From: Eric Dumazet <eric.dumazet@gmail.com>
To: paulmck@linux.vnet.ibm.com
Cc: Octavian Purdila <opurdila@ixiacom.com>,
Benjamin LaHaise <bcrl@lhnet.ca>,
netdev@vger.kernel.org, Cosmin Ratiu <cratiu@ixiacom.com>
Subject: Re: [PATCH] net: allow netdev_wait_allrefs() to run faster
Date: Sat, 24 Oct 2009 16:24:27 +0200 [thread overview]
Message-ID: <4AE30E1B.5080008@gmail.com> (raw)
In-Reply-To: <20091024135214.GB6638@linux.vnet.ibm.com>
Paul E. McKenney a écrit :
> On Sat, Oct 24, 2009 at 10:49:55AM +0200, Eric Dumazet wrote:
>>
>> On my dev machine, a synchronize_rcu() lasts between 2 an 12 ms
>
> That sounds like the right range, depending on what else is happening
> on the machine at the time.
>
> The synchronize_rcu_expedited() primitive would run in the 10s-100s
> of microseconds. It involves a pair of wakeups and a pair of context
> switches on each CPU.
>
Hmm... I'll make some experiments Monday and post results, but it seems very
promising.
Do you think the "on_each_cpu(flush_backlog, dev, 1);"
we perform right before calling netdev_wait_allrefs() could be changed
somehow to speedup rcu callbacks ? Maybe we ould avoid sending IPI twice to
cpus ?
Thanks
next prev parent reply other threads:[~2009-10-24 14:24 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-17 22:18 [PATCH/RFC] make unregister_netdev() delete more than 4 interfaces per second Benjamin LaHaise
2009-10-18 4:26 ` Eric Dumazet
2009-10-18 16:13 ` Benjamin LaHaise
2009-10-18 17:51 ` Eric Dumazet
2009-10-18 18:21 ` Benjamin LaHaise
2009-10-18 19:36 ` Eric Dumazet
2009-10-21 12:39 ` Octavian Purdila
2009-10-21 15:40 ` [PATCH] net: allow netdev_wait_allrefs() to run faster Eric Dumazet
2009-10-21 16:09 ` Eric Dumazet
2009-10-21 16:51 ` Benjamin LaHaise
2009-10-21 19:54 ` Eric Dumazet
2009-10-29 23:07 ` Eric W. Biederman
2009-10-29 23:38 ` Benjamin LaHaise
2009-10-30 1:45 ` Eric W. Biederman
2009-10-30 14:35 ` Benjamin LaHaise
2009-10-30 14:43 ` Eric Dumazet
2009-10-30 23:25 ` Eric W. Biederman
2009-10-30 23:53 ` Benjamin LaHaise
2009-10-31 0:37 ` Eric W. Biederman
2010-08-09 17:23 ` Ben Greear
2010-08-09 17:34 ` Benjamin LaHaise
2010-08-09 17:44 ` Ben Greear
2010-08-09 17:48 ` Benjamin LaHaise
2010-08-09 18:03 ` Ben Greear
2010-08-09 19:59 ` Eric W. Biederman
2010-08-09 21:03 ` Benjamin LaHaise
2010-08-09 21:17 ` Eric W. Biederman
2009-10-21 16:55 ` Octavian Purdila
2009-10-23 21:13 ` Paul E. McKenney
2009-10-24 4:35 ` Eric Dumazet
2009-10-24 5:49 ` Paul E. McKenney
2009-10-24 8:49 ` Eric Dumazet
2009-10-24 13:52 ` Paul E. McKenney
2009-10-24 14:24 ` Eric Dumazet [this message]
2009-10-24 14:46 ` Paul E. McKenney
2009-10-24 23:49 ` Octavian Purdila
2009-10-25 4:47 ` Paul E. McKenney
2009-10-25 8:35 ` Eric Dumazet
2009-10-25 15:19 ` Octavian Purdila
2009-10-25 19:28 ` Eric Dumazet
2009-10-24 20:22 ` Stephen Hemminger
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