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Date:   Fri, 17 Aug 2018 13:28:50 +0200
From:   Heiko Carstens <heiko.carstens@de.ibm.com>
To:     David Hildenbrand <david@redhat.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Michal Hocko <mhocko@suse.com>,
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        sthemmin@microsoft.com, Pavel Tatashin <pasha.tatashin@oracle.com>,
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        Andrew Morton <akpm@linux-foundation.org>,
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Subject: Re: [PATCH RFC 1/2] drivers/base: export
 lock_device_hotplug/unlock_device_hotplug
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On Fri, Aug 17, 2018 at 01:04:58PM +0200, David Hildenbrand wrote:
> >> If there are no objections, I'll go into that direction. But I'll wait
> >> for more comments regarding the general concept first.
> > 
> > It is the middle of the merge window, and maintainers are really busy
> > right now.  I doubt you will get many review comments just yet...
> > 
> 
> This has been broken since 2015, so I guess it can wait a bit :)

I hope you figured out what needs to be locked why. Your patch description
seems to be "only" about locking order ;)

I tried to figure out and document that partially with 55adc1d05dca ("mm:
add private lock to serialize memory hotplug operations"), and that wasn't
easy to figure out. I was especially concerned about sprinkling
lock/unlock_device_hotplug() calls, which has the potential to make it the
next BKL thing.