On Tue, Sep 24 2013 at  3:19pm -0400,
Kent Overstreet [off-list ref] wrote:

On Tue, Sep 24, 2013 at 09:20:14AM -0400, Mike Snitzer wrote:

quoted

On Tue, Sep 24 2013 at  7:00am -0400,
Christoph Hellwig [off-list ref] wrote:

quoted

Just curious, what's the state of the remaining immutable bio work?

Hey Christoph,

Have you been over the patchset?  Looks sane to you?

Given how disruptive this patchset is to the block layer I'm wondering
how painful this change will be in combination with Jens' blk-mq
changes.  I'd prefer to see blk-mq before immutable biovecs; but I have
my own selfish reasons for that.

I'm also concerned about DM regressions given that a lot of DM code to
handle splitting a bio that spans target boundaries is ripped out, see:
https://patchwork.kernel.org/patch/2840657/

Oh good, you had seen that :)

Are you worried about performance regressions or actual bugs?

Actual bugs.
 

I _have_ explicitly tested that code path, but I don't know what corner
cases I may have missed so it definitely needs your eyeballs and testing
too.

As for performance - this'll be more efficient than what the dm code was
doing before. Especially when the multipage bvec patches go in.

Sure, I can appreciate that.
 

quoted

But that is just handwaving/FUD at this point cause I haven't put the
time to looking at this patchset close enough to feel comfortable.  I
can make reviewing this patchset a priority this week though.

Kent, have you rebased this patchset at all?  Do you have a git tree I
can clone to save the pain of pulling these patches out my my mbox,
etc.

Yeah: git://evilpiepirate.org/~kent/linux-bcache.git for-jens

Looking now, will build and kickoff some regression tests before I then
jump into reviewing the code.