From: Eric Dumazet <eric.dumazet@gmail.com>
To: Stephen Hemminger <shemminger@vyatta.com>
Cc: netdev@vger.kernel.org
Subject: Re: neighbour table RCU
Date: Tue, 01 Sep 2009 08:50:17 +0200 [thread overview]
Message-ID: <4A9CC429.5020803@gmail.com> (raw)
In-Reply-To: <20090831150453.3437a65c@nehalam>
Stephen Hemminger a écrit :
> Looking at the neighbour table, it should be possible to get
> rid of the two reader/writer locks. The hash table lock is pretty
> amenable to RCU, but the dynamic resizing makes it non-trivial.
> Thinking of using a combination of RCU and sequence counts so that the
> reader would just rescan if resize was in progress.
I am not sure neigh_tbl_lock rwlock should be changed, I did not
see any contention on it.
>
> The reader/writer lock on the neighbour entry is more of a problem.
> Probably would be simpler/faster to change it into a spinlock and
> be done with it.
>
> The reader/writer lock is also used for the proxy list hash table,
> but that can just be a simple spinlock.
>
This is probably is the only thing we want to do at this moment,
halving atomic ops on neigh_resolve_output()
But why neigh_resolve_output() was called so much in the bench
is the question...
next prev parent reply other threads:[~2009-09-01 6:50 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-31 22:04 neighbour table RCU Stephen Hemminger
2009-09-01 6:50 ` Eric Dumazet [this message]
2009-09-01 15:55 ` Octavian Purdila
2009-09-01 16:14 ` Eric Dumazet
2009-09-01 16:56 ` Octavian Purdila
2009-09-01 16:23 ` Stephen Hemminger
2009-09-01 15:59 ` Stephen Hemminger
2009-09-01 16:13 ` Eric Dumazet
2009-09-01 21:24 ` Stephen Hemminger
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