Add performance issues(moby/moby#17720, moby/moby#19328)

README.md

@@ -100,4 +100,10 @@ Links:
 |Issue|Abstract|Impact|Reproducibility|Cause|Solution|Notes|
 |---|---|---|---|---|---|---|
 |:white_large_square: [#5684](https://github.com/docker/docker/issues/5684)|Cannot restart containers after restaring the daemon|:scream: High|:scream: Hard|Unanalyzed|None||
+|:white_large_square: [#17720](https://github.com/docker/docker/issues/17720)|Docker daemon 1.9 serious performance issue|:scream: High|:scream: high|?|Use Docker 1.10||
 |:white_large_square: [#20670](https://github.com/docker/docker/issues/20670)|/dev/pts unmounted on the HOST when you are using `-v /dev:/dev` (After that you can no longer open SSH nor xterm)|:scream: High|:smiley: Easy|daemon bug related to mount namespace|Spawn the docker daemon from systemd. Or do not use `-v /dev:/dev`||
+|:white_large_square: [#20670](https://github.com/docker/docker/issues/20670)|/dev/pts unmounted on the HOST when you are using `-v /dev:/dev` (After that you can no longer open SSH nor xterm)|:scream: High|:smiley: Easy|daemon bug related to mount namespace|Spawn the docker daemon from systemd. Or do not use `-v /dev:/dev`||
+
+
+Non-bug issues:
+ * `docker ps` is sometimes slow due to lock: [#19328](https://github.com/docker/docker/issues/19328)