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Re: [Xen-devel] [PATCH v2 03/23] x86: zero BSS using stosl instead of stosb

>>> Daniel Kiper <daniel.kiper@xxxxxxxxxx> 07/21/15 8:23 PM >>>
>On Tue, Jul 21, 2015 at 03:37:48AM -0600, Jan Beulich wrote:
>> >>> On 20.07.15 at 16:28, <daniel.kiper@xxxxxxxxxx> wrote:
>> ... because of ??? Nowadays - with X86_FEATURE_ERMS - rep stosb
>> is expected to be faster than rep stosl.
>OK, I did not know about that. However, as I know this feature
>was introduced in 2012 with Ivy Bridge. So, I suppose that there
>are still a lot of machines in the wild which does not support it.
>Anyway, because this code is not performance critical I am not going
>to insist on one or another solution. However, Andrew suggested that
>thing, so, please agree with him in which direction we should go.
>I will do what you agree.

ISTR having seen a similar patch from him(?), maybe in another area
of code, before (or was it v1 of this one?), which I responded to with the
same as above.


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