lkml.org 
[lkml]   [2007]   [May]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] MM: implement MADV_FREE lazy freeing of anonymous memory
    Rik van Riel wrote:
    > Nick Piggin wrote:
    >
    >> Rik van Riel wrote:
    >>
    >>> With lazy freeing of anonymous pages through MADV_FREE, performance of
    >>> the MySQL sysbench workload more than doubles on my quad-core system.
    >>
    >>
    >> OK, I've run some tests on a 16 core Opteron system, both sysbench with
    >> MySQL 5.33 (set up as described in the freebsd vs linux page), and with
    >> ebizzy.
    >>
    >> What I found is that, on this system, MADV_FREE performance improvement
    >> was in the noise when you look at it on top of the MADV_DONTNEED glibc
    >> and down_read(mmap_sem) patch in sysbench.
    >
    >
    > Interesting, very different results from my system.
    >
    > First, did you run with the properly TLB batched version of
    > the MADV_FREE patch? And did you make sure that MADV_FREE
    > takes the mmap_sem for reading? Without that, I did see
    > a similar thing to what you saw...

    Yes and yes (I initially forgot to add MADV_FREE to the down_read
    case and saw horrible performance!)


    > Secondly, I'll have to try some test runs one of the larger
    > systems in the lab.
    >
    > Maybe the results from my quad core Intel system are not
    > typical; maybe the results from your 16 core Opteron are
    > not typical. Either way, I want to find out :)

    Yep. We might have something like that here, and I'll try with
    some other architectures as well next week, if I can get glibc
    built.

    --
    SUSE Labs, Novell Inc.
    -
    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: 2007-05-05 01:53    [W:0.023 / U:7.688 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site