nginx clear static file cache without restarting

[chenmin7249]

i'm using nginx1.0.15 stable to serve static files, and with following
configurations:

    sendfile        on;
    tcp_nopush     on;
    tcp_nodelay    on;
    open_file_cache max=1048000 inactive=604800s;
    open_file_cache_min_uses 1;
    open_file_cache_valid 3600s;

here is my problem, how can i clear the static file cache without
restarting nginx without 'killall -HUP nginx'?

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,227476,227476#msg-227476