Re: [Maria-developers] benchmarking next steps

This is good news. Don't forget to have someone write a blog post about it. On Tue, Jan 21, 2014 at 7:04 AM, Michael Widenius wrote:

Hi!

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"Sergey" == Sergey Vojtovich writes:

Sergey> Hi Mark, Sergey> we identified a few single-thread performance issues during the Barcelona Sergey> meeting. Monty should have them fixed in his private tree. Fixes are quite Sergey> generic and should improve performance almost in all cases. An exception is Sergey> bottlenecks specific to certain use cases.

A short followup of the above:

While testing trivial queries, we noticed some code paths at top that should not be there: - Mallocs (simple queries should be run without any mallocs). - I managed to remove some of them. - Some atomic increments/sum could be avoided. (For simple SELECT * FROM empty_table, an atomic increment could take almost 1% of execution time) - This was fixed by marking more memory as THREAD_SPECIFIC and not do atomic operations on these until SHOW STATUS - Lots of calls to current_thd - A large portion of these calls are now removed. - Some byte rotate operations where slower than expected. These was often used in Aria tables and MyISAM tables. - We will replace these with one assembler instructions for X64 ships which will make them MUCH faster.

I have done the above fixed in my 10.0 tree. I just need to finalize and benchmark this before I push...

Regards, Monty

-- Mark Callaghan mdcallag@gmail.com