On 08/05/2018 05:54 AM, Michael S. Tsirkin wrote: > On Fri, Aug 03, 2018 at 08:21:26PM -0500, Benjamin Herrenschmidt wrote: >> On Fri, 2018-08-03 at 22:08 +0300, Michael S. Tsirkin wrote: >>>>>> Please go through these patches and review whether this approach broadly >>>>>> makes sense. I will appreciate suggestions, inputs, comments regarding >>>>>> the patches or the approach in general. Thank you. >>>>> >>>>> Jason did some work on profiling this. Unfortunately he reports >>>>> about 4% extra overhead from this switch on x86 with no vIOMMU. >>>> >>>> The test is rather simple, just run pktgen (pktgen_sample01_simple.sh) in >>>> guest and measure PPS on tap on host. >>>> >>>> Thanks >>> >>> Could you supply host configuration involved please? >> >> I wonder how much of that could be caused by Spectre mitigations >> blowing up indirect function calls... >> >> Cheers, >> Ben. > > I won't be surprised. If yes I suggested a way to mitigate the overhead. Did we get better results (lower regression due to indirect calls) with the suggested mitigation ? Just curious. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
