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From: David Miller <davem@davemloft.net>
To: dada1@cosmosbay.com
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH] NET : UDP can use sk_hash to speedup lookups
Date: Fri, 09 Feb 2007 15:45:11 -0800 (PST)	[thread overview]
Message-ID: <20070209.154511.92582666.davem@davemloft.net> (raw)
In-Reply-To: <200702091844.16803.dada1@cosmosbay.com>

From: Eric Dumazet <dada1@cosmosbay.com>
Date: Fri, 9 Feb 2007 18:44:16 +0100

> In a prior patch, I introduced a sk_hash field (__sk_common.skc_hash)  to let 
> tcp lookups use one cache line per unmatched entry instead of two.
> 
> We can also use sk_hash to speedup UDP part as well. We store in sk_hash the 
> hnum value, and use sk->sk_hash (same cache line than 'next' pointer), 
> instead of inet->num (different cache line)
> 
> Note : We still have a false sharing problem for SMP machines, because 
> sock_hold(sock) dirties the cache line containing the 'next' pointer. Not 
> counting the udp_hash_lock rwlock. (did someone mentioned RCU ? :) )
> 
> Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>

Applied, thanks Eric.

      reply	other threads:[~2007-02-09 23:45 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-12-19  8:56 [PATCH] irlan: handle out of memory errors Akinobu Mita
2006-12-19 22:47 ` Samuel Ortiz
2007-02-07  8:12   ` David Miller
2007-02-07 10:59     ` [PATCH] NET : change layout of ehash table Eric Dumazet
2007-02-08 22:56       ` David Miller
2007-02-09  9:18         ` Andi Kleen
2007-02-09  8:40           ` David Miller
2007-02-09  8:57             ` Andi Kleen
2007-02-09  9:06             ` Eric Dumazet
2007-02-09  9:15               ` David Miller
2007-02-09  9:36                 ` Eric Dumazet
2007-02-09  9:43                   ` David Miller
2007-02-09 10:10                     ` Andi Kleen
2007-02-09 17:44                     ` [PATCH] NET : UDP can use sk_hash to speedup lookups Eric Dumazet
2007-02-09 23:45                       ` David Miller [this message]

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