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Date:   Thu, 5 Mar 2020 19:44:31 -0800
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Steven Price <steven.price@arm.com>
Cc:     linux-kernel@vger.kernel.org,
        =?ISO-8859-1?Q?J=E9r=F4me?= Glisse <jglisse@redhat.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Dan Williams <dan.j.williams@intel.com>
Subject: Re: [PATCH] mm: Correct guards for non_swap_entry()
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On Thu,  5 Mar 2020 13:05:50 +0000 Steven Price <steven.price@arm.com> wrote:

> If CONFIG_DEVICE_PRIVATE is defined, but neither CONFIG_MEMORY_FAILURE nor
> CONFIG_MIGRATION, then non_swap_entry() will return 0, meaning that the
> condition (non_swap_entry(entry) && is_device_private_entry(entry)) in
> zap_pte_range() will never be true even if the entry is a device private
> one.
> 
> Equally any other code depending on non_swap_entry() will not function
> as expected.

What are the user-visible runtime effects of this change?

Is a cc:stable needed?