lkml.org 
[lkml]   [2007]   [Sep]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [00/41] Large Blocksize Support V7 (adds memmap support)
    Date
    On Thursday 13 September 2007 23:03, David Chinner wrote:
    > On Thu, Sep 13, 2007 at 03:23:21AM +1000, Nick Piggin wrote:

    > > Well, it may not be easy to _fix_, but it's easy to try a few
    > > improvements ;)
    > >
    > > How do I make an image and run a workload that will coerce XFS into
    > > doing a significant number of vmaps?
    >
    > # mkfs.xfs -n size=16384 <dev>
    >
    > to create a filesystem with a 16k directory block size on a 4k page
    > machine.
    >
    > Then just do operations on directories with lots of files in them
    > (tens of thousands). Every directory operation will require at
    > least one vmap in this situation - e.g. a traversal will result in
    > lots and lots of blocks being read that will require vmap() for every
    > directory block read from disk and an unmap almost immediately
    > afterwards when the reference is dropped....

    Ah, wow, thanks: I can reproduce it.
    -
    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: 2007-09-13 19:45    [W:0.043 / U:1.668 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site