Messages in this thread | | | Date | Wed, 5 Nov 2008 21:15:58 +0300 | From | Cyrill Gorcunov <> | Subject | Re: [PATCH RFC/RFB] x86_64, i386: interrupt dispatch changes |
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[Andi Kleen - Tue, Nov 04, 2008 at 06:05:01PM +0100] | > not taking into account the cost of cs reading (which I | > don't suspect to be that expensive apart from writting, | | GDT accesses have an implied LOCK prefix. Especially | on some older CPUs that could be slow. | | I don't know if it's a problem or not but it would need | some careful benchmarking on different systems to make sure interrupt | latencies are not impacted. | | Another reason I would be also careful with this patch is that | it will likely trigger slow paths in JITs like qemu/vmware/etc. | | Also code segment switching is likely not something that | current and future micro architectures will spend a lot of time optimizing. | | I'm not sure that risk is worth the small improvement in code | size. | | An alternative BTW to having all the stubs in the executable | would be to just dynamically generate them when the interrupt | is set up. Then you would only have the stubs around for the | interrupts which are actually used. | | -Andi |
Thanks a lot for comments, Andi!
- Cyrill -
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