[dm-devel] [RFC PATCH 5/5] multipathd: RFC add new polling dmevents waiter thread

[Martin Wilck]

On Tue, 2018-02-13 at 10:49 -0600, Benjamin Marzinski wrote:
> On Tue, Feb 13, 2018 at 09:50:19AM +0100, Martin Wilck wrote:
> > Hi Ben,
> > 
> > Am I understanding correctly that you are working on libdevmapper
> > in
> > parallel? If yes, would it make sense to have libmultipath use the
> > newly developed libdevmapper API right away, rather than using a
> > custom-made ioctl interface until libdevmapper is ready?
> 
> I haven't been working on adding the re-arming support to
> libdevmapper.
> I just started looking into that now that I have all of these
> multipath
> patches posted.
> 
> I'm not sure I understand you suggestion. There's a large amount of
> code
> that can get executed when you call dm_task_run(). But the core bit
> of
> code that it would execute for the DM_DEV_ARM_POLL command is that
> ioctl. Also, the calculation to find the offset of the event number
> in
> the dm_names structure will be the same when libdevmapper does them.
> I
> have no problem with moving the functions I wrote (arm_dev_event_poll
> and dm_event_nr) to libmultipath/devmapper.c, where they will
> eventually
> use libdevmapper to do their work, but the actual code they will
> execute
> as part of libdevmapper will be functionally the same.

OK. I think I misunderstood your remark about libdevmapper support. 
Just go ahead according to your initial plan, fine with me.

Regards
Martin

-- 
Dr. Martin Wilck <mwilck at suse.com>, Tel. +49 (0)911 74053 2107
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