Mbedtls slow handshaking

Question

I'm using mbedTLS on baremetal lwip+stm32f4 system as a Server. TLS working successfully but when I receive the Client Hello message, my receive proccess function; err = netif->input(p, netif); take a 300ms time. I need to reduce this time. How Can I do that ? This is my config file: https://wtools.io/paste-code/b7kM