Subject: Re: Extensible hashing and RCU

From: Andi Kleen <[email-masked]>
Date: 19 Feb 2007 23:10:09 +0100

Evgeniy Polyakov <[email-masked]> writes:
> 
> My experiment shows almost 400 nsecs without _any_ locks - they are
> removed completely - it is pure hash selection/list traverse time.

Are you sure you're not measuring TLB misses too? In user space
you likely use 4K pages. The kernel would use 2MB pages.
I would suggest putting the tables into hugetlbfs allocated memory
in your test program.

-Andei