diff mbox series

[2.0,3/5] runqueue.py: fix PSI check logic

Message ID 20231110135437.2902924-3-martin.jansa@gmail.com
State Accepted, archived
Commit 76889ff0a8938a3d77603d2af176aa9e264df839
Headers show
Series [2.0,1/5] runqueue: fix PSI check calculation | expand

Commit Message

Martin Jansa Nov. 10, 2023, 1:54 p.m. UTC 
From: Chen Qi <Qi.Chen@windriver.com>

The current calculation is not correct because if tdiff is less than
1.0, it's not taken into consideration when calculating the current
pressure.

Also, make it clear that the 1.0s is the psi accumulation cycle,
which might be changed in the future. We have this cycle because it
could largely avoid the 0 result issue, that is, if the interval
between checks are too small, the result might be 0. With this
accumulation logic, which has been there but let's make it clear,
this 0 result problem could be mitigated.

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
---
 lib/bb/runqueue.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/lib/bb/runqueue.py b/lib/bb/runqueue.py
index ab9e3fbe8..830af8eef 100644
--- a/lib/bb/runqueue.py
+++ b/lib/bb/runqueue.py
@@ -200,7 +200,8 @@  class RunQueueScheduler(object):
                 curr_memory_pressure = memory_pressure_fds.readline().split()[4].split("=")[1]
                 now = time.time()
                 tdiff = now - self.prev_pressure_time
-                if tdiff > 1.0:
+                psi_accumulation_interval = 1.0
+                if tdiff > psi_accumulation_interval:
                     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
@@ -209,9 +210,9 @@  class RunQueueScheduler(object):
                     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
+                    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
             pressure_state = (exceeds_cpu_pressure, exceeds_io_pressure, exceeds_memory_pressure)
             if hasattr(self, "pressure_state") and pressure_state != self.pressure_state:
                 bb.note("Pressure status changed to CPU: %s, IO: %s, Mem: %s" % pressure_state)