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Re: [PATCH 1/2] x86/time: use relative counts in calibration loops
- To: Jan Beulich <jbeulich@xxxxxxxx>
- From: Roger Pau Monné <roger.pau@xxxxxxxxxx>
- Date: Wed, 12 Jan 2022 11:18:19 +0100
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- Cc: "xen-devel@xxxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxxx>, "Andrew Cooper" <andrew.cooper3@xxxxxxxxxx>, Wei Liu <wl@xxxxxxx>
- Delivery-date: Wed, 12 Jan 2022 10:18:50 +0000
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- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On Wed, Jan 12, 2022 at 09:55:17AM +0100, Jan Beulich wrote:
> Looping until reaching/exceeding a certain value is error prone: If the
> target value is close enough to the wrapping point, the loop may not
> terminate at all. Switch to using delta values, which then allows to
> fold the two loops each into just one.
>
> Fixes: 93340297802b ("x86/time: calibrate TSC against platform timer")
> Reported-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
Thanks, Roger.
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