RE: [Xen-devel] A useless short jmp?

["Li, Xin B" <xin.b.li@xxxxxxxxx>]

>> According to Intel Spec, it's useless, do we have any 
>special reason to
>> have it there?
>> BTW why put mov $1, %bl between lmsw and it's corresponding ljmp?
>
>Hmmm... I'm sure I read somewhere about a jmp to clear the 
>prefetch queue,


Surely you did read it :-), in the latest Spec (version of May 2007),
in17.29.3 Enabling and Disabling Paging, it's said a near jump should be
executed after set or clear PG flag in CR0, but it's a different case
since we are setting or clearing PE flag, probably plus PG changes too.

-Xin 

>but reading the appropriate manual pages now I see I only need 
>the ljmp.
>I'll fix that and also move the write to %bx somewhere more sensible.
>
> Thanks,
> Keir
>

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