Re: [Maria-developers] MDEV-5755 - Scalability: let LOCK_open and THR_LOCK::mutex be normal mutexes

3 Mar 2014


      Hi Sergei,

On Sat, Mar 01, 2014 at 07:47:07PM +0100, Sergei Golubchik wrote:
...
Hi, Sergey!
On Feb 27, Sergey Vojtovich wrote:
...
At lp:maria/10.0
------------------------------------------------------------
revno: 4011
revision-id: svoj@mariadb.org-20140227141521-fgj5b0h3qbijyojh
parent: svoj@mariadb.org-20140220072533-l3au3y7mrsyclfpb
committer: Sergey Vojtovich 
branch nick: 10.0
timestamp: Thu 2014-02-27 18:15:21 +0400
message:
  MDEV-5755 - Scalability: let LOCK_open and THR_LOCK::mutex be normal mutexes
Normal mutexes scale better than adaptive at high thread count.
  At low thread count they behave similarly.
To summarize Axel results:
 at low concurency normal can be ~1% slower.
 at high concurrency r/o - normal are up to 25% faster.
 at high concurrency r/w - normal are up to 10% slower.
That last result bothers me a litte.
Indeed. I'll check with Axel about it. Thanks for pointing it out!
Thanks,
Sergey