[sheepdog] [PATCH v4 0/5] work: implement a dynamically changing thread pool

[Liu Yuan]

On 03/04/2013 08:08 AM, MORITA Kazutaka wrote:
> This removes a short thread feature, and adds a worker thread pool
> again with support of dymanic pool size.  The reasons we need this
> series are:
> 
>  - Currently, sheep calls a pthread_create for every I/O request, but
>    the overhead is not so cheap especially when the underlying disk is
>    fast (e.g. the disk has non-volatile cache).
> 
>  - Some operations (e.g. object cache pusher) consumes too many
>    threads and causes a problem.  To control the maximum number of
>    threads, a thread pool model is better for us.

I have noticed that we'll have a lot of threads remain, in my case 99,
after one installation of OS in a single VM even though there is no
active VM after that.

So I suspect that work threads shrinking isn't well functional as
expected. Do you test in a environment with massive active VMs in the
cluster and see if nr of threads of one sheep is sane?

Thanks,
Yuan