On Thu, Aug 29, 2019 at 01:37:35AM +0200, Rafael J. Wysocki wrote: > On Wed, Aug 28, 2019 at 4:39 PM Marcelo Tosatti <[email protected]> wrote: > > > > On Wed, Aug 28, 2019 at 10:45:44AM +0200, Rafael J. Wysocki wrote: > > > On Wed, Aug 28, 2019 at 10:34 AM Wanpeng Li <[email protected]> wrote: > > > > > > > > On Tue, 27 Aug 2019 at 08:43, Wanpeng Li <[email protected]> wrote: > > > > > > > > > > Cc Michael S. Tsirkin, > > > > > On Tue, 27 Aug 2019 at 04:42, Marcelo Tosatti <[email protected]> > > > > > wrote: > > > > > > > > > > > > On Tue, Aug 13, 2019 at 08:55:29AM +0800, Wanpeng Li wrote: > > > > > > > On Sun, 4 Aug 2019 at 04:21, Marcelo Tosatti > > > > > > > <[email protected]> wrote: > > > > > > > > > > > > > > > > On Thu, Aug 01, 2019 at 06:54:49PM +0200, Paolo Bonzini wrote: > > > > > > > > > On 01/08/19 18:51, Rafael J. Wysocki wrote: > > > > > > > > > > On 8/1/2019 9:06 AM, Wanpeng Li wrote: > > > > > > > > > >> From: Wanpeng Li <[email protected]> > > > > > > > > > >> > > > > > > > > > >> The downside of guest side polling is that polling is > > > > > > > > > >> performed even > > > > > > > > > >> with other runnable tasks in the host. However, even if > > > > > > > > > >> poll in kvm > > > > > > > > > >> can aware whether or not other runnable tasks in the same > > > > > > > > > >> pCPU, it > > > > > > > > > >> can still incur extra overhead in over-subscribe scenario. > > > > > > > > > >> Now we can > > > > > > > > > >> just enable guest polling when dedicated pCPUs are > > > > > > > > > >> available. > > > > > > > > > >> > > > > > > > > > >> Cc: Rafael J. Wysocki <[email protected]> > > > > > > > > > >> Cc: Paolo Bonzini <[email protected]> > > > > > > > > > >> Cc: Radim Krčmář <[email protected]> > > > > > > > > > >> Cc: Marcelo Tosatti <[email protected]> > > > > > > > > > >> Signed-off-by: Wanpeng Li <[email protected]> > > > > > > > > > > > > > > > > > > > > Paolo, Marcelo, any comments? > > > > > > > > > > > > > > > > > > Yes, it's a good idea. > > > > > > > > > > > > > > > > > > Acked-by: Paolo Bonzini <[email protected]> > > > > > > > > Hi Marcelo, > > > > > > > > If you don't have more concern, I guess Rafael can apply this patch > > > > now since the merge window is not too far. > > > > > > I will likely queue it up later today and it will go to linux-next > > > early next week. > > > > > > Thanks! > > > > NACK patch. > > I got an ACK from Paolo on it, though. Convince Paolo to withdraw his > ACK if you want it to not be applied. > > > Just don't load the haltpoll driver. > > And why would that be better?
Split the group of all kvm users in two: overcommit group and non-overcommit group. Current situation regarding haltpoll driver is: overcommit group: haltpoll driver is not loaded by default, they are happy. non overcommit group: boots without "realtime hints" flag, loads haltpoll driver, happy. Situation with patch above: overcommit group: haltpoll driver is not loaded by default, they are happy. non overcommit group: boots without "realtime hints" flag, haltpoll driver cannot be loaded.
