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Subject: Re: [PATCH v17 08/10] PM: hibernate: disable when there are active
 secretmem users
To:     Michal Hocko <mhocko@suse.com>
Cc:     Mike Rapoport <rppt@kernel.org>,
        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>,
        James Bottomley <jejb@linux.ibm.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>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Rick Edgecombe <rick.p.edgecombe@intel.com>,
        Roman Gushchin <guro@fb.com>,
        Shakeel Butt <shakeelb@google.com>,
        Shuah Khan <shuah@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Tycho Andersen <tycho@tycho.ws>, Will Deacon <will@kernel.org>,
        linux-api@vger.kernel.org, linux-arch@vger.kernel.org,
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        x86@kernel.org, Hagen Paul Pfeifer <hagen@jauu.net>,
        Palmer Dabbelt <palmerdabbelt@google.com>
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From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat GmbH
Message-ID: <f822a203-f7ec-8b97-b88d-1bf6bffa93d8@redhat.com>
Date:   Mon, 8 Feb 2021 14:40:42 +0100
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On 08.02.21 13:17, Michal Hocko wrote:
> On Mon 08-02-21 12:26:31, David Hildenbrand wrote:
> [...]
>> My F33 system happily hibernates to disk, even with an application that
>> succeeded in din doing an mlockall().
>>
>> And it somewhat makes sense. Even my freshly-booted, idle F33 has
>>
>> $ cat /proc/meminfo  | grep lock
>> Mlocked:            4860 kB
>>
>> So, stopping to hibernate with mlocked memory would essentially prohibit any
>> modern Linux distro to hibernate ever.
> 
> My system seems to be completely fine without mlocked memory. It would
> be interesting to see who mlocks memory on your system and check whether
> the expectated mlock semantic really works for those. This should be
> documented at least.

I checked some other installations (Ubuntu, RHEL), and they also show no 
sign of Mlock. My notebook (F33) and desktop (F33) both have mlocked 
memory. Either related to F33 or due to some software (e.g., kerberos).

-- 
Thanks,

David / dhildenb