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Re: [PATCH v4 2/3] x86/time: yield to hyperthreads after updating TSC during rendezvous
- To: Jan Beulich <jbeulich@xxxxxxxx>
- From: Roger Pau Monné <roger.pau@xxxxxxxxxx>
- Date: Tue, 20 Apr 2021 17:59:00 +0200
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- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On Thu, Apr 01, 2021 at 11:54:27AM +0200, Jan Beulich wrote:
> Since we'd like the updates to be done as synchronously as possible,
> make an attempt at yielding immediately after the TSC write.
>
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
Did you observe any difference with the pause inserted?
I wonder whether that's enough to give a chance the hyperthread to
also perform the TSC write. In any case there's no harm from it
certainly.
Thanks, Roger.
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