On Tuesday, 12 July 2016 at 15:24:29 UTC, Guillaume Chatelet
wrote:
On Tuesday, 12 July 2016 at 13:23:46 UTC, Ilya Yaroshenko wrote:
On Tuesday, 12 July 2016 at 12:46:26 UTC, Guillaume Chatelet
wrote:
On Monday, 11 July 2016 at 16:30:44 UTC, Ilya Yaroshenko
wrote:
Hello :-)
`cpuid` package is core.cpuid analog.
It would be used by future D BLAS implementation.
Hey Ilya,
Quick question: where do the data come from/how reliable do
you think they are?
Hello Guillaume,
The data come from CPUID x86/x86_64 instruction.
I have fixed bugs for AMD yesterday. Information for Intel and
AMD processors should be reliable. But I am not sure about
Cache and TLB information for virtual machines and other
vendors. You can use cpuid.x86_any._cpuid [1] to get any
information that is not presented.
[1]
http://docs.cpuid.dlang.io/latest/cpuid_x86_any.html#._cpuid
Thx Ilya,
I was discussing this a few colleagues. I'm quoting one of them
here with his permission:
"It doesn't seems that a userland library like this has any
possibility to solve the root problem on Android/ARM. It's a
twofold problem:
1. On ARM, the registers containing CPU identification and
cache structure information, are privileged. See:
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0344f/Chdebced.html
etc... (more such registers listed in the left pane on that
page)
Thus it is up to the operating system to expose this
information to userspace. That takes us to the second part of
the problem:
2. As far as I know, Android does not expose either CPU
identification or cache structure information to userspace.
Please do correct me if I'm wrong and this library found a way
around that --- but from a cursory look at the cpuid library
code, it does not have an ARM implementation at the moment?"
Thank you for the information, I have not know that registers are
privileged on ARM! By "other vendors" I mean other x86 vendors
listed in enum VendorIndex [1]. ARM is not supported, but API
supports complex topology. So ARM direction is to receive
approximate information from an OS, like from /proc/cpuinfo on
Linux. Just CPU brand name with version is significant
information for cache size.
[1]
http://docs.cpuid.dlang.io/latest/cpuid_x86_any.html#.VendorIndex
