1 files changed, 6 insertions, 1 deletions
diff --git a/src/config.c b/src/config.c
index 768db1e9a..a36eb9a39 100644
--- a/src/config.c
+++ b/src/config.c
@@ -438,7 +438,12 @@ void configSetCommand(redisClient *c) {
         if (getLongLongFromObject(o,&ll) == REDIS_ERR ||
             ll < 0) goto badfmt;
         server.maxmemory = ll;
-        if (server.maxmemory) freeMemoryIfNeeded();
+        if (server.maxmemory) {
+            if (server.maxmemory < zmalloc_used_memory()) {
+                redisLog(REDIS_WARNING,"WARNING: the new maxmemory value set via CONFIG SET is smaller than the current memory usage. This will result in keys eviction and/or inability to accept new write commands depending on the maxmemory-policy.");
+            }
+            freeMemoryIfNeeded();
+        }
     } else if (!strcasecmp(c->argv[2]->ptr,"maxmemory-policy")) {
         if (!strcasecmp(o->ptr,"volatile-lru")) {
             server.maxmemory_policy = REDIS_MAXMEMORY_VOLATILE_LRU;