From: Corey Minyard <minyard@acm.org>
To: David Miller <davem@davemloft.net>
Cc: dada1@cosmosbay.com, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org, shemminger@vyatta.com,
paulmck@linux.vnet.ibm.com
Subject: Re: [PATCH 3/3] Convert the UDP hash lock to RCU
Date: Mon, 06 Oct 2008 18:08:09 -0500 [thread overview]
Message-ID: <48EA9A59.1090306@acm.org> (raw)
In-Reply-To: <20081006.144002.56418911.davem@davemloft.net>
David Miller wrote:
> From: Eric Dumazet <dada1@cosmosbay.com>
> Date: Mon, 06 Oct 2008 23:22:31 +0200
>
>
>> Me wondering what impact this synchronize_rcu() can have on mono-threaded
>> VOIP applications using lot of UDP sockets. What is the maximum delay of
>> this function ?
>>
>
> The cost is enormous, we really can't use it here.
>
> I have a patch that did top-level socket destruction using RCU,
> and that didn't use synchronize_rcu(), and that killed connection
> rates by up to %20.
>
> I can only imagine what the cost would be if I had to add such a call
> in there.
>
> Really, I can't consider these changes seriously, as-is.
>
>
Would using SLAB_DESTROY_BY_RCU be ok, or would that be too expensive?
-corey
next prev parent reply other threads:[~2008-10-06 23:08 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-06 18:50 Corey Minyard
2008-10-06 21:22 ` Eric Dumazet
2008-10-06 21:40 ` David Miller
2008-10-06 23:08 ` Corey Minyard [this message]
2008-10-07 8:37 ` Evgeniy Polyakov
2008-10-07 14:16 ` Christoph Lameter
2008-10-07 14:29 ` Evgeniy Polyakov
2008-10-07 14:38 ` Christoph Lameter
2008-10-07 14:33 ` Paul E. McKenney
2008-10-07 14:45 ` Christoph Lameter
2008-10-07 15:07 ` Eric Dumazet
2008-10-07 15:07 ` Paul E. McKenney
2008-10-07 5:24 ` Eric Dumazet
2008-10-07 8:54 ` Benny Amorsen
2008-10-07 12:59 ` Eric Dumazet
2008-10-07 14:07 ` Stephen Hemminger
2008-10-07 20:55 ` David Miller
2008-10-07 21:20 ` Stephen Hemminger
2008-10-08 13:55 ` Eric Dumazet
2008-10-08 18:45 ` David Miller
2008-10-07 16:43 ` Corey Minyard
2008-10-07 18:26 ` David Miller
2008-10-08 8:35 ` Eric Dumazet
2008-10-08 16:38 ` David Miller
2008-10-07 8:31 ` Peter Zijlstra
2008-10-07 14:36 ` Paul E. McKenney
2008-10-07 18:29 ` David Miller
2008-10-06 22:07 ` Corey Minyard
2008-10-07 8:17 ` Peter Zijlstra
2008-10-07 9:24 ` Eric Dumazet
2008-10-07 14:15 ` Christoph Lameter
2008-10-07 14:38 ` Paul E. McKenney
2008-10-07 14:50 ` Eric Dumazet
2008-10-07 15:05 ` Paul E. McKenney
2008-10-07 15:09 ` Peter Zijlstra
2008-10-07 15:23 ` Christoph Lameter
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