On Thu, Apr 4, 2024 at 11:17 AM Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > On Thu, Apr 04, 2024, David Matlack wrote: > > > I don't love the idea of adding more arch specific MMU behavior (going the wrong > > > direction), but it doesn't seem like an unreasonable approach in this case. > > > > I wonder if this is being overly cautious. > > Probably. "Lazy" is another word for it ;-) > > > I would expect only more benefit on architectures that more aggressively take > > the mmu_lock on vCPU threads during faults. The more lock acquisition on vCPU > > threads, the more this patch will help reduce vCPU starvation during > > CLEAR_DIRTY_LOG. > > > > Hm, perhaps testing with ept=N (which will use the write-lock for even > > dirty logging faults) would be a way to increase confidence in the > > effect on other architectures? > > Turning off the TDP MMU would be more representative, just manually disable the > fast-path, e.g. Good idea. I'm actually throwing in some writable module parameters too to make it easy to toggle between configurations. I'll report back when I have some data.
