maria-developers team mailing list archive

[Michael Widenius <monty@xxxxxxxxxxxx>]

Hi!

>>>>> "Sergei" == Sergei Golubchik <sergii@xxxxxxxxx> writes:

Sergei> Hi, Monty!
Sergei> On Oct 19, Michael Widenius wrote:
>> 
>> I just finished applying / modifying / rewriting the userstats patch
>> to MariaDB 5.2 and will commit this in a moment.

Sergei> I wonder if anybody cares to monitor mutex usage in MySQL.

Sergei> This patch adds few new global mutexes that are locked at least once per
Sergei> statement (or more).

Sergei> Without benchmark results one can only speculate whether it will affect
Sergei> users or not.

I already asked Hakan to test this.

The good news is that the mutex are only taken if the statistics are
enabled.

The bad news is that there are some global mutex when you gather the
statistics.

My intial work was to implement into MariaDB the latest userstat patch
that was made available/known to me.  At least the one that I
implemented should be notable better to what where available at
percona, ourdelta or made by Weldon.

Now when we have the basic implementation done (very usefull already),
it's time to see what we can fix in the next step.

If any has a patch to fix the issues, we would greatly appreciate it :)

Regards,
Monty