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Date:   Tue, 2 Feb 2021 15:22:02 +0100
From:   Michal Hocko <mhocko@suse.com>
To:     David Hildenbrand <david@redhat.com>
Cc:     Mike Rapoport <rppt@kernel.org>,
        James Bottomley <jejb@linux.ibm.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Andy Lutomirski <luto@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>, Borislav Petkov <bp@alien8.de>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Christopher Lameter <cl@linux.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Elena Reshetova <elena.reshetova@intel.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
        "Kirill A. Shutemov" <kirill@shutemov.name>,
        Matthew Wilcox <willy@infradead.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Mike Rapoport <rppt@linux.ibm.com>,
        Michael Kerrisk <mtk.manpages@gmail.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
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        Shakeel Butt <shakeelb@google.com>,
        Shuah Khan <shuah@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
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        Palmer Dabbelt <palmerdabbelt@google.com>
Subject: Re: [PATCH v16 07/11] secretmem: use PMD-size pages to amortize
 direct map fragmentation
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On Tue 02-02-21 15:12:21, David Hildenbrand wrote:
[...]
> I think secretmem behaves much more like longterm GUP right now
> ("unmigratable", "lifetime controlled by user space", "cannot go on
> CMA/ZONE_MOVABLE"). I'd either want to reasonably well control/limit it or
> make it behave more like mlocked pages.

I thought I have already asked but I must have forgotten. Is there any
actual reason why the memory is not movable? Timing attacks?
-- 
Michal Hocko
SUSE Labs