Messages in this thread | | | Date | Fri, 2 Oct 2009 11:24:09 +0200 | From | Ingo Molnar <> | Subject | Re: IO scheduler based IO controller V10 |
| |
* Jens Axboe <jens.axboe@oracle.com> wrote:
> It's not hard to make the latency good, the hard bit is making sure we > also perform well for all other scenarios.
Looking at the numbers from Mike:
| dd competing against perf stat -- konsole -e exec timings, 5 back to | back runs | Avg | before 9.15 14.51 9.39 15.06 9.90 11.6 | after [+patch] 1.76 1.54 1.93 1.88 1.56 1.7
_PLEASE_ make read latencies this good - the numbers are _vastly_ better. We'll worry about the 'other' things _after_ we've reached good latencies.
I thought this principle was a well established basic rule of Linux IO scheduling. Why do we have to have a 'latency vs. bandwidth' discussion again and again? I thought latency won hands down.
Ingo
| |