[Sheepdog] [PATCH] sheep: keep the vnodes cache until epoch changs

[Christoph Hellwig]

On Fri, Apr 27, 2012 at 03:05:46PM +0800, yaohaiting.wujue at gmail.com wrote:
> Problems:
> 
> 1, race condition
> 
> get_ordered_sd_vnode_list gets the cache and try to use it, but
> free_ordered_sd_vnode_list frees it.

So what the order by using a local variable.

> 2, no cache when I/O is not tense
> 
> create and free the cache frequently when I/O is not tense

See my "vnode mapping layer fixes and cleanups" series, which fixes this
as a side effect.