Re: Intel microcode update and glibc HLE

[Siddhesh Poyarekar <siddhesh at redhat dot com>]

On Fri, Sep 26, 2014 at 02:28:13PM -0400, Josh Boyer wrote:
> I was under the impression that the glibc implementation was looking
> at the cpuid registers directly for the HLE/RTM support.  If it was
> looking at cpuflags then the kernel could have probably hidden this
> with a quirk.

It looks at the cpuid registers directly.

> I'll be updating the Fedora kernel and dracut to do early microcode
> loading today.  Kyle McMartin looked at the suspend/hibernate-resume
> paths and things should work fine with early microcode loading.

That's great.

> Disabling this in glibc on x86 seems fine since nothing will be
> capable of using it until newer CPUs are released, but it wasn't
> strictly necessary.

I wasn't aware of the plan to do the early microcode loading, which is
why we went with disabling HLE.  It's really just a flip of a
configure flag and rebuild, so we can even revert it and test once the
kernel bits are in.

Siddhesh

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