Memcached implementation inquiry

[Lexington Luthor]

marc at corky.net wrote:
> Hi,
> 
> mysql's scaling problem, especially on Linux, was recently found to be a 
> sub-optimal implementation of malloc when it comes to threads.
> 
> If you preload google's malloc lib for mysqld you'll see a huge 
> difference past ~1000 TPS allowing it to scale almost linearly as well.
> 
> Search for 'mysqld google malloc'
> 

At what kind of (OLTP) load does mysql begin to be hampered by lock 
contention? Can you link to any thorough tests done to find this out? 
Every test that I can find using google seems to be done by mysql 
themselves or storage engine vendors, which are no doubt biased.

Redards,
LL