On Thu, Apr 09, 2015 at 09:16:24AM -0400, Rik van Riel wrote:
On 04/09/2015 03:01 AM, Peter Zijlstra wrote:Well use paravirt, !paravirt stuff sucks performance wise anyhow.
On Wed, Apr 08, 2015 at 02:32:19PM -0400, Waiman Long wrote:There are some people out there running guests with dozens
For a virtual guest with the qspinlock patch, a simple unfair byte lockWho cares?
will be used if PV spinlock is not configured in or the hypervisor
isn't either KVM or Xen. The byte lock works fine with small guest
of just a few vCPUs. On a much larger guest, however, byte lock can
have serious performance problem.
of vCPUs. If the code exists to make those setups run better,
is there a good reason not to use it?
The question really is: is the added complexity worth the maintenance
burden. And I'm just not convinced !paravirt virt is a performance