[lkml]   [2003]   [Nov]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [RFC] Simplify node/zone portion of page->flags
    Matthew Dobson <> wrote:
    > Currently we keep track of a pages node & zone in the top 8 bits (on
    > 32-bit arches, 10 bits on 64-bit arches) of page->flags. We typically
    > do: node_num * MAX_NR_ZONES + zone_num = 'nodezone'. It's non-trivial
    > to break this 'nodezone' back into node and zone numbers. This patch
    > modifies the way we compute the index to be: (node_num << ZONE_SHIFT) |
    > zone_num. This makes it trivial to recover either the node or zone
    > number with a simple bitshift. There are many places in the kernel
    > where we do things like: page_zone(page)->zone_pgdat->node_id to
    > determine the node a page belongs to. With this patch we save several
    > pointer dereferences, and it boils down to shifting some bits.

    This rather conflicts with the patch from Jesse which I have. Can you guys
    work that out and let me know when you're done?

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 13:58    [W:0.028 / U:29.244 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site