MPSAFE - Warning

Robert Watson rwatson at freebsd.org
Wed Nov 17 02:31:19 PST 2004


On Tue, 16 Nov 2004, Giuliano Cardozo Medalha wrote:

> I got some messages for my customized kernel, using IPsec and IPv6: 
> 
> WARNING: MPSAFE network stack disabled, expect reduced performance. 
> 
> My kernel have the following option: 
> 
> options NET_WITH_GIANT
> 
> How is possible to correct this warning

The problem here is the KAME IPSEC code, which is not yet able to run
without the Giant lock.  For those using only IPv4, FAST_IPSEC is an
option, as it can run without the Giant lock.  Unfortunately, until the
KAME IPSEC code is locked down, your system will need to run with Giant.
The good news is that it will probably perform well, just not optimally.
If you don't notice any specific performance related problems, you can
safely ignore the error.

BTW, when compiling with KAME IPSEC, debug.mpsafenet=1 will be forced, you
don't actually need the NET_WITH_GIANT option; that option basically does
the same thing as the statement in the KAME code that says
"NET_NEEDS_GIANT"). 

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert at fledge.watson.org      Principal Research Scientist, McAfee Research




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