From: Date: July 4 2008 8:41am
Subject: Re: mutex contention for the query cache
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Brian Aker wrote:
> Hi!
> 
> On Jul 3, 2008, at 2:05 PM, Sergei Golubchik wrote:
> 
>> extent query cache so that Maria would use exact visibility rules and
>> maximize cache using - all transactions that could see the entry would
>> see it, those that couldn't - wouldn't.
> 
> Well I will look forward to seeing how you solve that for Maria.
> 
>> 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.

/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