[sheepdog] [PATCH] sheep: fix oid scheduling in recovery

[Christoph Hellwig]

On Tue, Jun 05, 2012 at 07:49:07PM +0800, Liu Yuan wrote:
> On 06/05/2012 07:39 PM, Christoph Hellwig wrote:
> 
> > After running into the first coroutine problems I've not moved further
> > with testing any coroutine based qemu versions.
> 
> 
> Maybe I am not at any qualification to speak design choice of QEMU, but
> at least to me, coroutine is really a disaster (Even seems that there
> coroutine is nested), I can't even debug a simple bug if involved with
> coroutine. This bug is very reproducible and looks to me just a simple
> racy problem, but after a long time debugging with it, it just scares me
> away without any fruit. In the long run, I think coroutine based
> sheepdog block driver will risk maintainability of the code.

I completely agree with your opinion there - if you look at old list
archives you'll see that I argued against adding them to qemu but lost
the fight.  There has been some recent discussion where people advocated
for moving away from it again, though.