From 49fd7a6e9c38c1efae4ef00193c949310feb4fd3 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Wed, 16 Nov 2022 11:11:50 +0000
Subject: [PATCH 1/2] Don't filter state in /context response

We don't filter state usually, so doing so here is a waste of time.
---
 synapse/handlers/room.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index 66a50bca6eb6..6dcfd86fdf36 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -1451,7 +1451,7 @@ async def filter_evts(events: List[EventBase]) -> List[EventBase]:
             events_before=events_before,
             event=event,
             events_after=events_after,
-            state=await filter_evts(state_events),
+            state=state_events,
             aggregations=aggregations,
             start=await token.copy_and_replace(
                 StreamKeyType.ROOM, results.start

From 97a33cd17da37fe158bf50d6c3225a50db17feeb Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Wed, 16 Nov 2022 11:16:09 +0000
Subject: [PATCH 2/2] Newsfile

---
 changelog.d/14461.misc | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/14461.misc

diff --git a/changelog.d/14461.misc b/changelog.d/14461.misc
new file mode 100644
index 000000000000..cdfa577a4c37
--- /dev/null
+++ b/changelog.d/14461.misc
@@ -0,0 +1 @@
+Improve performance of `/context` in large rooms.