Re: [RFC] NUMA futex hashing

[Nick Piggin]

Eric Dumazet wrote:

> We certainly can. But if you insist of using mmap sem at all, then we have a 
> problem.
>
> rbtree would not reduce cacheline bouncing, so :
>
> We could use a hashtable (allocated on demand) of size N, N depending on 
> NR_CPUS for example. each chain protected by a private spinlock. If N is well 
> chosen, we might reduce lock cacheline bouncing. (different threads fighting 
> on different private futexes would have a good chance to get different 
> cachelines in this hashtable)

See other mail. We already have a hash table ;)

--
SUSE Labs, Novell Inc.
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