[dm-devel] [LSF/MM ATTEND] discuss blk-mq related to DM-multipath and status of XCOPY

[Mike Snitzer]

Hi,

I'd like to attend LSF (and the first day of Vault).

As a DM maintainer I'm open to discussing anything DM related.  In
particular I'd like to at least have hallway track discussions with
key people interested in DM multipath support for blk-mq devices.
Keith Busch and I have gone ahead and implemented the bulk of this
request-based DM support for blk-mq devices, see:
https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/log/?h=dm-for-3.20-blk-mq

But Bart says he is seeing inconsistent performance now that the code
appears relatively stable.  I'll continue analyzing this aspect of
things and by the time LSF rolls around I hope the code to be sorted.

Another topic we need to come to terms with is the state of XCOPY
(whether the initial approach needs further work, etc) -- Mikulas
Patocka reworked aspects of Martin's initial approach but it hasn't
progressed upstream:
https://www.redhat.com/archives/dm-devel/2014-October/msg00167.html