From: Mihai Maruseac <mihai.maruseac@gmail.com>
To: Stephen Hemminger <shemminger@vyatta.com>
Cc: davem@davemloft.net, eric.dumazet@gmail.com,
kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org,
kaber@trash.net, netdev@vger.kernel.org,
Mihai Maruseac <mmaruseac@ixiacom.com>,
Daniel Baluta <dbaluta@ixiacom.com>
Subject: Re: [PATCH] ipv6/addrconf: speedup /proc/net/if_inet6 filling
Date: Thu, 5 Jan 2012 16:07:33 +0200 [thread overview]
Message-ID: <CAOMsUM+wJm0YiTZpAVh+4GYJdDKFmSCqZek_ykaYuvHYXx5MFw@mail.gmail.com> (raw)
In-Reply-To: <CAOMsUMKp_7w2+0bBTFbQk3HKpobJQd8b2vi6_zTTzGjtZ_+OMA@mail.gmail.com>
On Wed, Jan 4, 2012 at 7:03 PM, Mihai Maruseac <mihai.maruseac@gmail.com> wrote:
> On Wed, Jan 4, 2012 at 6:22 PM, Stephen Hemminger <shemminger@vyatta.com> wrote:
>> On Wed, 4 Jan 2012 11:31:35 +0200
>> Mihai Maruseac <mihai.maruseac@gmail.com> wrote:
>>
>>> This ensures a linear behaviour when filling /proc/net/if_inet6 thus making
>>> ifconfig run really fast on IPv6 only addresses. In fact, with this patch and
>>> the IPv4 one sent a while ago, ifconfig will run in linear time regardless of
>>> address type.
>>>
>>> IPv4 related patch: f04565ddf52e401880f8ba51de0dff8ba51c99fd
>>> dev: use name hash for dev_seq_ops
>>> ...
>>>
>>> Some statistics (running ifconfig > /dev/null on a different setup):
>>>
>>> iface count / IPv6 no-patch time / IPv6 patched time / IPv4 time
>>> ----------------------------------------------------------------
>>> 6250 | 0.23 s | 0.13 s | 0.11 s
>>> 12500 | 0.62 s | 0.28 s | 0.22 s
>>> 25000 | 2.91 s | 0.57 s | 0.46 s
>>> 50000 | 11.37 s | 1.21 s | 0.94 s
>>> 128000 | 86.78 s | 3.05 s | 2.54 s
>>>
>>> Signed-off-by: Mihai Maruseac <mmaruseac@ixiacom.com>
>>> Cc: Daniel Baluta <dbaluta@ixiacom.com>
>>> ---
>>> net/ipv6/addrconf.c | 43 ++++++++++++++++++++++++++++---------------
>>> 1 files changed, 28 insertions(+), 15 deletions(-)
>>>
>>
>>
>> What about netlink? Also ifconfig is really considered deprecated,
>> especially for ipv6 usage.
>
> Yes, ifconfig is deprecated but the /proc/net/if_inet6 file can be
> used in a lot of bash scripts and this was what we wanted to optimize.
>
> We tried to look at the netlink sockets used in iproute2 but there
> seems to be no way to improve the performance there. We used 3 pair of
> eyes for this before giving up.
>
> I'll come back with statistics from ip a s in at most 24 hours, I
> cannot test right now.
Here are the statistics comparing ip a s with ifconfig, as promised:
* for IPv6:
iface count / ifconfig / ip a s
----------------------------------------------
6250 | 0.13 s | 1.23 s
12500 | 0.28 s | 5.03 s
25000 | 0.57 s | 20.17 s
50000 | 1.21 s | 87.25 s
128000 | 3.05 s | 968.12 s
* for IPv4:
iface count / ifconfig / ip a s
----------------------------------------------
6250 | 0.11 s | 0.61 s
12500 | 0.22 s | 2.49 s
25000 | 0.46 s | 10.12 s
50000 | 0.94 s | 40.36 s
128000 | 2.54 s | 293.14 s
It seems that an optimisation for the ip case is required. We have a
quadratic behaviour here too.
Thanks,
Mihai
next prev parent reply other threads:[~2012-01-05 14:07 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-04 9:31 [PATCH] ipv6/addrconf: speedup /proc/net/if_inet6 filling Mihai Maruseac
2012-01-04 16:22 ` Stephen Hemminger
2012-01-04 17:03 ` Mihai Maruseac
2012-01-05 14:07 ` Mihai Maruseac [this message]
2012-01-04 21:01 ` David Miller
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