Hi,
I have got a problem with a celeron j1900 platform and i915 driver.
I have 3 realtime tasks that are launched sequentially.
task1 is clocked periodically at 3ms.
task1 wakes up task2 and takes 2 wakes up task 3 using priority
scheduling (and SCHED_FIFO mechanism).
everything works well, until I am using graphic applications with
activity (hide/show gui programs...,widgets creation /refresh etc).
The task1 always start periodically each 3ms, but the other threads
execution time are delayed.
I mean normally, the whole computing processing timing
(task1+task2+task3) takes normally around 800us time execution.
When I stress the graphic pages, This time becomes up to 1.6ms.
The 3 tasks are isolated on a cpu. I don't think the problem is involved
by the CPU, but more by i915 driver and memory.
I have not managed to identify the right reason with perf utility.
One thing I am sure :
if I run the same gui pages through an ssh shell, the problem has not
appeared. realtime is not "broken"
I know that the intel driver is involved.
I would need some help to identify the right problem and for finding
solutions.ideas.
Regards,
S.Ancelot
