Re: port-amd64/39283: Kernel crash on Dell Poweredge 2950

[David Laight <david%l8s.co.uk@localhost>]

On Mon, Dec 14, 2009 at 02:55:01PM +0000, Tobias Nygren wrote:
> The following reply was made to PR port-amd64/39283; it has been noted by 
> GNATS.
> 
> From: Tobias Nygren <tnn%NetBSD.org@localhost>
> To: gnats-bugs%NetBSD.org@localhost
> Cc: 
> Subject: Re: port-amd64/39283: Kernel crash on Dell Poweredge 2950
> Date: Mon, 14 Dec 2009 15:50:54 +0100
> 
>  With some local patches I've been able to reduce the panics to a
>  deadlock waiting for kva that never becomes availabe. It looks like
>  the underlying problem is in fact a resource leak.
>  
>  From ddb I've identified the following pool cache whose resource usage
>  looks highly suspicious to me.
>  
>  POOL CACHE ksiginfo: size 72, align 8, ioff 0, roflags 0x00000040
>          alloc 0xffffffff80d42f20
>          minitems 0, minpages 0, maxpages 4294967295, npages 264334
>          itemsperpage 56, nitems 21, nout 14802683, hardlimit 4294967295
>          nget 14809537, nfail 13, nput 6854
>          npagealloc 264337, npagefree 3, hiwat 264334, nidle 0
>          cpu layer hits 5450561 misses 14853292
>          cache layer hits 43741 misses 14809551
>          cache layer entry uncontended 14853283 contended 9
>          cache layer empty groups 0 full groups 0
>  
>  Are we aware of any issues related to ksiginfo leakage in 5.0/current?

No one has mentioned any, but I do recall something about signals being
queued to apps (rather than just being a bitmask). If something is
looping generating signals maybe there is a path which causes an
indefinite number to be queued (ksiginfo sounds like the item being queued!)

Perhaps something has ignored SIGSEGV!

        David

-- 
David Laight: david%l8s.co.uk@localhost