCK(mem->am_obj);
-		m = vm_page_grab(mem->am_obj, 0,
+		m = vm_page_grab(mem->am_obj, 0, VM_ALLOC_NOBUSY |
 		    VM_ALLOC_WIRED | VM_ALLOC_ZERO | VM_ALLOC_RETRY);
 		VM_OBJECT_UNLOCK(mem->am_obj);
-		vm_page_lock_queues();
 		mem->am_physical = VM_PAGE_TO_PHYS(m);
-		vm_page_wakeup(m);
-		vm_page_unlock_queues();
 	} else {
 		mem->am_physical = 0;
 	}

freebsd stable - Mar 2005 - panic: mutex vm object not owned

panic: mutex vm object not owned

panic: mutex vm object not owned

panic: mutex vm object not owned