OpenAFS Master Repository branch, master, updated. BP--openafs-stable-1_6_x-499-g4a2d197

[Gerrit Code Review]

The following commit has been merged in the master branch:
commit 4a2d1973fc5c2aac05beef5d64e7a486757c54af
Author: Marc Dionne <marc.c.dionne@gmail.com>
Date:   Tue Nov 23 19:08:24 2010 -0500

    Cache bypass: switch to rx_Readv
    
    Tests show that cache bypass doesn't scale very well past a few
    concurrent processes, with a lot of lock contention in the RX
    layer.  Switching the implementation to the iovec based rx_Readv
    alleviates much of this.
    
    Also take advantage of the fact that the upper layer readpages
    only sends down contiguous lists of pages, and issue larger read
    requests and populate the pagecache pages from the iovecs we
    get back.  The loop logic is changed significantly to accomodate
    the new pattern.
    
    Read throughput is improved by about 30-40% for some parallel read
    benchmarks I use.  Along with some other tweaks, it can allow the
    throughput to be more than doubled.
    
    Change-Id: I56877ec15eba035429bd4ea32731687c862f151f
    Reviewed-on: http://gerrit.openafs.org/3375
    Tested-by: BuildBot <buildbot@rampaginggeek.com>
    Reviewed-by: Derrick Brashear <shadow@dementia.org>

 src/afs/afs_bypasscache.c |  106 ++++++++++++++++++++++++--------------------
 1 files changed, 58 insertions(+), 48 deletions(-)

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OpenAFS Master Repository