[dm-devel] Bcache upstreaming

[Kent Overstreet]

On Thu, Jan 10, 2013 at 10:14:24AM -0800, Kent Overstreet wrote:
> On Thu, Jan 10, 2013 at 11:47:04AM -0500, Mike Snitzer wrote:
> > On Wed, Jan 09 2013 at 11:12am -0500,
> > Mike Snitzer <snitzer at redhat.com> wrote:
> > 
> > > (take3 with feeling.. I reverted to the gmail's old compose so all
> > > should be right in my plain-text gmail world... apologies to Kent and
> > > dm-devel for the redundant messages)
> > > 
> > > Hey Kent,
> > > 
> > > On Fri, Jan 4, 2013 at 6:50 PM, Kent Overstreet <koverstreet at google.com> wrote:
> > > > I've (finally!) got a bcache branch hacked up that ought to be suitable
> > > > to go upstream, possibly in staging initially.
> > > >
> > > > It's currently closer to the dev branch than the stable branch, plus
> > > > some additional minor changes to make it all more self contained. The
> > > > code has seen a decent amount of testing and I think it's in good shape,
> > > > but I'd like it if it could see a bit more testing before I see about
> > > > pushing it upstream.
> > > >
> > > > If anyone wants to try it out, checkout the bcache-for-staging branch.
> > > > It's against Linux 3.7.
> > > 
> > > I pulled your 'bcache-for-staging' code into a 'dm-devel-cache-bcache'
> > > branch on my github:
> > > https://github.com/snitm/linux
> > > 
> > > Purpose is to have a single kernel to compare dm-cache and bcache.  My
> > > branch is against 3.8-rc2.  While importing your code I needed the
> > > following change to get bcache to compile:
> > > https://github.com/snitm/linux/commit/400b1257e93975864fd6c4b827537a0234551253
> > > 
> > > It now builds without issue but I haven't tested the resulting bcache
> > 
> > Just tried to use bcache at it locked up:
> 
> Interesting, this is a new bug...
> 
> The main bcache branch is also on top of 3.7, and it doesn't have this
> new allocation code and should be fine if you want to try that (there
> were also a few bugs I fixed in the master branch without updating the
> staging branch, but this looks like something new).
> 
> Gonna try and reproduce this, after I fix that sysfs code. Hrm.

Fyi, this is fixed (missed it because my test scripts were using cache
replacement policy = random, to better stress other stuff. Doh.)