Messages in this thread | | | Date | Mon, 10 Oct 2022 09:53:42 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 6/6] x86/gsseg: use the LKGS instruction if available for load_gs_index() |
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On Mon, Oct 10, 2022 at 04:32:34AM +0000, Li, Xin3 wrote: > > > > There are not that many call sites, so using something like this > > > > (incorporating Peter Z's suggestion for the exception handler) would > > > > be better from a code readability perspective vs. a tiny increase in code size. > > > > > > The existing approach patches the binary code thus we don't need to check it > > at runtime. > > > > static_cpu_has() uses alternatives to patch the branch, so there is no runtime > > check after early boot. > > > > Sorry, didn't know it, thanks for point it out. > > If we prefer static_cpu_has, are you asking to replace all alternative macros with it?
No; the only reason to do it here would be to unconfuse that exception thing. But even there I'm not convinced.
Yes, Brian's code is much easier to read, but code-gen is quite terrible (also, my binutils can't seem to decode this -- GNU objdump (GNU Binutils for Debian) 2.38.90.20220713)
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