On 02/06/2012 09:11 PM, Anthony Liguori wrote:
I'm not so sure. ioeventfds and a future mmio-over-socketpair have to
put the kthread to sleep while it waits for the other end to process
it. This is effectively equivalent to a heavy weight exit. The
difference in cost is dropping to userspace which is really neglible
these days (< 100 cycles).
On what machine did you measure these wonderful numbers?
But I agree a heavyweight exit is probably faster than a double context
switch on a remote core.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
