cloud-hypervisor/vm-virtio
Rob Bradford 30b69549e1 vm-virtio: Consume pause events to prevent infinite epoll_wait calls
When a virtio device is paused an event is written to the appropriate
"pause" EventFd for the device. This will be noticed by the the device's
epoll_wait(), an atomic bool checked an if true then the thread is
parked(). When resuming the bool is reset and the thread is unpark()ed.
However the event triggering the pause is still in the EventFd so the
epoll_wait() will continue to return but because the boolean is not set
the thread will not be park()ed but instead we will busy loop around an
event that is not being consumed.

The solution is to drain the "pause" EventFd when the event is first
received and thus the epoll_wait() will only return for the pause event
once. This resolves the infinite epoll_wait() wake-ups.

Fixes: #869

Signed-off-by: Rob Bradford <robert.bradford@intel.com>
2020-03-09 19:01:38 +01:00
..
src vm-virtio: Consume pause events to prevent infinite epoll_wait calls 2020-03-09 19:01:38 +01:00
Cargo.toml build: Bump linux-loader and vm-memory dependencies 2020-03-05 11:01:30 +01:00