This fixes an issue for missing HW events when out of HW events.
We cannot determine whether a HW event has occurred unless we call the
underlying drivers with hsaKmtWaitOnMultipleEvents_Ext. Previous logic
in Signal::WaitAny would switch to ACTIVE_WAIT state if we run out of
hardware events (signal->EopEvent() == NULL) and this would cause the
hsaKmtWaitOnMultipleEvents_Ext call to be skipped. But also, when we
have some signals without hardware events, calling
hsaKmtWaitOnMultipleEvents_Ext with a timeout of 0 so that we can poll
for remaining signals adds overhead with an IOCTL call and may cause
extra delay. Separating AsyncEventLoop into two separate threads so
that:
1. We can have a new Signal::WaitAnyExceptions to wait for HW events
This function can be simpler as it does not have to perform all the
timer calculations because it is expected to be always waiting on
hsaKmtWaitOnMultipleEvents_Ext through the lifetime of a process.
2. Signal::WaitAny does not need to have extra code to check for HW
exceptions as it only needs to handle HSA_EVENTTYPE_SIGNAL events. It
can also skip the calls to hsaKmtWaitOnMultipleEvents_Ext if needed.
Change-Id: I52ba99fd6e483e0cb477b7931a0dcc03520aa523
Signed-off-by: David Yat Sin <David.YatSin@amd.com>
David Yat Sin
88eaa834d0