MyISAM Keycache Scalibity Bottleneck

Hi Peter, Hello Everybody,

Peter in one of your post you mentioned that the mutex which is used/needed for access the MyISAM Key-Cache is a scalibity limitation.

I believe you mentioned that the mutex is hold for the time needed to copy the key-cache block from/to the thread space.
Do I remember this right?

Wouldn’t this mean, if we could accelerate the function which copies the key-block, then we will improve MyISAM scalibity?

Do you know by chance which MySQL function is used for copying the key-block?
I would guess “bmove512” is this correct?

If this is true then it might be real easy to improve this.
As accelerating this function is not difficult at all.


Gunnar, I’m not that familiar with this source code myself. I’ll ask Peter to reply to you.