if_sge related panics

[Nikolay Denev]

On May 24, 2010, at 4:48 PM, John Baldwin wrote:

> On Monday 24 May 2010 6:35:01 am Nikolay Denev wrote:
>> On May 24, 2010, at 8:57 AM, Nikolay Denev wrote:
>> 
>>> Hi,
>>> 
>>> Recently I started to experience a if_sge(4) related panic.
>>> It happens almost every time I try to download a torrent file for example.
>>> Copying of large files over NFS seem not to trigger it, but I haven't tested extensively.
>>> 
>>> Here is the panic message :
>>> 
>>> Fatal trap 12: page fault while in kernel mode
>>> cpuid = 0; apic id = 00
>>> fault virtual address		= 0x8
>>> fault code				= supervisor write data, page not present
>>> instruction pointer		= 0x20:0xffffffff80230413
>>> stack pointer				= 0x28:0xffffff80001e9280
>>> frame pointer			= 0x28:0xffffff80001e9510
>>> code segment			= base 0x0, limit 0xfffff, type 0x1b
>>> 						= DPL 0, pres 1, long 1, def32 0, gran 1
>>> processor eflags			= interrupt enabled, resume, IOPL = 0
>>> current process			= 12 (irq19: sge0)
>>> trap number				= 12
>>> panic: page fault
>>> cpuid = 0
>>> Uptime: 1d20h56m20s
>>> Cannot dump. Device not defined or unavailable
>>> Automatic reboot in 15 seconds - press a key on the console to abort
>>> Sleeping thread (tid 100039, pid 12) owns a non-sleepable lock
>>> 
>>> My swap is on a zvol, so I don't have dump. I'll try to attach a disk on the eSATA port and dump there if needed.
>> 
>> Here is some info from the crashdump :
>> 
>> (kgdb) #0  doadump () at pcpu.h:223
>> #1  0xffffffff802fb149 in boot (howto=260)
>>    at /usr/src/sys/kern/kern_shutdown.c:416
>> #2  0xffffffff802fb57c in panic (fmt=0xffffffff8055d564 "%s")
>>    at /usr/src/sys/kern/kern_shutdown.c:590
>> #3  0xffffffff805055b8 in trap_fatal (frame=0xffffff000288a3e0, eva=Variable "eva" is not available.
>> )
>>    at /usr/src/sys/amd64/amd64/trap.c:777
>> #4  0xffffffff805059dc in trap_pfault (frame=0xffffff80001e91d0, usermode=0)
>>    at /usr/src/sys/amd64/amd64/trap.c:693
>> #5  0xffffffff805061c5 in trap (frame=0xffffff80001e91d0)
>>    at /usr/src/sys/amd64/amd64/trap.c:451
>> #6  0xffffffff804eb977 in calltrap ()
>>    at /usr/src/sys/amd64/amd64/exception.S:223
>> #7  0xffffffff80230413 in sge_start_locked (ifp=0xffffff000270d800)
>>    at /usr/src/sys/dev/sge/if_sge.c:1591
> 
> Try this.  sge_encap() can sometimes return an error with m_head set to NULL:
> 
> Index: if_sge.c
> ===================================================================
> --- if_sge.c	(revision 208375)
> +++ if_sge.c	(working copy)
> @@ -1588,7 +1588,8 @@
> 		if (m_head == NULL)
> 			break;
> 		if (sge_encap(sc, &m_head)) {
> -			IFQ_DRV_PREPEND(&ifp->if_snd, m_head);
> +			if (m_head != NULL)
> +				IFQ_DRV_PREPEND(&ifp->if_snd, m_head);
> 			ifp->if_drv_flags |= IFF_DRV_OACTIVE;
> 			break;
> 		}
> 
> -- 
> John Baldwin

Thanks, patch applied. Will let you know how it goes.

--
Niki