SERVER-23391 Lower WiredTiger cache size floor

1 files changed, 2 insertions, 15 deletions

diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_init.cpp b/src/mongo/db/storage/wiredtiger/wiredtiger_init.cpp
index 5ccc1093549..783983aa93b 100644
--- a/src/mongo/db/storage/wiredtiger/wiredtiger_init.cpp
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_init.cpp
@@ -61,25 +61,12 @@ public:
             warning() << "Recovering data from the last clean checkpoint.";
         }
 
-        size_t cacheSizeGB = wiredTigerGlobalOptions.cacheSizeGB;
-        if (cacheSizeGB == 0) {
-            // Since the user didn't provide a cache size, choose a reasonable default value.
-            // We want to reserve 1GB for the system and binaries, but it's not bad to
-            // leave a fair amount left over for pagecache since that's compressed storage.
-            ProcessInfo pi;
-            double memSizeMB = pi.getMemSizeMB();
-            if (memSizeMB > 0) {
-                double cacheMB = (memSizeMB - 1024) * 0.6;
-                cacheSizeGB = static_cast<size_t>(cacheMB / 1024);
-                if (cacheSizeGB < 1)
-                    cacheSizeGB = 1;
-            }
-        }
+        size_t cacheMB = WiredTigerUtil::getCacheSizeMB(wiredTigerGlobalOptions.cacheSizeGB);
         const bool ephemeral = false;
         WiredTigerKVEngine* kv = new WiredTigerKVEngine(getCanonicalName().toString(),
                                                         params.dbpath,
                                                         wiredTigerGlobalOptions.engineConfig,
-                                                        cacheSizeGB,
+                                                        cacheMB,
                                                         params.dur,
                                                         ephemeral,
                                                         params.repair,