Messages in this thread | | | From | "H.J. Lu" <> | Date | Fri, 26 Mar 2021 13:43:51 -0700 | Subject | Re: Why does glibc use AVX-512? |
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On Fri, Mar 26, 2021 at 1:35 PM Florian Weimer <fw@deneb.enyo.de> wrote:
> > All this needs to work transparently without user intervention. We > cannot require firmware upgrades to fix the incorrect RTM reporting > issue (the bug I referenced). I think we can require software updates > which tell glibc when to use RTM-enabled string functions if the > dynamic selection does not work (either for performance reasons, or > because of the RTM reporting bug). > > I want to avoid a situation where one in eight processes fail to work > correctly because the CPUID checks ran on CPU 0, where RTM is reported > as available, and then we trap when executing XTEST on other CPUs.
glibc can disable RTM based on CPU model and stepping.
-- H.J.
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