On Mon, Jun 04, 2012 at 10:42:00AM +0800, Liu Yuan wrote: > From: Liu Yuan <tailai.ly at taobao.com> > > For a second thought, even QEMU can issue multiple requests to the same object > we are guaranteed that those requests don't overlap on each other. Recovery > code and IO code might access the same object, but the race is excluded by epoch > so we don't need per-object lock at all for now. How are we guaranteed that? I'm pretty sure I debugged a problem with the kernel AIO code a while ago where that was not the case when using windows guests. (Using the qemu raw-posix backend, not sheepdog) |