[Qemu-devel] Re: [PATCH] Implement an fd pool to get real AIO with posix-aio

[Anthony Liguori]

Avi Kivity wrote:
> Anthony Liguori wrote:
>
> dup()ing the fd on each request is unnecessary work; would be better 
> to cache the duped fd.

Yeah, I was concerned about this too.  Ryan reran the fio benchmark and 
the submission latency and completion latency were identical to the 
linux-aio patches.  That suggests that the overhead of dup() is lost in 
the noise.

Since this is simpler and keeps the number of open file descriptors as 
low as possible, I was happy about that.

Regards,

Anthony Liguori

> Of course, if this is just a stepping stone, it doesn't matter very much.