From: David Miller <davem@davemloft.net>
To: steffen.klassert@secunet.com
Cc: timo.teras@iki.fi, netdev@vger.kernel.org
Subject: Re: [PATCH 0/4] Fix routing metrics
Date: Fri, 10 Feb 2012 02:38:15 -0500 (EST) [thread overview]
Message-ID: <20120210.023815.192069104397847238.davem@davemloft.net> (raw)
In-Reply-To: <20120210065031.GK23142@secunet.com>
From: Steffen Klassert <steffen.klassert@secunet.com>
Date: Fri, 10 Feb 2012 07:50:31 +0100
> On Thu, Feb 09, 2012 at 01:40:10PM -0500, David Miller wrote:
>> From: Steffen Klassert <steffen.klassert@secunet.com>
>> >
>> > 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.
>>
>> Right, which is exactly what you want to happen.
>>
>> Checking on every metric access is therefore pointless and needless.
>>
>> The peer_genid only increments when the routing cache is flushed,
>> therefore every subsequent access to the metrics will go through the
>> route cache entry creation path first, and therefore that will make
>> sure fresh inetpeer metrics will be allocated since the peer_genid
>> does not match.
>
> I fully agree with you here. But we check for the genid just in
> rt_init_metrics() which is invoked only on route cache entry
> creation. There is no check when the metrics are accessed,
> because the metrics on the inetpeer are valid on every access.
Every routing cache entry we will use after the flush will be
a newly created one! All the old ones will be stop being used.
next prev parent reply other threads:[~2012-02-10 7:38 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
2012-02-09 18:40 ` David Miller
2012-02-10 6:50 ` Steffen Klassert
2012-02-10 7:38 ` David Miller [this message]
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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