On 2015-04-07 08:29, Valentine Sinitsyn wrote: > On 07.04.2015 11:23, Jan Kiszka wrote: >> On 2015-04-07 08:19, Valentine Sinitsyn wrote: >>> On 07.04.2015 11:13, Jan Kiszka wrote: >>>>>> It is, at least 160 cycles with hot caches on an AMD A6-5200 APU, >>>>>> more >>>>>> towards 600 if they are colder (added some usleep to each loop in the >>>>>> test). >>>>> Great, thanks. Could you post absolute numbers, i.e how long do A >>>>> and B >>>>> take on your CPU? >>>> >>>> A is around 1910 cycles, B about 1750. >>> It's with hot caches I guess? Not bad anyways, it's a pity I didn't >>> observe this and didn't include this optimization from the day one. >> >> Yes, that is with the unmodified benchmark I sent. When I add, say >> usleep(1000) to that loop body, the cycles jumped to 4k (IIRC). >> >> BTW, this is the Jailhouse patch: >> https://github.com/siemens/jailhouse/commit/dbf2fe479ac07a677462dfa87e008e37a4e72858 >> > I guess, it's getting off-topic here, but wouldn't it be cleaner to > simply use wrmsr and rdmsr instead of vmload and vmsave in svm-vmexit.S? > This would require less changes and will keep all entry/exit setup code > in one place. It's a tradeoff between assembly lines and C statements. My feeling is that it's easier done in C, but you can prove me wrong. Jan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
