Message-ID: <1369835025.5109.21.camel@edumazet-glaptop>
Subject: RE: [PATCH v6 net-next 1/5] net: add napi_id and hash
From: Eric Dumazet <eric.dumazet@gmail.com>
To: David Laight <David.Laight@ACULAB.COM>
Cc: Eliezer Tamir <eliezer.tamir@linux.intel.com>,
        David Miller <davem@davemloft.net>, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, Jesse Brandeburg <jesse.brandeburg@intel.com>,
        Don Skidmore <donald.c.skidmore@intel.com>,
        e1000-devel@lists.sourceforge.net,
        Willem de Bruijn <willemb@google.com>,
        Andi Kleen <andi@firstfloor.org>, HPA <hpa@zytor.com>,
        Eilon Greenstien <eilong@broadcom.com>,
        Or Gerlitz <or.gerlitz@gmail.com>, Alex Rosenbaum <alexr@mellanox.com>,
        Eliezer Tamir <eliezer@tamir.org.il>
Date: Wed, 29 May 2013 06:43:45 -0700
In-Reply-To: <AE90C24D6B3A694183C094C60CF0A2F6026B7256@saturn3.aculab.com>
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	 <1369832201.5109.8.camel@edumazet-glaptop>
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On Wed, 2013-05-29 at 14:09 +0100, David Laight wrote:
> > > Adds a napi_id and a hashing mechanism to lookup a napi by id.
> 
> Is this one of the places where the 'id' can be selected
> so that the 'hash' lookup never collides?

Very few devices will ever call napi_hash_add()

[ Real NIC RX queues, not virtual devices ]

We use a hash table with 256 slots, the chance of collision is about 0%

Lets not over engineer the thing before its even used.


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