で、パッチの中身を呼んで見ましたが、amd64も同じパッチあたってはいるけど、
HTT問題なので、AMDなCPUには関係なさげ。

で、パッチ内にこんな記述が。

+ /*
+ * Work out if hyperthreading is *really* enabled. This
+ * is made really ugly by the fact that processors lie: Dual
+ * core processors claim to be hyperthreaded even when they're
+ * not, presumably because they want to be treated the same
+ * way as HTT with respect to per-cpu software licensing.
+ * At the time of writing (May 12, 2005) the only hyperthreaded
+ * cpus are from Intel, and Intel's dual-core processors can be
+ * identified via the "deterministic cache parameters" cpuid
+ * calls.
+ */