From: Eric Dumazet <eric.dumazet@gmail.com>
To: Stephen Hemminger <shemminger@vyatta.com>
Cc: David Miller <davem@davemloft.net>,
kaber@trash.net, netdev@vger.kernel.org,
remi.denis-courmont@nokia.com
Subject: Re: [PATCH net-next-2.6] net: add rcu protection to netdev->ifalias
Date: Wed, 18 May 2011 00:39:16 +0200 [thread overview]
Message-ID: <1305671956.6741.25.camel@edumazet-laptop> (raw)
In-Reply-To: <20110517152503.2f7244f3@nehalam>
Le mardi 17 mai 2011 à 15:25 -0700, Stephen Hemminger a écrit :
> I am beginning to think the idea of optimizing case of "ip link show"
> running in background with adding/removing network devices is silly.
> And switching to RCU leads to all sorts of corner cases where only
> partial data will be read. Is it really worth it?
>
Just try "modprobe dummy numdummies=1000", and watch load average
raising, because so many processes want to hold RTNL, and the
rtnl_trylock() crazy thing make them spin (restart syscall, and find
RTNL locked again... wooo...)
Some workloads hit RTNL quite hard, and monitoring tools were sometime
frozen for unexpected long times. (before the patch, when we used to
hold RTNL in dump())
I dont know, if it happens to be too hard, we'll just stick again rtnl
for "ip link show" ;)
next prev parent reply other threads:[~2011-05-17 22:39 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-28 8:56 [PATCH net-next-2.6] net: dont hold rtnl mutex during netlink dump callbacks Eric Dumazet
2011-04-28 15:40 ` Stephen Hemminger
2011-04-28 15:43 ` Stephen Hemminger
2011-04-28 15:53 ` Eric Dumazet
2011-05-02 22:27 ` David Miller
2011-05-17 22:18 ` [PATCH net-next-2.6] net: add rcu protection to netdev->ifalias Eric Dumazet
2011-05-17 22:25 ` Stephen Hemminger
2011-05-17 22:39 ` Eric Dumazet [this message]
2011-05-18 4:35 ` Eric Dumazet
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