Messages in this thread | | | Date | Fri, 30 May 2008 19:25:06 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: [PATCH 3/3] 64-bit futexes: x86 support |
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On Fri, 30 May 2008, Ulrich Drepper wrote: > > +#ifdef CONFIG_X86_32 > + /* Not all 32-bit machines support 8-byte cmpxchg. We just > + unconditionally perform a runtime check for the feature. */ > + if ((op & FUTEX_FLAG_64) && !boot_cpu_has(X86_FEATURE_CX8)) > + return -ENOSYS; > +#endif
Also, doesn't this mean that effectively you have given up on any CPU before the Pentium entirely?
Not that I want to take the patches _anyway_, but it seems doubly stupid. Those things are going to be UP machines, so you could have just emulated it with no correctness issues by disabling preemption.
Linus
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