Open Stack

Hi, I'd like you to take a look at this patch for potential
documentation impact.
https://review.openstack.org/15704

Log:
commit 6040e89cc9ff8ec49d566c5a78bf1931c2813ca4
Author: Chris Behrens <cbehrens at codestud.com>
Date:   Fri Nov 9 02:48:09 2012 +0000

    Refactor scheduling weights.
    
    This makes scheduling weights more plugin friendly and creates shared
    code that can be used by the host scheduler as well as the future cells
    scheduler.  Weighing classes can now be specified much like you can
    specify scheduling host filters.
    
    The new weights code reverses the old behavior where lower weights win.
    Higher weights are now the winners.
    
    The least_cost module and configs have been deprecated, but are still
    supported for backwards compatibility.  The code has moved to
    nova.scheduler.weights.least_cost and been modified to work with the new
    loadable-class code.  If any of the least_cost related config options are
    specified, this least_cost weigher will be used.
    
    For those not overriding the default least_cost config values, the new
    RamWeigher class will be used.  The default behavior of the RamWeigher
    class is the same default behavior as the old least_cost module.
    
    The new weights code introduces a new config option
    'scheduler_weight_classes' which is used to specify which weigher classes
    to use.  The default is 'all classes', but modified if least_cost
    deprecated config options are used, as mentioned above.
    
    The RamWeigher class introduces a new config option
    'ram_weight_multiplier'.  The default of 1.0 causes weights equal to the
    free memory in MB to be returned, thus hosts with more free memory are
    preferred (causes equal spreading).  Changing this value to a negative
    number such as -1.0 will cause reverse behavior (fill first).
    
    DocImpact
    
    Change-Id: I1e5e5039c299db02f7287f2d33299ebf0b9732ce