[PATCH v8 00/11] complete deferred page initialization

[Pavel Tatashin <pasha.tatashin@oracle.com>]

Copy paste error, changing the subject for the header to v8 from v7.

On 09/14/2017 06:35 PM, Pavel Tatashin wrote:
> Changelog:
> v8 - v7
> - Added Acked-by's from Dave Miller for SPARC changes
> - Fixed a minor compiling issue on tile architecture reported by kbuild
>
> v7 - v6
> - Addressed comments from Michal Hocko
> - memblock_discard() patch was removed from this series and integrated
>    separately
> - Fixed bug reported by kbuild test robot new patch:
>    mm: zero reserved and unavailable struct pages
> - Removed patch
>    x86/mm: reserve only exiting low pages
>    As, it is not needed anymore, because of the previous fix
> - Re-wrote deferred_init_memmap(), found and fixed an existing bug, where
>    page variable is not reset when zone holes present.
> - Merged several patches together per Michal request
> - Added performance data including raw logs
>
> v6 - v5
> - Fixed ARM64 + kasan code, as reported by Ard Biesheuvel
> - Tested ARM64 code in qemu and found few more issues, that I fixed in this
>    iteration
> - Added page roundup/rounddown to x86 and arm zeroing routines to zero the
>    whole allocated range, instead of only provided address range.
> - Addressed SPARC related comment from Sam Ravnborg
> - Fixed section mismatch warnings related to memblock_discard().
>
> v5 - v4
> - Fixed build issues reported by kbuild on various configurations
>
> v4 - v3
> - Rewrote code to zero sturct pages in __init_single_page() as
>    suggested by Michal Hocko
> - Added code to handle issues related to accessing struct page
>    memory before they are initialized.
>
> v3 - v2
> - Addressed David Miller comments about one change per patch:
>      * Splited changes to platforms into 4 patches
>      * Made "do not zero vmemmap_buf" as a separate patch
>
> v2 - v1
> - Per request, added s390 to deferred "struct page" zeroing
> - Collected performance data on x86 which proofs the importance to
>    keep memset() as prefetch (see below).
>
> SMP machines can benefit from the DEFERRED_STRUCT_PAGE_INIT config option,
> which defers initializing struct pages until all cpus have been started so
> it can be done in parallel.
>
> However, this feature is sub-optimal, because the deferred page
> initialization code expects that the struct pages have already been zeroed,
> and the zeroing is done early in boot with a single thread only.  Also, we
> access that memory and set flags before struct pages are initialized. All
> of this is fixed in this patchset.
>
> In this work we do the following:
> - Never read access struct page until it was initialized
> - Never set any fields in struct pages before they are initialized
> - Zero struct page at the beginning of struct page initialization
>
>
> ==========================================================================
> Performance improvements on x86 machine with 8 nodes:
> Intel(R) Xeon(R) CPU E7-8895 v3 @ 2.60GHz and 1T of memory:
>                          TIME          SPEED UP
> base no deferred:       95.796233s
> fix no deferred:        79.978956s    19.77%
>
> base deferred:          77.254713s
> fix deferred:           55.050509s    40.34%
> ==========================================================================
> SPARC M6 3600 MHz with 15T of memory
>                          TIME          SPEED UP
> base no deferred:       358.335727s
> fix no deferred:        302.320936s   18.52%
>
> base deferred:          237.534603s
> fix deferred:           182.103003s   30.44%
> ==========================================================================
> Raw dmesg output with timestamps:
> x86 base no deferred:    https://hastebin.com/ofunepurit.scala
> x86 base deferred:       https://hastebin.com/ifazegeyas.scala
> x86 fix no deferred:     https://hastebin.com/pegocohevo.scala
> x86 fix deferred:        https://hastebin.com/ofupevikuk.scala
> sparc base no deferred:  https://hastebin.com/ibobeteken.go
> sparc base deferred:     https://hastebin.com/fariqimiyu.go
> sparc fix no deferred:   https://hastebin.com/muhegoheyi.go
> sparc fix deferred:      https://hastebin.com/xadinobutu.go
>
> Pavel Tatashin (11):
>    x86/mm: setting fields in deferred pages
>    sparc64/mm: setting fields in deferred pages
>    mm: deferred_init_memmap improvements
>    sparc64: simplify vmemmap_populate
>    mm: defining memblock_virt_alloc_try_nid_raw
>    mm: zero struct pages during initialization
>    sparc64: optimized struct page zeroing
>    mm: zero reserved and unavailable struct pages
>    x86/kasan: explicitly zero kasan shadow memory
>    arm64/kasan: explicitly zero kasan shadow memory
>    mm: stop zeroing memory during allocation in vmemmap
>
>   arch/arm64/mm/kasan_init.c          |  42 ++++++++
>   arch/sparc/include/asm/pgtable_64.h |  30 ++++++
>   arch/sparc/mm/init_64.c             |  31 +++---
>   arch/x86/mm/init_64.c               |   9 +-
>   arch/x86/mm/kasan_init_64.c         |  66 ++++++++++++
>   include/linux/bootmem.h             |  27 +++++
>   include/linux/memblock.h            |  16 +++
>   include/linux/mm.h                  |  26 +++++
>   mm/memblock.c                       |  60 +++++++++--
>   mm/page_alloc.c                     | 207 ++++++++++++++++++++----------------
>   mm/sparse-vmemmap.c                 |  15 ++-
>   mm/sparse.c                         |   6 +-
>   12 files changed, 406 insertions(+), 129 deletions(-)
>