Re: [PATCHv7 00/29] THP-enabled tmpfs/shmem using compound pages

From	Andres Lagar-Cavilla <andreslc@google.com>
Newsgroups	linux.kernel
Subject	Re: [PATCHv7 00/29] THP-enabled tmpfs/shmem using compound pages
Date	2016-04-25 15:40 +0200
Message-ID	<rrOU2-6G6-25@gated-at.bofh.it> (permalink)
References	<romhz-3cc-3@gated-at.bofh.it> <rpqj8-52L-15@gated-at.bofh.it> <rpHai-1sn-23@gated-at.bofh.it> <rpHjY-1Nv-17@gated-at.bofh.it> <rrl5D-7U4-3@gated-at.bofh.it>
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On Sat, Apr 23, 2016 at 10:46 PM, Wincy Van <fanwenyi0529@gmail.com> wrote:
> On Wed, Apr 20, 2016 at 1:07 AM, Andres Lagar-Cavilla
> <andreslc@google.com> wrote:
>> Andrea, we provide the, ahem, adjustments to
>> transparent_hugepage_adjust. Rest assured we aggressively use mmu
>> notifiers with no further changes required.
>>
>> As in: zero changes have been required in the lifetime (years) of
>> kvm+huge tmpfs at Google, other than mod'ing
>> transparent_hugepage_adjust.
>
> We are using kvm + tmpfs to do qemu live upgrading, how does google
> use this memory model ?
> I think our pupose to use tmpfs may be the same.

Nothing our of the ordinary. Guest memory is an mmap of a tmpfs fd.
Huge tmpfs gives us naturally a great guest performance boost.
MAP_SHARED, and having guest memory persist any one given process, are
what drives us to use tmpfs.

Andres
>
> And huge tmpfs is a really good improvement for that.
>
>>
>> As noted by Paolo, the additions to transparent_hugepage_adjust could
>> be lifted outside of kvm (into shmem.c? maybe) for any consumer of
>> huge tmpfs with mmu notifiers.
>>
>
> Thanks,
> Wincy



-- 
Andres Lagar-Cavilla | Google Kernel Team | andreslc@google.com

Thread

[PATCHv7 00/29] THP-enabled tmpfs/shmem using compound pages "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-04-16 02:40 +0200
  [PATCHv7 07/29] thp, vmstats: add counters for huge file pages "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-04-16 02:40 +0200
  [PATCHv7 14/29] thp: file pages support for split_huge_page() "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-04-16 02:40 +0200
  Re: [PATCHv7 00/29] THP-enabled tmpfs/shmem using compound pages "Shi, Yang" <yang.shi@linaro.org> - 2016-04-19 01:00 +0200
    Re: [PATCHv7 00/29] THP-enabled tmpfs/shmem using compound pages Jerome Marchand <jmarchan@redhat.com> - 2016-04-19 16:40 +0200
      Re: [PATCHv7 00/29] THP-enabled tmpfs/shmem using compound pages "Shi, Yang" <yang.shi@linaro.org> - 2016-04-19 18:20 +0200
    Re: [PATCHv7 00/29] THP-enabled tmpfs/shmem using compound pages Andrea Arcangeli <aarcange@redhat.com> - 2016-04-19 19:00 +0200
      Re: [PATCHv7 00/29] THP-enabled tmpfs/shmem using compound pages Andres Lagar-Cavilla <andreslc@google.com> - 2016-04-19 19:10 +0200
        Re: [PATCHv7 00/29] THP-enabled tmpfs/shmem using compound pages Wincy Van <fanwenyi0529@gmail.com> - 2016-04-24 07:50 +0200
          Re: [PATCHv7 00/29] THP-enabled tmpfs/shmem using compound pages Andres Lagar-Cavilla <andreslc@google.com> - 2016-04-25 15:40 +0200
            Re: [PATCHv7 00/29] THP-enabled tmpfs/shmem using compound pages Wincy Van <fanwenyi0529@gmail.com> - 2016-04-26 16:10 +0200
        Re: [PATCHv7 00/29] THP-enabled tmpfs/shmem using compound pages Andrea Arcangeli <aarcange@redhat.com> - 2016-04-27 17:50 +0200
      Re: [PATCHv7 00/29] THP-enabled tmpfs/shmem using compound pages "Shi, Yang" <yang.shi@linaro.org> - 2016-04-20 01:50 +0200
    Re: [PATCHv7 00/29] THP-enabled tmpfs/shmem using compound pages Hugh Dickins <hughd@google.com> - 2016-04-20 10:40 +0200

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