openssl: enable readahead and increase read buffer size (improves download speed) by edwintorok · Pull Request #17548 · curl/curl

I ran strace on curl and noticed that it is doing a lot of very short reads, of exactly 5 bytes, followed by a larger read. strace Before recvfrom(4, "\27\3\3@\30", 5, 0, NULL, NULL) = 5 ...