lkml.org 
[lkml]   [2019]   [Jun]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v3 0/3] KVM: Yield to IPI target if necessary
2019-05-30 09:05+0800, Wanpeng Li:
> The idea is from Xen, when sending a call-function IPI-many to vCPUs,
> yield if any of the IPI target vCPUs was preempted. 17% performance
> increasement of ebizzy benchmark can be observed in an over-subscribe
> environment. (w/ kvm-pv-tlb disabled, testing TLB flush call-function
> IPI-many since call-function is not easy to be trigged by userspace
> workload).

Have you checked if we could gain performance by having the yield as an
extension to our PV IPI call?

It would allow us to skip the VM entry/exit overhead on the caller.
(The benefit of that might be negligible and it also poses a
complication when splitting the target mask into several PV IPI
hypercalls.)

Thanks.

\
 
 \ /
  Last update: 2019-06-10 16:35    [W:0.091 / U:1.500 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site