gmirror 'load' algorithm (Was: Re: siis/atacam/ata/gmirror 8.0-BETA3 disk performance)

[Maxim Sobolev]

Alexander Motin wrote:
> ### load mav@
>              linear 1MB read     random
> 1 process       MBps: 104       tps: 159
> 2 processes     MBps: 214       tps: 256
> 4 processes     MBps: 425       tps: 332
> 5 processes     MBps: 300       tps: 352
> 8 processes     MBps: 245       tps: 391
> 16 processes    MBps: 255       tps: 436
> 32 processes    MBps: 263       tps: 457
> 
> Random is close to round-robin. Request balancing is close to perfect.
> Linear shows maximum possible performance for number of processes up to
> the number of drives, using only as much disks as needed. With more
> processes then disks, performance predictably reducing, but still beats
> all other methods.
> 
> I think it is hardly possible to get much more.
> 

Awesome, please commit - this issue has been dragging for too long 
already. Pawel seems either busy or have lost interest in maintaining 
this, so you don't really need to wait for his approval.

-Maxim