Re: Random file I/O regressions in 2.6

[Ram Pai <linuxram@us.ibm.com>]

On Tue, 2004-05-04 at 12:58, Ram Pai wrote:
> On Tue, 2004-05-04 at 12:48, Andrew Morton wrote:
> > Ram Pai <linuxram@us.ibm.com> wrote:
> > >
> > > I ran the following command:
> > > 
> > >  /root/sysbench-0.2.5/sysbench/sysbench --num-threads=256 --test=fileio
> > >  --file-total-size=2800M --file-test-mode=rndrw run 
> > > 
> > 
> > Alexey and I have been using 16 threads.
> >
 /root/sysbench-0.2.5/sysbench/sysbench --num-threads=16 --test=fileio
--file-total-size=2800M --file-test-mode=rndrw run 

Without the patch:
------------------

Operations performed:  6002 Read, 3998 Write, 12800 Other = 22800 Total
Read 93Mb  Written 62Mb  Total Transferred 156Mb
   1.967Mb/sec  Transferred
  126.11 Requests/sec executed

Test execution Statistics summary:
Time spent for test:  79.2986s

no of times window reset because of hits: 0
no of times window reset because of misses: 119
no of times window was shrunk because of hits: 417
no of times the page request was non-contiguous: 3809
no of times the page request was contiguous : 12745

With the patch:
--------------
Operations performed:  6002 Read, 3999 Write, 12672 Other = 22673 Total
Read 93Mb  Written 62Mb  Total Transferred 156Mb
   2.927Mb/sec  Transferred
  187.65 Requests/sec executed

Test execution Statistics summary:
Time spent for test:  53.2949s

no of times window reset because of hits: 0
no of times window reset because of misses: 0
no of times window was shrunk because of hits: 360
no of times the page request was non-contiguous: 5860
no of times the page request was contiguous : 20378


Impressive results. WOuld be nice to get a confirmation from Alexey.
RP