From owner-freebsd-hackers@FreeBSD.ORG  Fri Nov  4 09:49:09 2005
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Date: Fri, 4 Nov 2005 20:49:05 +1100
From: Peter Jeremy <PeterJeremy@optushome.com.au>
To: kamal kc <kamal_ckk@yahoo.com>
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Cc: freebsd <freebsd-hackers@freebsd.org>,
	Giorgos Keramidas <keramida@linux.gr>
Subject: Re: allocating 14KB memory per packet compression/decompression
	results in vm_fault
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[dropping -net]
On Thu, 2005-Nov-03 22:56:30 -0800, kamal kc wrote:
>as i said before the compression/decompression works
>fine. but soon the kernel would panic with one 
>of the vm_fault: error message.

What's the exact panic and traceback?  Have you enabled the various
sanity checks (WITNESS, DEBUG_MEMGUARD, INVARIANTS)?

>what would be the best possible way to 
>allocate/deallocate 14KB memory per packet without 
>causing vm_faults ?? 

The most efficient way would be to statically allocate the dictionary
and string tables.  The downside is that you then need to serialise
the [de]compression.

You could look at zone(9) as an alternative to malloc(9).

>is there anything i am missing ??

- Are you correctly allocating the mbuf for the outgoing packet correctly?
- Are you correctly freeing the mbuf for the incoming packet?
- Are you sure that you're not writing outside the bounds of one of the
  memory blocks you're allocating?

-- 
Peter Jeremy