Messages in this thread | | | Date | Sat, 16 Jun 2007 07:56:55 -0600 | From | Matthew Wilcox <> | Subject | Re: [PATCH] Introduce compat_u64 and compat_s64 types |
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On Sat, Jun 16, 2007 at 12:34:11PM +0100, David Woodhouse wrote: > You're right. My question was probably not relevant -- all these 64-bit > architectures cope with misaligned loads anyway. If we ever have to deal > with 32-bit compat on a 64-bit architecture which can't handle > misalignment, I'm just going to hide under my desk and never come out.
... 32-bit compat on a 64-bit architecture where the 32-bit architecture aligned 64-bit quantities to 32-bit boundaries ...
> > On x86_64, misaligned loads are always ok, so gcc never needs to > > care about this, even attribute((packed)) does not cause byte access > > here. > > IA64 too, but it'll be handled there too -- either naturally or by > fixups; it doesn't matter.
Yes. iirc, McKinley and later handle misaligned loads within a cacheline without interrupting. Merced would interrupt on every misaligned load. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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