[ovs-dev] [PATCHv3] datapath: Cache netlink flow key, mask on flow_put.

Joe Stringer joestringer at nicira.com
Mon Jul 21 02:34:32 UTC 2014


On 21 July 2014 10:28, Joe Stringer <joestringer at nicira.com> wrote:

> On 19 July 2014 06:13, Jesse Gross <jesse at nicira.com> wrote:
>
>> It's true, the field ordering is not significant if you understand all
>> of the fields. The concern is that userspace may want to keep track of
>> flows even if it doesn't understand all of the fields (for example, it
>> can determine that the kernel provides information about some
>> additional fields that userspace doesn't care about and just mask
>> those out). In this case, to keep track of what is in the kernel,
>> userspace would likely do a hash and comparison over the byte stream
>> of the key. In that situation, even if reordering wouldn't cause the
>> meaning to change, it would cause the comparison to fail.
>>
>
> I see, thanks for explaining. In that case, I'll look at preparing a patch
> that does the caching upon the first flow dump.
>

The new version has a slightly different subject line:
http://openvswitch.org/pipermail/dev/2014-July/042913.html



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