Re: [RFC 00/15] x86_64: Optimize percpu accesses

[H. Peter Anvin]

Jeremy Fitzhardinge wrote:
> Percpu on i386 hasn't been a point of discussion.  It works fine, and 
> has been working fine for a long time.  The same mechanism would work 
> fine on x86-64.  Its only "issue" is that it doesn't support the broken 
> gcc abi for stack-protector.
>
> The problem is all zero-based percpu on x86-64.

Well, x86-64 has *two* issues: limited range of offsets (regardless of 
if we do RIP-relative or not), and the stack-protector ABI.

I'm still trying to reproduce Mike's setup, but I suspect it can be 
switched to RIP-relative for the fixed-offset (static) stuff; for the 
dynamic stuff it's all via pointers anyway so the offsets don't matter.

	-hpa
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/