Messages in this thread | | | Date | Fri, 23 May 2008 11:09:28 -0700 | From | Suresh Siddha <> | Subject | Re: [RFC] x86: xsave/xrstor support, ucontext_t extensions |
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On Thu, May 22, 2008 at 07:49:18PM -0700, H. Peter Anvin wrote: > Roland McGrath wrote: > >>hmm.. so the kernel needs to export all the cpuid info (that the kernel > >>enables and supports) to the user through some mechanism then? > > > >For a cheap interface, we use AT_HWCAP for this. Unfortunately that only > >covers the first 32 bits of CPUID info. (For another cheap interface, > >giving all the CPUID bits in the vDSO would be easy.) > > > >For a clunky interface that already exists and is "simple" to use, > >there is /dev/cpu/0/cpuid now. I wonder if having a device node and > >opening it too much for applications that consider the vDSO too complex. > > I doubt it.
Ok. If really needed, they can use this interface aswell. But I don't see a need for a new system call / other mechanism, just for xsave purpose. They can rely on cpuid or any other equivalent infrastructure the kernel provides.
thanks, suresh
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