Re: [PATCH] x86_64: check if Tom2 is enabled

[H. Peter Anvin]

Cyrill Gorcunov wrote:
> [Andi Kleen - Mon, Jan 21, 2008 at 07:03:27PM +0100]
> | 
> | > is it possible to change 'l' and 'h' to 'low' and 'high'?
> | > 'cause 'l' does look like '1' (one) number...
> | 
> | It would be fine for me for someone to implement safe_rdtscll() and get rid
> | of l and h everywhere. IMHO all the l and h accesses of MSRs are just harder
> | to read and error prone over the ll 64bit variants.
> | 
> | But I didn't want to add it just for this.
> | 
>
> clear enough, thanks

Actually, I think it depends on the specific MSR - some use the halves 
for different data, whereas others treat it as a large 64-bit object.

Ironically enough, the way the MSR interfaces were carried into the 
64-bit world makes the situation worse on 64 bits; edx:eax is the common 
way to represent a 64-bit value on 32 bits.

	-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/