← Back to team overview

maria-developers team mailing list archive

Re: bzr commit into MariaDB 5.1, with Maria 1.5:maria branch (monty:2680)



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

Sergei> Hi, Michael!
Sergei> On Mar 18, Michael Widenius wrote:
>> >>>>> "Sergei" == Sergei Golubchik <sergii@xxxxxxxxx> writes:
Sergei> Hi, Michael!
Sergei> On Mar 12, Michael Widenius wrote:
>> >> #At lp:maria based on revid:monty@xxxxxxxxxxxx-20090309141344-wriztb0fcn00syim
>> >> 
>> >> 2680 Michael Widenius	2009-03-13
>> >> Added "pool-of-threads" handling (with libevent)
>> >> This is a backport of code from MySQL 6.0 with cleanups and extensions
>> >> 
>> >> The following new options are supported
>> >> configure options:
>> >> --with-libevent ; Enable use of libevent, which is needed for pool of threads
Sergei> Are you aware of the current scalability problems with the pool of
Sergei> threads in 6.0 ? What are you going to do about it ?
>> No, haven't followed this discussion. Will look for it.

Sergei> Just found something relevant: http://bugs.mysql.com/42288
Thanks; Read this with a great deal of interest and was looking at the
code involving LOCK_event_loop mutex to understand the problem.

It's totally understandable why this happens; All waiting is now done
on this mutex, as only one thread can be inside the event_loop() at
the same time.

The original code for Solaris didn't have any mutex that was hold for
more than a couple of instructions, which should make it notable faster.

Need to study the event_loop() code to know how tread safe this part
of the code is.


Follow ups