Messages in this thread | | | Date | Tue, 23 Aug 2011 14:06:03 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [uml-devel] SYSCALL, ptrace and syscall restart breakages (Re: [RFC] weird crap with vdso on uml/i386) |
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On 08/23/2011 01:56 PM, Borislav Petkov wrote: > > But no, I don't think the difference has disappeared - to the contrary, > AFAICT, the intention is for SYSCALL to be the fastest way to do > syscalls on x86 due to diminished number of segment checks etc. INT80 > is legacy, slower, etc. I believe Andy measured a similar situation on > Sandy Bridge with SYSCALL having latencies in the tens of nsecs range > and INT80 being much slower. Ingo also measured a similar situation > where the latency gap between the two on Intel is even bigger. >
Sandy Bridge doesn't have SYSCALL32 at all. It has SYSENTER and SYSCALL64.
-hpa
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