[Disksim-users] some questions about using disksim4.0

[代成俊]

Thanks for your reply and wonderful explanation.

> > 1,What should I do to get the response time and hitting situation of per request?
> I obtained the response time by modifying the source code. When a
> request is serviced, disk_acctimestats() is called. I got the response
> time by subtracting the current timestamp (i.e. disksim->simtime) by
> the arrival time of the request. You may need to modify Disksim to
> carry the arrival time from the I/O driver down to the disk
> 
> "hitting situation"? Do you mean the cache hit/miss?

I have tried it as your said steps, but failed. disk_acctimestats() is only 
called 88733 times(100000 Requests total), and it only have access time,
where could I get the current timestamp? what does the meaning of "You 
may need to modify Disksim to carry the arrival time from the I/O 
driver down to the disk"? The arrival time should be the time arrival disk?

Overall I/O System Total Requests handled:    99997
Overall I/O System Requests per second:       65.231783
Overall I/O System Completely idle time:      534035.035583       0.348371
Overall I/O System Response time average:     33.897219
Overall I/O System Response time std.dev.:    34.852530
Overall I/O System Response time maximum:    335.193345

This is part of output result of my experiment,In my opinion, the 
"Response time" here shoud be a time range from request arriving 
subsystem to Service completion, is is right? How can I get this 
response time for per request?

Could you sent me a copy of the disksim version(or source files) 
which had been modified exactly to output the respnse time 
for per request? Thank you very much.

Yes, I mean cache hit/miss.


> > 3,The ascii.trace in the valid folder has 100000 requests, but when I run disksim ascii.parv stdout ascii ascii.trace 0,
> > there was only 99993 requests were handled(I have modified the system topology and iomap),Why lost seven request?
> as I remember from Disksim 3.0, when the trace runs out,
> disksim->stop_sim is set to TRUE to stop the simulation, which is
> before all requests are serviced. I believe that's the reason.

I see, but what was the reason for the trace runs out? How can I avoid
this?

Best wishs.

ChengJun Dai.
2012-3-4


> 
> On Sat, Mar 3, 2012 at 7:43 PM, 代成俊 <dcjy at mail.ustc.edu.cn> wrote:
> >
> > Dear Sir(Miss):
> >     I am using disksim(V4.0). My work is to use disksim to simulate one disk(SEAGATE_ST32171W) subsystem.
> > The system topology is just like this:
> >
> > # system topology
> > topology disksim_iodriver driver0 [
> >   disksim_bus bus0 [
> >      disksim_ctlr ctlr0 [
> >         disksim_bus bus1 [
> >            disksim_disk disk0 []
> >         ] # end of bus1
> >      ] # end of ctlr0
> >   ] # end of bus0
> > ] # end of system topology
> >
> > My input is a a series of requests(Request arrival time,Device number,Block number,Request size,Request flags)
> > in a ascii file. The output I want to get is the response time per request and the situation of per request
> > hit cache, but the disksim only output the statistic information of all requests. so I want to consult some questions
> >
> > 1,What should I do to get the response time and hitting situation of per request?
> >
> > 2,The default input format is a simple ASCII stream (or file),which is the unit of "Request arrival time" and
> > "Request size",Seconds milliseconds or microseconds? KB or block?
> >
> > 3,The ascii.trace in the valid folder has 100000 requests, but when I run disksim ascii.parv stdout ascii ascii.trace 0,
> > there was only 99993 requests were handled(I have modified the system topology and iomap),Why lost seven request?
> >
> > Sorry for the my poor english,thank you.
> >
> > Best wishs.
> >
> > ChengJun Dai.
> > 2012-3-4
> > _______________________________________________
> > Disksim-users mailing list
> > Disksim-users at ece.cmu.edu
> > https://sos.ece.cmu.edu/mailman/listinfo/disksim-users
> >
> 
> 
> 
> -- 
> ********************************************
> Yipkei Kwok
> Ph.D. Student
> Research Assistant
> HiPerSys Lab
> Department of Computer Science
> The University of Texas at El Paso
> Phone: 915 747 6433 (O)
> E-mail: ykwok2 at miners dot utep dot edu
> ********************************************
>