Refine the DPRINTF/WPRINTF to pr_* based log interface instead of printf directly.
Tracked-On: #5267
Signed-off-by: Sun Peng <peng.p.sun@intel.com>
Reviewed-by: Chi Mingqiang <mingqiang.chi@intel.com>
Acked-by: Wang, Yu1 <yu1.wang@intel.com>
Users of pthread_cond_wait() should take care of spurious wakeups and it
is usually used in conjunction with a predicate. Not doing so can result
in unintended behavior. For example:
virtio_net_tx_thread():
entry -> pthread_cond_wait() -> spurious wakeup ->
vq_clear_used_ring_flags() -> segfault (vq->used uninitialized)
tpm_crb_request_deliver():
entry -> pthread_cond_wait() -> spurious wakeup ->
swtpm_handle_request() called needlessly
virtio_rnd_get_entropy():
entry -> pthread_cond_wait() -> spurious wakeup ->
no avail ring processing ->
virtio_rnd_notify() skips pthread_cond_signal() due to
rnd->in_progress ->
vq_endchains() called needlessly ->
wait in pthread_cond_wait() indefinitely
Fix these uses of pthread_cond_wait() by using predicates.
The only use case without a clear predicate is the tx thread in
virtio-mei, because it works with two-dimensional linked lists.
v1 -> v2:
- fix bugs and comments
- reduce code redundancy
Tracked-On: #2763
Signed-off-by: Peter Fang <peter.fang@intel.com>
Reviewed-by: Shuo A Liu <shuo.a.liu@intel.com>
Device trap has great impact on latency of real time (RT) tasks.
This patch provide a virtio poll mode to avoid trap.
According to the virtio spec, backend devices can declare the
notification is not needed so that frontend will never trap.
This means the backends make commitment to the frontends they have a
poll mechanism which don’t need any frontends notification.
This patch uses a periodic timer to give backends pseudo notifications
so that drive them processing data in their virtqueues. People should
choose a appropriate notification peroid interval to use this poll
mode. Too big interval may cause virtqueue processing latency while
too small interval may cause high SOS CPU usage. The suggested interval
is between 100us to 1ms.
The poll mode is not enabled by default and traditional trap
notification mode will be used. To use poll mode for RT with interval
1ms. You can add following acrn-dm parameter.
--virtio_poll 1000000
Tracked-On: #1956
Signed-off-by: Jie Deng <jie.deng@intel.com>
Acked-by: Yu Wang <yu1.wang@intel.com>
