[ovs-dev] [PATCH 1/2] ovs-vswitchd: Correct the documentation on the limits for bridges and ports.

[Gurucharan Shetty]

On Thu, Jul 11, 2013 at 10:34 AM, Gurucharan Shetty <shettyg at nicira.com>wrote:

> On Thu, Jul 11, 2013 at 10:22 AM, Ben Pfaff <blp at nicira.com> wrote:
>
>> On Thu, Jul 11, 2013 at 09:37:45AM -0700, Gurucharan Shetty wrote:
>> > Signed-off-by: Gurucharan Shetty <gshetty at nicira.com>
>>
>> I'm not sure it's worth mentioning the 65,280 port limit, because it's
>> about the same as the maximum number of file descriptors.
>>
>> At first thought, these limits seemed Linux specific, but I think that
>> FreeBSD also needs a file descriptor per port (for a pcap handle), so
>> maybe it's not worth saying that it is Linux specific.  The final note
>> about performance beyond 1,024 ports is definitely specific to the
>> Linux kernel datapath though.
>>
> Okay. How about the following wording?
>
> ovs-vswitchd started through ovs-ctl provides a limit of 5000 file
> descriptors.  Creation of a single bridge consumes 3 file descriptors and
> adding a port consumes 1 file descriptor.  The limits on the number of
> bridges and ports is decided by the availability of file descriptors.  (For
> Linux kernel datapath, performance will degrade beyond 1,024 ports per
> bridge due to fixed hash table sizing.)
>
Or probably make the entire thing Linux specific.
ovs-vswitchd started through ovs-ctl provides a limit of 5000 file
descriptors. The limits on the number of bridges and ports is decided by
the availability of file descriptors. On Linux, creation of a single bridge
consumes 3 file descriptors and adding a port consumes 1 file descriptor.
Performance will degrade beyond 1,024 ports per bridge due to fixed hash
table sizing. Other platforms may have different limitations.


>
>
>>
>> Thanks,
>>
>> Ben.
>>
>
>
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