Re: mutex contention for the query cache

[Sergei Golubchik]

Hi!

> >> Query cache as it's done now is dirt cheap (concurrency can be
> >> fixed).
> > 
> > I have some big doubts that this is the case. I think you will find
> > that the lock methods being deployed right now around RW are not
> > going to scale on any of the hardware we are seeing deployed. As is
> > you will find that the general rule of thumb today is to just get
> > rid of it. For anyone wanting to make use of the hardware that they
> > are deploying the only solution is to junk it.

Junk because of the problems of the current implementation, not because
the idea is wrong.
 
> /me tries to promote RCU as silver bullet
> if mysqld can define a well-defined grace period, then /me thinks this
> can be used in several places

I dno't know, how do you do RCU in the userspace ?
 
Regards / Mit vielen Grüssen,
Sergei

-- 
   __  ___     ___ ____  __
  /  |/  /_ __/ __/ __ \/ /   Sergei Golubchik <serg@stripped>
 / /|_/ / // /\ \/ /_/ / /__  Principal Software Engineer/Server Architect
/_/  /_/\_, /___/\___\_\___/  Sun Microsystems GmbH, HRB München 161028
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