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Date: Tue, 31 Oct 2017 16:25:32 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Michal Hocko <mhocko@kernel.org>
Cc: Byungchul Park <byungchul.park@lge.com>,
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        Thomas Gleixner <tglx@linutronix.de>, Vlastimil Babka <vbabka@suse.cz>,
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Subject: Re: possible deadlock in lru_add_drain_all
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On Tue, Oct 31, 2017 at 02:13:33PM +0100, Michal Hocko wrote:

> > I can indeed confirm it's running old code; cpuhp_state is no more.
> 
> Does this mean the below chain is no longer possible with the current
> linux-next (tip)?

I see I failed to answer this; no it will happen but now reads like:

	s/cpuhp_state/&_up/

Where we used to have a single lock protecting the hotplug stuff, we now
have 2, one for bringing stuff up and one for tearing it down.

This got rid of lock cycles that included cpu-up and cpu-down parts;
those are false positives because we cannot do cpu-up and cpu-down
concurrently.

But this report only includes a single (cpu-up) part and therefore is
not affected by that change other than a lock name changing.