On Thu, 30 Jan 2020 09:41:08 -0800 Michael Hinton <[email protected]> wrote:
> On Monday, January 27, 2020 at 12:16:08 AM UTC-7, Henning Schild > wrote: > > > > Ok, so we are just looking for differences between the inmate and > > the linux as non-root cell, because the jailhouse/virtualization > > overhead is acceptable or known. > > > I think so, yeah. > > > > In that case a memory bound workload boils down to the mapping and > > the tlb misses or CAT. And cpu bound could be an issue with the > > FPU. If your binary uses FPU instructions but is able to fall back > > to soft-fpu, you should check which path it takes in the inmate. > > > Let's see: CAT isn't supported by my chip, so that won't help, > unfortunately. But the Linux workload is mostly idle, so I'm not sure > how much that would have helped anyways. > > My inmates don't use FPU instructions, and it's not even set up, so I > don't think that will cause a problem. > > I will investigate TLB misses and page mappings and see what I can > find. To align the mapping on the hypervisor side, you could just run that inmate in the same cell configuration you are running that guest-linux in. For the inmate itself the pagetable is constructed by the mapping library. The code looks like it tries to do huge pages, make sure the call map_range just once with your full memory range. Aligned and maybe more than you actually need. Consider putting a few printfs into the mapping code to see which path (page-size) it goes. That way you might get lucky without having to find how to read tlb-miss counters from the inmate. Henning > Thanks, > Michael > -- You received this message because you are subscribed to the Google Groups "Jailhouse" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/jailhouse-dev/20200131100917.3ad1b337%40md1za8fc.ad001.siemens.net.
