diff --git a/synapse/metrics/__init__.py b/synapse/metrics/__init__.py
index 31b7b3c256..e671da26d5 100644
--- a/synapse/metrics/__init__.py
+++ b/synapse/metrics/__init__.py
@@ -535,6 +535,13 @@ class ReactorLastSeenMetric:
REGISTRY.register(ReactorLastSeenMetric())
+# The minimum time in seconds between GCs for each generation, regardless of the current GC
+# thresholds and counts.
+MIN_TIME_BETWEEN_GCS = (1.0, 10.0, 30.0)
+
+# The time (in seconds since the epoch) of the last time we did a GC for each generation.
+_last_gc = [0.0, 0.0, 0.0]
+
def runUntilCurrentTimer(reactor, func):
@functools.wraps(func)
@@ -575,11 +582,16 @@ def runUntilCurrentTimer(reactor, func):
return ret
# Check if we need to do a manual GC (since its been disabled), and do
- # one if necessary.
+ # one if necessary. Note we go in reverse order as e.g. a gen 1 GC may
+ # promote an object into gen 2, and we don't want to handle the same
+ # object multiple times.
threshold = gc.get_threshold()
counts = gc.get_count()
for i in (2, 1, 0):
- if threshold[i] < counts[i]:
+ # We check if we need to do one based on a straightforward
+ # comparison between the threshold and count. We also do an extra
+ # check to make sure that we don't a GC too often.
+ if threshold[i] < counts[i] and MIN_TIME_BETWEEN_GCS[i] < end - _last_gc[i]:
if i == 0:
logger.debug("Collecting gc %d", i)
else:
@@ -589,6 +601,8 @@ def runUntilCurrentTimer(reactor, func):
unreachable = gc.collect(i)
end = time.time()
+ _last_gc[i] = end
+
gc_time.labels(i).observe(end - start)
gc_unreachable.labels(i).set(unreachable)
|
