Re: pagebuf_prepare_write doesn't kmap the page

[Jens Axboe <axboe@xxxxxxx>]

On Wed, Jan 31 2001, Steve Lord wrote:
> One noticable change in dbench is that in 2.4.0 - and for a long time
> prior to that, the individual dbench programs used to complete at widely
> differing times, now they pretty much all get a fair share of the system
> and we end up with them all running for about the same time. I suppose this
> would mean more memory load on the system for the whole duration of the run,
> where before the longer running threads got to run under lighter load once
> the other threads had finished.
> 
> This would probably account for the slowdown.

This is exactly the reason as I outlined -- letting them complete
without paying too much attention to latencies of individual dbench
threads gives you much better results.

dbench is a good benchmark, you just have to keep in mind what it
measures and not just eat the numbers up raw ;-)

-- 
Jens Axboe