From: "Octavian Purdila" <opurdila@ixiacom.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>,
"David Miller" <davem@davemloft.net>
Cc: <hans.schillstrom@ericsson.com>, <daniel.lezcano@free.fr>,
<netdev@vger.kernel.org>
Subject: Re: BUG ? ipip unregister_netdevice_many()
Date: Thu, 14 Oct 2010 22:21:02 +0300 [thread overview]
Message-ID: <1287084062.1601.36.camel@Nokia-N900-42-11> (raw)
> > How can it make a real difference even in this case? We'll obliterate
> > all the entries, and then on subsequent passes we'll find nothing
> > matching that namespace any more.
> >
> > Show me performance tests that show it makes any difference, please.
>
> Octavian did you happen to measure the performance difference when you
> added batching of routing table flushes?
>
Unfortunatelly I dont't have the numbers anymore, but I remember it was noticeable when using a large number of interfaces (10K) - if I remember correctly around 1 second out of 10 for the whole unregister process.
BTW, another bottleneck for mass unregister while interfaces are up is dev_deactivate / dev_close. I experimented with "batchifying" it and for 32K interfaces the time went down from 5mins to 30s.
The patch I have is not pretty, it basically creates another 2 functions for each of dev_close and dev_deactivate for pre and post synchronise_rcu barrier.
next reply other threads:[~2010-10-14 19:20 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-14 19:21 Octavian Purdila [this message]
-- strict thread matches above, loose matches on Subject: below --
2010-10-07 8:48 BUG ? ipip unregister_netdevice_many() Hans Schillstrom
2010-10-08 11:19 ` Daniel Lezcano
2010-10-08 11:53 ` Hans Schillstrom
2010-10-08 12:28 ` Hans Schillstrom
2010-10-08 15:53 ` Daniel Lezcano
2010-10-08 16:17 ` Daniel Lezcano
2010-10-08 16:58 ` Eric W. Biederman
2010-10-08 17:29 ` Daniel Lezcano
2010-10-08 17:47 ` Daniel Lezcano
2010-10-08 16:45 ` Eric W. Biederman
2010-10-08 17:20 ` David Miller
2010-10-08 17:32 ` Eric W. Biederman
2010-10-12 20:05 ` David Miller
2010-10-13 11:19 ` Jarek Poplawski
2010-10-13 21:58 ` David Miller
2010-10-14 6:41 ` Hans Schillstrom
2010-10-13 22:16 ` Daniel Lezcano
2010-10-13 23:23 ` David Miller
2010-10-14 3:57 ` Eric Dumazet
2010-10-14 23:28 ` Paul E. McKenney
2010-10-14 4:40 ` Eric W. Biederman
2010-10-14 4:50 ` David Miller
2010-10-14 5:20 ` Eric W. Biederman
2010-10-14 15:09 ` David Miller
2010-10-14 18:35 ` Eric W. Biederman
2010-10-08 16:51 ` Eric W. Biederman
2010-10-08 16:06 ` Eric W. Biederman
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