[ovs-dev] [PATCH v5 4/6] classifier: Retire partitions.

Jarno Rajahalme jrajahalme at nicira.com
Wed Aug 26 23:05:59 UTC 2015


> On Aug 26, 2015, at 2:40 PM, Ben Pfaff <blp at nicira.com> wrote:
> 
> On Fri, Aug 21, 2015 at 03:25:21PM -0700, Jarno Rajahalme wrote:
>> Classifier partitions allowed skipping subtables when if was known
>> from the flow's metadata field that the subtable cannot possibly
>> match.  This functionality was later implemented in a more general
>> fashion by staged lookup, where the first stage also covers the
>> metadata field, among the rest of the non-packet fields in the struct
>> flow.  While in theory skipping a subtable on the basis of the
>> metadata field alone could produce more effective wildcards, on the
>> basis of our testsuite coverage it does not seem to be the case, as
>> removing the partitioning feature did not result in any test failures.
>> 
>> Removing the partitioning feature makes classifier lookups roughly 20%
>> faster when a wildcard mask is not needed, and roughly 10% faster when
>> a wildcard mask is needed, as tested with the test-classifier
>> benchmark with one lookup thread.
>> 
>> Found by profiling with 'perf'.
>> 
>> Signed-off-by: Jarno Rajahalme <jrajahalme at nicira.com>
> 
> Acked-by: Ben Pfaff <blp at nicira.com <mailto:blp at nicira.com>>

Pushed to master,

  Jarno




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