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From: Nestor H. <nes...@gm...> - 2014-01-22 12:40:02
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Hi all, The x86 inline assembly cpuid instruction shows different results on for ubuntu (version 1:3.8.1-4ubuntu1 http://packages.ubuntu.com/source/saucy/valgrind) and debian (version 1:3.8.1-4+b1. http://packages.debian.org/source/testing/valgrind). It seems that in the ubuntu case it shows the info for the physical cpu, while in debian it shows the info for the emulated one by the virtual machine (an Intel Core2 Duo in this case). Is it any patches or fixes for this situation? Best regards, -- Néstor Hernández Mobile: +4551200349 |
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From: Mark W. <mj...@re...> - 2014-01-22 12:54:16
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On Wed, 2014-01-22 at 13:39 +0100, Nestor Hernandez wrote: > The x86 inline assembly cpuid instruction shows different results on for > ubuntu (version 1:3.8.1-4ubuntu1 > http://packages.ubuntu.com/source/saucy/valgrind) and debian (version > 1:3.8.1-4+b1. http://packages.debian.org/source/testing/valgrind). > > It seems that in the ubuntu case it shows the info for the physical cpu, > while in debian it shows the info for the emulated one by the virtual > machine (an Intel Core2 Duo in this case). Running the cpuid instruction under valgrind should result in info for what VEX is capable of emulating (sometimes this is less than what the physical cpu is capable of other times it is more). This is however an area that could be improved/clean up a little. So maybe there are (unknown) bugs. Do you have an concrete example where things go wrong? Maybe you could run something like http://etallen.com/cpuid.html on the physical cpu and under valgrind and show where things don't seem to match up? Thanks, Mark |