On Fri, May 20, 2005 at 05:15:36PM +0400, Gleb Smirnoff wrote: > Jeremie, > > On Fri, May 20, 2005 at 03:10:32PM +0200, Jeremie Le Hen wrote: > J> > according to the fact that the panic occured in dereferncing mbuf pointer > J> > your kernel is compiled without INVARIANTS. > J> > > J> > Please compile it with INVARIANTS. This will probably help to trigger > panic > J> > earlier, and it will be more clear. > J> > J> a quick look at src/conf/NOTES reveals the following : > J> %%% > J> # > J> # The INVARIANTS option is used in a number of source files to enable > J> # extra sanity checking of internal structures. This support is not > J> # enabled by default because of the extra time it would take to check > J> # for these conditions, which can only occur as a result of > J> # programming errors. > J> # > J> %%% > J> > J> I'm going to recompile my kernel with INVARIANTS but I wonder in > J> which order of magniture it will slow my kernel down. In other words, > J> what does INVARIANTS do concretely, shall I expect a performance drop > J> like WITNESS does ? > > No. The performance loss is _much_ less significant than in WITNESS case. > You probably will not notice it.
Actually, INVARIANTS causes about a 10% penalty on wall clock time on 5.x and above. Kris
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