lkml.org 
[lkml]   [2001]   [Nov]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] Scalable page cache

    hm, as far as i can see, your patch dirties both cachelines of the target
    struct page on every lookup (page_splay_tree_find()), correct? If correct,
    is this just an implementational thing, or something more fundamental?

    i've been thinking about getting rid of some of the cacheline dirtying in
    the page lookup code, ie. something like this:

    - #define SetPageReferenced(page) set_bit(PG_referenced, &(page)->flags)
    + #define SetPageReferenced(page) \
    + if (!test_bit(PG_referenced), &(page)->flags) \
    + set_bit(PG_referenced, &(page)->flags)

    this would have the benefit of not touching the cacheline while doing a
    simple read(), if the referenced bit is still set. (which is not cleared
    too eagerly in most no-VM-pressure cases.) And it should not be a problem
    that this is not race-free - missing to set the referenced bit is not a
    big failure.

    Ingo

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 13:13    [W:0.024 / U:117.920 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site