From: Steffen Klassert <steffen.klassert@secunet.com>
To: David Miller <davem@davemloft.net>
Cc: timo.teras@iki.fi, netdev@vger.kernel.org
Subject: Re: [PATCH 0/4] Fix routing metrics
Date: Thu, 9 Feb 2012 13:44:11 +0100 [thread overview]
Message-ID: <20120209124411.GJ23142@secunet.com> (raw)
In-Reply-To: <20120208.151837.75403230557283008.davem@davemloft.net>
On Wed, Feb 08, 2012 at 03:18:37PM -0500, David Miller wrote:
> From: Steffen Klassert <steffen.klassert@secunet.com>
> Date: Wed, 8 Feb 2012 08:30:37 +0100
>
> > On Mon, Feb 06, 2012 at 03:29:16PM -0500, David Miller wrote:
> >>
> >> Thinking about this, it seems overkill to check this on every metric
> >> access.
> >>
> >> You have an opportunity to validate metrics when the peer is bound to
> >> the route.
> >>
> >> This is because any change to the FIB metrics, is in turn a change
> >> to the FIB, which therefore invalidates the entire routing cache.
> >>
> >> So you can be sure that a new route cache entry will be created, and
> >> at that creation time you can ensure that we'll respect the updated
> >> FIB metrics if encessary.
> >
> > Not sure if I get you right here, but that's what this patchset
> > does. It invalidates the metrics on the peer by incrementing
> > peer_genid in rt_cache_invalidate() which is invoked on every FIB
> > change. Then, on slowpath route lookup it checks in rt_init_metrics()
> > whether the peer_genid changed. If it changed, it exchanges the
> > invalidated merics with new ones and copies the informations from
> > the FIB into it.
>
> If the routing cache is invalided, you'll "see" this updated inetpeer
> because every single routing cache entry will get rebuilt.
Hm, I still don't get your point. Could you specify this please?
When a route cache entry is created and the peer_genid does not match
the genid on the inetpeer, fresh inetpeer metrics are allocated and
then published. After that, the new metrics are in proper state and
ready to use.
next prev parent reply other threads:[~2012-02-09 12:44 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-02 10:11 [PATCH 0/4] Fix routing metrics Steffen Klassert
2012-02-02 10:12 ` [PATCH 1/4] inetpeer: Allocate the peer metrics dynamically Steffen Klassert
2012-02-02 10:12 ` [PATCH 2/4] net: Unlink the inetpeer metrics from dst_entry Steffen Klassert
2012-02-02 10:13 ` [PATCH 3/4] inetpeer: protect the inetpeerpeer metrics with rcu Steffen Klassert
2012-02-02 10:14 ` [PATCH 4/4] route: Invalidate the peer metrics along with the routing cache Steffen Klassert
2012-02-06 20:29 ` [PATCH 0/4] Fix routing metrics David Miller
2012-02-08 7:30 ` Steffen Klassert
2012-02-08 20:18 ` David Miller
2012-02-09 12:44 ` Steffen Klassert [this message]
2012-02-09 18:40 ` David Miller
2012-02-10 6:50 ` Steffen Klassert
2012-02-10 7:38 ` David Miller
2012-02-10 7:51 ` Steffen Klassert
2012-02-10 8:12 ` David Miller
2012-02-10 8:44 ` Steffen Klassert
2012-02-10 18:25 ` David Miller
2012-02-21 6:19 ` Steffen Klassert
2012-02-21 6:36 ` David Miller
2012-02-21 8:18 ` Steffen Klassert
2012-02-21 19:24 ` David Miller
2012-02-24 9:08 ` Steffen Klassert
2012-02-24 9:13 ` David Miller
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