[lkml]   [2004]   [Mar]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [2.4] heavy-load under swap space shortage
    Andrea Arcangeli <> wrote:
    > >
    > > Having a magic knob is a weak solution: the majority of people who are
    > > affected by this problem won't know to turn it on.
    > that's why I turned it _on_ by default in my tree ;)

    So maybe Marcelo should apply this patch, and also turn it on by default.

    > There are workloads where adding anonymous pages to the lru is
    > suboptimal for both the vm (cache shrinking) and the fast path too
    > (lru_cache_add), not sure how 2.6 optimizes those bits, since with 2.6
    > you're forced to add those pages to the lru somehow and that implies
    > some form of locking.

    Basically a bunch of tweeaks:

    - Per-zone lru locks (which implicitly made them per-node)

    - Adding/removing sixteen pages for one taking of the lock.

    - Making the lock irq-safe (it had to be done for other reasons, but
    reduced contention by 30% on 4-way due to not having a CPU wander off to
    service an interrupt while holding a critical lock).

    - In page reclaim, snip 32 pages off the lru completely and drop the
    lock while we go off and process them.

    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 14:01    [W:0.020 / U:14.440 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site