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    SubjectRe: [PATCH 02/22] Do not sanity check order in the fast path
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    On Wed, 2009-04-22 at 18:34 -0700, Dave Hansen wrote:
    > I'll also go and see what the actual .text size
    > changes are from this patch both for alloc_pages() and
    > alloc_pages_node() separately to make sure what we're dealing with
    > here. Does this check even *exist* in the optimized code very
    > often?

    While this isn't definitive by any means, I did get some interesting
    results. Pulling the check out of alloc_pages() had no effect at *all*
    on text size because I'm trying with CONFIG_NUMA=n.

    $ size i386-T41-laptop.{0,1}/vmlinux
    text data bss dec hex filename
    4348625 286560 860160 5495345 53da31 i386-T41-laptop.0/vmlinux
    4348625 286560 860160 5495345 53da31 i386-T41-laptop.1/vmlinux

    We get a slightly different when pulling the check out of
    alloc_pages_node():

    $ size i386-T41-laptop.{1,2}/vmlinux
    text data bss dec hex filename
    4348625 286560 860160 5495345 53da31 i386-T41-laptop.1/vmlinux
    4348601 286560 860160 5495321 53da19 i386-T41-laptop.2/vmlinux

    $ bloat-o-meter i386-T41-laptop.1/vmlinux i386-T41-laptop.2/vmlinux
    add/remove: 0/0 grow/shrink: 9/7 up/down: 78/-107 (-29)
    function old new delta
    __get_user_pages 717 751 +34
    st_read 1936 1944 +8
    shmem_truncate_range 1660 1667 +7
    pci_create_slot 410 417 +7
    sg_build_indirect 449 455 +6
    n_tty_read 1336 1342 +6
    find_vma_prepare 103 108 +5
    as_update_iohist 617 621 +4
    ntfs_readdir 3426 3427 +1
    enlarge_buffer 343 341 -2
    __get_free_pages 36 33 -3
    dma_generic_alloc_coherent 207 202 -5
    mempool_alloc_pages 33 17 -16
    futex_lock_pi 2120 2104 -16
    kallsyms_lookup_name 102 82 -20
    cache_alloc_refill 1171 1126 -45

    I'm going to retry this with a NUMA config.

    -- Dave



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