From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [net-next PATCH V2 3/9] net: frag, move LRU list maintenance
 outside of rwlock
Date: Thu, 29 Nov 2012 12:48:39 -0500 (EST)
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From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 29 Nov 2012 09:43:24 -0800

> Use a schem with a hash table of 256 (or 1024) slots.
> 
> Each slot/bucket has : 
>   - Its own spinlock.
>   - List of items
>   - A limit of 5 (or so) elems in the list.
> 
> No more LRU, no more rehash (thanks to jhash and the random seed at boot
> or first frag created), no more reader-writer lock.
> 
> Use a percpu_counter to implement ipfrag_low_thresh/ipfrag_high_thresh

If we limit the chain sizes to 5 elements, there is no need for
any thresholds at all.