Date: Fri, 10 May 2013 08:53:57 -0400
From: Mike Snitzer <snitzer@redhat.com>
To: Joe Thornber <thornber@redhat.com>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>,
        device-mapper development <dm-devel@redhat.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] dmcache: flush superblock stats when retrieving
 status info
Message-ID: <20130510125357.GA7687@redhat.com>
References: <20130508214845.GA7729@blackbox.djwong.org>
 <20130508220526.GA24132@redhat.com>
 <20130509203616.GA5713@blackbox.djwong.org>
 <20130509204437.GA5712@blackbox.djwong.org>
 <20130510101005.GE20880@debian>
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On Fri, May 10 2013 at  6:10am -0400,
Joe Thornber <thornber@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.
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