On 1/14/2026 1:48 AM, Markus Armbruster wrote:
Jaehoon Kim <[email protected]> writes:
Introduce a new poll-weight parameter for aio-poll. This parameter
controls how much the most recent event interval affects the next
polling duration. When set to 0, a default value of 2 is used, meaning
the current interval contributes roughly 25% to the calculation. Larger
values decrease the weight of the current interval, enabling more
gradual adjustments to polling duration.
Signed-off-by: Jaehoon Kim <[email protected]>
[...]
diff --git a/qapi/misc.json b/qapi/misc.json
index 28c641fe2f..b21cc48a03 100644
--- a/qapi/misc.json
+++ b/qapi/misc.json
@@ -85,6 +85,11 @@
# @poll-shrink: how many ns will be removed from polling time, 0 means
# that it's not configured (since 2.9)
#
+# @poll-weight: the weight factor for adaptive polling.
+# Determines how much the current event interval contributes to
+# the next polling time calculation. 0 means that the default
+# value is used. (since 10.1)
When the default value is used, the actual value being used remains
hidden. Why?
Actually, I just followed the existing pattern of poll-grow, which also
defaults to a factor of 2 when set to 0.
It wasn't my intention to hide the value; I kept this because the
previous API has been working fine without issues.
If you think the actual value should be visible, I'll consider ways to
make it explicit in the next version.
+#
# @aio-max-batch: maximum number of requests in a batch for the AIO
# engine, 0 means that the engine will use its default (since 6.1)
#
@@ -96,6 +101,7 @@
'poll-max-ns': 'int',
'poll-grow': 'int',
'poll-shrink': 'int',
+ 'poll-weight': 'int',
'aio-max-batch': 'int' } }
##
diff --git a/qapi/qom.json b/qapi/qom.json
index 6f5c9de0f0..d90823478d 100644
--- a/qapi/qom.json
+++ b/qapi/qom.json
@@ -606,6 +606,11 @@
# algorithm detects it is spending too long polling without
# encountering events. 0 selects a default behaviour (default: 0)
#
+# @poll-weight: the weight factor for adaptive polling.
+# Determines how much the current event interval contributes to
+# the next polling time calculation. 0 selects a default
+# behaviour (default: 0) since 10.1.
This leaves the actual default behavior unspecified. Is this a good
idea?
I agree that the documentation should be more explicit.
I'll update it to clarify that the default factor is 2 and explain its
meaning.
+#
# The @aio-max-batch option is available since 6.1.
#
# Since: 2.0
@@ -614,7 +619,8 @@
'base': 'EventLoopBaseProperties',
'data': { '*poll-max-ns': 'int',
'*poll-grow': 'int',
- '*poll-shrink': 'int' } }
+ '*poll-shrink': 'int',
+ '*poll-weight': 'int' } }
##
# @MainLoopProperties:
[...]
