but withoutI WITNESS and INVARIANTS ?

[Kris Kennaway]

On Fri, May 14, 2004 at 05:42:09PM +0400, Roman Kurakin wrote:

> The possibility that by disabling this debug stuff you will get some 
> instability is
> very very .... very low :-)
> By turning them off you will get improved performance.
> By the way they are dissabled by default on every release.

Not so low..it changes the timings of operations, which can expose
race conditions.  One of my SMP machines locks up every couple of
days(nothing on console, does not respond to DDB) when WITNESS and
INVARIANTS are disabled, or when they are enabled but WITNESS_SKIPSPIN
is enabled.  Since I turned off WITNESS_SKIPSPIN a few weeks ago the
system has been stable (although very slow).

:-(

Kris
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