Messages in this thread | | | Date | Tue, 30 Jan 2018 07:56:53 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH v5 04/12] x86: introduce __uaccess_begin_nospec and ifence |
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* Dan Williams <dan.j.williams@intel.com> wrote:
> > The flip side is that if the MFENCE stalls the STAC that is ahead of it could be > > processed for 'free' - while it's always post barrier with my suggestion. > > This 'for free' aspect is what I aiming for.
Ok.
> > > > But in any case it would be nice to see a discussion of this aspect in the > > changelog, even if the patch does not change. > > I'll add a note to the changelog that having the fence after the > 'stac' hopefully allows some overlap of the cost of 'stac' and the > flushing of the instruction pipeline.
Perfect!
Thanks,
Ingo
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