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Date: Mon, 6 Nov 2017 13:12:22 +0100
From: Michal Hocko <mhocko@kernel.org>
Subject: Re: [PATCH] mm: use in_atomic() in print_vma_addr()
Message-ID: <20171106121222.nnzrr4cb7s7y5h74@dhcp22.suse.cz>
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To: Peter Zijlstra <peterz@infradead.org>
Cc: Bart Van Assche <Bart.VanAssche@wdc.com>, "yang.s@alibaba-inc.com" <yang.s@alibaba-inc.com>, "akpm@linux-foundation.org" <akpm@linux-foundation.org>, "joe@perches.com" <joe@perches.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "linux-mm@kvack.org" <linux-mm@kvack.org>, "mingo@redhat.com" <mingo@redhat.com>

On Mon 06-11-17 13:00:25, Peter Zijlstra wrote:
> On Mon, Nov 06, 2017 at 11:43:54AM +0100, Michal Hocko wrote:
> > > Yes the comment is very much accurate.
> > 
> > Which suggests that print_vma_addr might be problematic, right?
> > Shouldn't we do trylock on mmap_sem instead?
> 
> Yes that's complete rubbish. trylock will get spurious failures to print
> when the lock is contended.

Yes, but I guess that it is acceptable to to not print the state under
that condition.
-- 
Michal Hocko
SUSE Labs

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