> -----Original Message----- > From: Sean Christopherson <seanjc@xxxxxxxxxx> > Sent: Thursday, March 23, 2023 10:20 PM > To: Li,Rongqing <lirongqing@xxxxxxxxx> > Cc: pbonzini@xxxxxxxxxx; tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx; > bp@xxxxxxxxx; dave.hansen@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; > x86@xxxxxxxxxx > Subject: Re: [PATCH] KVM: x86/mmu: Don't create kvm-nx-lpage-re kthread if > not itlb_multihit > > 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 -Li
