again async io

[Igor Sysoev]

On Wed, 22 Nov 2006, Aleksandar Lazic wrote:

> I have read some docs and some papers and have changed my opinion about
> the asyncIO.
>
> Personally I think it could help to improve the performance, but I
> haven't the glue, yet, to add it into the nginx.

Last entries about AIO in http://blog.lighttpd.net/ show perfomance
improvements. However,

1) Tests were made against single process lighttpd, but not
    multi-process mode.

2) Whether some improvement will be for 1000 parallel downloads.

3) libaio requires linking with -lpthread, so it's seems it's not
    a true AIO implemenation but emulation using threads.

4) I'm not sure that /dev/shm|mmap|libaio|sendfile combination will be
    stable interface.  For example, epoll had several interface changes.


Igor Sysoev
http://sysoev.ru/en/