Re: [PATCH] x86-64: espfix for 64-bit mode *PROTOTYPE*

[Andrew Lutomirski]

On Tue, Apr 22, 2014 at 6:17 PM, H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> wrote:
> Another spin of the prototype.  This one avoids the espfix for anything
> but #GP, and avoids save/restore/saving registers... one can wonder,
> though, how much that actually matters in practice.
>
> It still does redundant SWAPGS on the slow path.  I'm not sure I
> personally care enough to optimize that, as it means some fairly
> significant restructuring of some of the code paths.  Some of that
> restructuring might actually be beneficial, but still...
>

What's the to_dmesg thing for?

It looks sane, although I haven't checked the detailed register manipulation.

Users of big systems may complain when every single CPU lines up for
that mutex.  Maybe no one cares.

--Andy
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/