Messages in this thread | | | Date | Tue, 6 Mar 2007 16:25:41 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH 4/4] optimize and simplify get_cycles_sync() |
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On Wed, 28 Feb 2007 15:25:54 +0100 "Joerg Roedel" <joerg.roedel@amd.com> wrote:
> From: Joerg Roedel <joerg.roedel@amd.com> > > This patch simplifies the get_cycles_sync() function by removing the > #ifdefs from it. Further it introduces an optimization for AMD > processors. There the RDTSCP instruction is used instead of CPUID;RDTSC > which is helpfull if the kernel runs as a KVM guest. Running as a guest > makes CPUID very expensive because it causes an intercept of the guest.
Problem:
http://test.kernel.org/functional/index.html
lots of builds fell over because their binutils versions don't understand rdtscp.
I don't know how recently rdtscp support was added to binutils, but this is likely to be a problem. Perhaps we can change this patch to embed the hex code for that opcode instead? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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