aio breaks spdy

[Richard Kearsley]

Hi
I have been tracing an issue for the past couple of days and have 
narrowed down the case to when spdy is being used with aio
Testing using a 1GB file download in chrome and firefox, http and https 
download as normal
using spdy, only the first ~250k is downloaded and then a wait of 
exactly 60 seconds between subsequent bursts of ~250k
turning 'aio off;' fixes the problem and spdy can download at the normal 
speed

I hope someone can investigate this further
Configuration details are below, if any more information is needed 
please let me know

Many thanks
Richard

FreeBSD 9.2

OpenSSL 1.0.1i 6 Aug 2014

nginx version: nginx/1.7.4 built by gcc 4.2.1 20070831 patched [FreeBSD] 
TLS SNI support enabled configure arguments: --with-debug 
--with-http_ssl_module --with-http_spdy_module --with-file-aio
also tried nginx/1.6.0

nginx.conf:

worker_processes  1;

events {
     worker_connections  1024;
}

http {
     include       mime.types;

     aio on;

     ssl_certificate     default.cer;
     ssl_certificate_key default.key;

     server {
         listen       80;
         listen 443 ssl spdy;

         location / {
             root   /data;
             index  index.html index.htm;
         }
     }
}