bitbake: runqueue: fix PSI check calculation

The current PSI check calculation does not take into consideration
the possibility of the time interval between last check and current
check being much larger than 1s. In fact, the current behavior does
not match what the manual says about BB_PRESSURE_MAX_XXX, even if
the value is set to upper limit, 1000000, we still get many blocks
on new task launch. The difference between 'total' should be divided
by the time interval if it's larger than 1s.

(Bitbake rev: b4763c2c93e7494e0a27f5970c19c1aac66c228b)

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 9 insertions, 4 deletions

diff --git a/bitbake/lib/bb/runqueue.py b/bitbake/lib/bb/runqueue.py
index e629ab7e7b..02f1474540 100644
--- a/bitbake/lib/bb/runqueue.py
+++ b/bitbake/lib/bb/runqueue.py
@@ -198,15 +198,20 @@ class RunQueueScheduler(object):
                 curr_cpu_pressure = cpu_pressure_fds.readline().split()[4].split("=")[1]
                 curr_io_pressure = io_pressure_fds.readline().split()[4].split("=")[1]
                 curr_memory_pressure = memory_pressure_fds.readline().split()[4].split("=")[1]
-                exceeds_cpu_pressure =  self.rq.max_cpu_pressure and (float(curr_cpu_pressure) - float(self.prev_cpu_pressure)) > self.rq.max_cpu_pressure
-                exceeds_io_pressure =  self.rq.max_io_pressure and (float(curr_io_pressure) - float(self.prev_io_pressure)) > self.rq.max_io_pressure
-                exceeds_memory_pressure = self.rq.max_memory_pressure and (float(curr_memory_pressure) - float(self.prev_memory_pressure)) > self.rq.max_memory_pressure
                 now = time.time()
-                if now - self.prev_pressure_time > 1.0:
+                tdiff = now - self.prev_pressure_time
+                if tdiff > 1.0:
+                    exceeds_cpu_pressure =  self.rq.max_cpu_pressure and (float(curr_cpu_pressure) - float(self.prev_cpu_pressure)) / tdiff > self.rq.max_cpu_pressure
+                    exceeds_io_pressure =  self.rq.max_io_pressure and (float(curr_io_pressure) - float(self.prev_io_pressure)) / tdiff > self.rq.max_io_pressure
+                    exceeds_memory_pressure = self.rq.max_memory_pressure and (float(curr_memory_pressure) - float(self.prev_memory_pressure)) / tdiff > self.rq.max_memory_pressure
                     self.prev_cpu_pressure = curr_cpu_pressure
                     self.prev_io_pressure = curr_io_pressure
                     self.prev_memory_pressure = curr_memory_pressure
                     self.prev_pressure_time = now
+                else:
+                    exceeds_cpu_pressure =  self.rq.max_cpu_pressure and (float(curr_cpu_pressure) - float(self.prev_cpu_pressure)) > self.rq.max_cpu_pressure
+                    exceeds_io_pressure =  self.rq.max_io_pressure and (float(curr_io_pressure) - float(self.prev_io_pressure)) > self.rq.max_io_pressure
+                    exceeds_memory_pressure = self.rq.max_memory_pressure and (float(curr_memory_pressure) - float(self.prev_memory_pressure)) > self.rq.max_memory_pressure
             return (exceeds_cpu_pressure or exceeds_io_pressure or exceeds_memory_pressure)
         return False