On Thu, Mar 30, 2023, Li,Rongqing wrote: > > From: Sean Christopherson <seanjc@xxxxxxxxxx> > > On Thu, Mar 23, 2023, lirongqing@xxxxxxxxx wrote: > > > From: Li RongQing <lirongqing@xxxxxxxxx> > > > > > > if CPU has not X86_BUG_ITLB_MULTIHIT bug, kvm-nx-lpage-re kthread is > > > not needed to create > > > > Unless userspace forces the mitigation to be enabled, which can be done while > > KVM is running. I agree that spinning up a kthread that is unlikely to be used is > > less than ideal, but the ~8KiB or so overhead is per-VM and not really all that > > notable, e.g. KVM's page tables easily exceed that. > > > > A thread will create lots of proc file, and slow the command, like: ps "ps" doesn't seem like a performance critical operation though. Again, I'm not completely against letting the admin opt-out entirely, but I do want sufficient justification for the extra complexity, both in the code base and in documentation.
