proxy_cache not writing to proxy_cache_path

[gms8994]

I've got a config file like:

http {
   proxy_cache_path /var/www/nginx/cache levels=1:2
keys_zone=tmpcache:100m;

   server {
      location ~ \.js$  {
         proxy_cache        tmpcache;
         proxy_cache_key    $uri$is_args$args;
         proxy_pass http://global;
      }
   }
}

However, I'm not seeing any data stored in the tmpcache. No folders
created, no files. What am I missing?

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,149945,149945#msg-149945