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Subject: Re: [PATCH RFC] mm/madvise: introduce MADV_POPULATE to
 prefault/prealloc memory
To:     Michal Hocko <mhocko@suse.com>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Andrew Morton <akpm@linux-foundation.org>,
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        "Michael S . Tsirkin" <mst@redhat.com>,
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        linux-xtensa@linux-xtensa.org, linux-arch@vger.kernel.org
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From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat GmbH
Message-ID: <3b5cd68d-c4ac-c6be-8824-34c541d5377b@redhat.com>
Date:   Mon, 22 Feb 2021 14:22:37 +0100
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>> Exactly. But for hugetlbfs/shmem ("!RAM-backed files") this is not what we
>> want.
> 
> OK, then I must have misread your requirements. Maybe I just got lost in
> all the combinations you have listed.

Another special case could be dax/pmem I think. You might want to fault 
it in readable/writable but not perform an actual read/write unless 
really required.

QEMU phrases this as "don't cause wear on the storage backing".

-- 
Thanks,

David / dhildenb