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From: Eric Dumazet <eric.dumazet@gmail.com>
To: David Laight <David.Laight@ACULAB.COM>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>,
	"David S. Miller" <davem@davemloft.net>,
	Hannes Frederic Sowa <hannes@stressinduktion.org>,
	netdev@vger.kernel.org
Subject: RE: [net-next PATCH 2/3] net: fix enforcing of fragment queue hash list depth
Date: Fri, 19 Apr 2013 04:14:50 -0700	[thread overview]
Message-ID: <1366370090.3205.109.camel@edumazet-glaptop> (raw)
In-Reply-To: <AE90C24D6B3A694183C094C60CF0A2F6026B71EB@saturn3.aculab.com>

On Fri, 2013-04-19 at 11:41 +0100, David Laight wrote:
> > The 64 slots hash table was chosen years ago, when machines had 3 order
> > of magnitude less ram than today.
> > 
> > Before hash resizing, I would just bump hash size to something more
> > reasonable like 1024.
> 
> While that is true of many systems, there are embedded systems
> with much less ram than the typical x86 desktop or server.
> 
> There seem to be quite a lot of large hash tables appearing
> that on many small systems will never contain a significant
> number of entries and just waste precious memory.

Embedded systems run linux since ages, and their memory also increased
by 2 order of magnitude since 1995.

If they run linux-3.10, using 4096 bytes of 8192 bytes for the hash
table is fine.

We are not going to add yet another ifdef, for such a small amount of
ram.

The code that we will add to do the resize will be larger than this.

  reply	other threads:[~2013-04-19 11:14 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-18 21:37 [net-next PATCH 0/3] net: frag code fixes and RFC for LRU removal Jesper Dangaard Brouer
2013-04-18 21:37 ` [net-next PATCH 1/3] net: fix race bug in fragmentation create code Jesper Dangaard Brouer
2013-04-19  1:00   ` Hannes Frederic Sowa
2013-04-19  8:09     ` Jesper Dangaard Brouer
2013-04-18 21:38 ` [net-next PATCH 2/3] net: fix enforcing of fragment queue hash list depth Jesper Dangaard Brouer
2013-04-19  0:52   ` Hannes Frederic Sowa
2013-04-19 10:11   ` Eric Dumazet
2013-04-19 10:41     ` David Laight
2013-04-19 11:14       ` Eric Dumazet [this message]
2013-04-19 12:19     ` Jesper Dangaard Brouer
2013-04-19 12:45       ` Hannes Frederic Sowa
2013-04-19 14:29         ` Jesper Dangaard Brouer
2013-04-19 15:06           ` Hannes Frederic Sowa
2013-04-19 19:44           ` Hannes Frederic Sowa
2013-04-22  9:10             ` Jesper Dangaard Brouer
2013-04-22 14:54               ` Hannes Frederic Sowa
2013-04-22 16:30                 ` Jesper Dangaard Brouer
2013-04-22 17:49                 ` Jesper Dangaard Brouer
2013-04-23  0:20                   ` Hannes Frederic Sowa
2013-04-23 14:19                     ` Jesper Dangaard Brouer
2013-04-23 20:54                       ` Hannes Frederic Sowa
2013-04-19 14:42       ` Eric Dumazet
2013-04-19 14:45       ` Eric Dumazet
2013-04-19 14:45       ` Eric Dumazet
2013-04-19 14:49       ` Eric Dumazet
2013-04-24 13:35         ` Jesper Dangaard Brouer
2013-04-24 15:05           ` Eric Dumazet
2013-04-18 21:39 ` [RFC net-next PATCH 3/3] net: remove fragmentation LRU list system Jesper Dangaard Brouer

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