Google has acknowledged the memory leak Bug present in Android 5.0.1 and higher and said that the patch to fix it will be released in the upcoming updates
The memory leak bug which is present in all Android versions higher than Android 5.0.1 including the latest Android 5.1 makes your phone slower, with apps restarting or crashing on their own or a sudden drop in RAM and overall slowdown.
With the release of latest Android 5.1, the official code forum filled up with users complaining about downfall in performance after they updated to the latest version. The forum users stated that the reason the slowdown in performance was due to a old Memory leak bug which havent been patched yet.
Following the comments from Android users, finally, Google has acknowledge the bug and said that they have internally resolved the same. The users will have to wait for the fix which Google said, will be released with next patch for Android Lollipop.