[dm-devel] [PATCH 1/2] dmcache: flush superblock stats when retrieving status info

[Mike Snitzer]

On Fri, May 10 2013 at  6:10am -0400,
Joe Thornber <thornber at redhat.com> wrote:

> On Thu, May 09, 2013 at 01:44:38PM -0700, Darrick J. Wong wrote:
> > When userspace queries dmcache for stats info, we should ensure that all the
> > metadata gets flushed out of memory to disk.  The current code neglects to
> > update the disk copy of the hit/miss counters.
> 
> Nack, I'm afraid.  The commit is there purely to make sure the free
> metadata blocks reported from the status are as high as possible.
> [When a transaction is open we have to treat all blocks from the
> previous transaction as allocated to allow rollback.]

Right the commit is about presenting a more accurate status.  Darrick's
patch doesn't change what is reported for hit/miss counts (they are
reported from in-core counters already, so accuracy isn't a concern).

So I agree with what you're saying.  Thanks Joe.