Re: IO scheduler based IO controller V10

[Mike Galbraith <efault@gmx.de>]

On Fri, 2009-10-02 at 20:57 +0200, Mike Galbraith wrote:
> On Fri, 2009-10-02 at 20:19 +0200, Jens Axboe wrote:
> 
> > I'm not too worried about the "single IO producer" scenarios, and it
> > looks like (from a quick look) that most of your numbers are within some
> > expected noise levels. It's the more complex mixes that are likely to
> > cause a bit of a stink, but lets worry about that later. One quick thing
> > would be to read eg 2 or more files sequentially from disk and see how
> > that performs.
> 
> Hm.  git(s) should be good for a nice repeatable load.  Suggestions?
> 
> > If you could do a cleaned up version of your overload patch based on
> > this:
> > 
> > http://git.kernel.dk/?p=linux-2.6-block.git;a=commit;h=1d2235152dc745c6d94bedb550fea84cffdbf768
> > 
> > then lets take it from there.
> 
> I'll try to find a good repeatable git beater first.  At this point, I
> only know it helps with one load.

Seems to help mixed concurrent read/write a bit too.

perf stat testo.sh                               Avg
108.12   106.33    106.34    97.00    106.52   104.8  1.000 fairness=0 overload_delay=0
 93.98   102.44     94.47    97.70     98.90    97.4   .929 fairness=0 overload_delay=1
 90.87    95.40     95.79    93.09     94.25    93.8   .895 fairness=1 overload_delay=0
 89.93    90.57     89.13    93.43     93.72    91.3   .871 fairness=1 overload_delay=1

#!/bin/sh

LOGFILE=testo.log
rm -f $LOGFILE

echo 3 > /proc/sys/vm/drop_caches
sh -c "(cd linux-2.6.23; perf stat -- git checkout -f; git archive --format=tar HEAD > ../linux-2.6.23.tar)" 2>&1|tee -a $LOGFILE &
sh -c "(cd linux-2.6.24; perf stat -- git archive --format=tar HEAD > ../linux-2.6.24.tar; git checkout -f)" 2>&1|tee -a $LOGFILE &
sh -c "(cd linux-2.6.25; perf stat -- git checkout -f; git archive --format=tar HEAD > ../linux-2.6.25.tar)" 2>&1|tee -a $LOGFILE &
sh -c "(cd linux-2.6.26; perf stat -- git archive --format=tar HEAD > ../linux-2.6.26.tar; git checkout -f)" 2>&1|tee -a $LOGFILE &
wait