From 9ea8843e14e4b13263705098da4ca6f6d658946f Mon Sep 17 00:00:00 2001
From: John Sully <john@csquare.ca>
Date: Wed, 3 Mar 2021 07:05:51 +0000
Subject: [PATCH] In low load async rehash may not complete in time, do it in
 the cron

Former-commit-id: 0a27d30753d887b6251e645abe26118068c55587
---
 src/server.cpp | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/server.cpp b/src/server.cpp
index 1bc9ab175..b1124cac9 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -2157,6 +2157,14 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
     UNUSED(id);
     UNUSED(clientData);
 
+    if (serverTL->rehashCtl != nullptr && !serverTL->rehashCtl->done) {
+        aeReleaseLock();
+        // If there is not enough lock contention we may not have made enough progress on the async
+        //  rehash.  Ensure we finish it outside the lock.
+        dictRehashSomeAsync(serverTL->rehashCtl, serverTL->rehashCtl->queue.size());
+        aeAcquireLock();
+    }
+
     /* If another threads unblocked one of our clients, and this thread has been idle
         then beforeSleep won't have a chance to process the unblocking.  So we also
         process them here in the cron job to ensure they don't starve.
@@ -2448,6 +2456,14 @@ int serverCronLite(struct aeEventLoop *eventLoop, long long id, void *clientData
     UNUSED(id);
     UNUSED(clientData);
 
+    if (serverTL->rehashCtl != nullptr && !serverTL->rehashCtl->done) {
+        aeReleaseLock();
+        // If there is not enough lock contention we may not have made enough progress on the async
+        //  rehash.  Ensure we finish it outside the lock.
+        dictRehashSomeAsync(serverTL->rehashCtl, serverTL->rehashCtl->queue.size());
+        aeAcquireLock();
+    }
+
     int iel = ielFromEventLoop(eventLoop);
     serverAssert(iel != IDX_EVENT_LOOP_MAIN);