uma_zalloc_arg complaining about non-sleepable locks

[John Baldwin]

On Tuesday 26 January 2010 2:33:37 am Peter Jeremy wrote:
> I have just upgraded to 8-STABLE/amd64 from about 18 hours ago and am
> now getting regular (the following pair of messages about every
> minute) compaints as follows:
> 
> kernel: uma_zalloc_arg: zone "mbuf" with the following non-sleepable locks held:
> kernel: exclusive sleep mutex sp_lock (sp_lock) r = 0 (0xffffff000460bb00) locked @ /usr/src/sys/rpc/svc.c:1098
> kernel: KDB: stack backtrace:
> kernel: db_trace_self_wrapper() at db_trace_self_wrapper+0x2a
> kernel: _witness_debugger() at _witness_debugger+0x2c
> kernel: witness_warn() at witness_warn+0x2c2
> kernel: uma_zalloc_arg() at uma_zalloc_arg+0x29d
> kernel: nfs_realign() at nfs_realign+0x5f
> kernel: fha_assign() at fha_assign+0x2d8
> kernel: svc_run_internal() at svc_run_internal+0x1ee
> kernel: svc_thread_start() at svc_thread_start+0xb
> kernel: fork_exit() at fork_exit+0x112
> kernel: fork_trampoline() at fork_trampoline+0xe
> kernel: --- trap 0xc, rip = 0x80069e04c, rsp = 0x7fffffffe6d8, rbp = 0x5 ---
> kernel: uma_zalloc_arg: zone "mbuf" with the following non-sleepable locks held:
> kernel: exclusive sleep mutex sp_lock (sp_lock) r = 0 (0xffffff000460bb00) locked @ /usr/src/sys/rpc/svc.c:1098
> kernel: KDB: stack backtrace:
> kernel: db_trace_self_wrapper() at db_trace_self_wrapper+0x2a
> kernel: _witness_debugger() at _witness_debugger+0x2c
> kernel: witness_warn() at witness_warn+0x2c2
> kernel: uma_zalloc_arg() at uma_zalloc_arg+0x29d
> kernel: nfs_realign() at nfs_realign+0x5f
> kernel: fha_assign() at fha_assign+0x2d8
> kernel: svc_run_internal() at svc_run_internal+0x1ee
> kernel: svc_thread_start() at svc_thread_start+0xb
> kernel: fork_exit() at fork_exit+0x112
> kernel: fork_trampoline() at fork_trampoline+0xe
> kernel: --- trap 0xc, rip = 0x80069e04c, rsp = 0x7fffffffe6d8, rbp = 0x5 ---
> 
> It looks like NFS is missing some lock/unlock pairs.  Has anyone else
> seen this?  And does anyone have a fix?

I suspect this was caused by the recent alignment fixes to NFS.  I've cc'd
Marius.

-- 
John Baldwin