[Disksim-users] 'Make - clean' issue
Francesco Falanga
ffalanga at fastwebnet.it
Sat Apr 2 14:22:49 EDT 2011
Hi Jonathan,
your continuos support is very appreciated.
Would you kindly try to send again Compiling_FlashSim doc again but in pdf format? I never got it before.
I am having some issue while trying to open with word ( some conversion error).
Thank you!
Francesco.
----- Original Message -----
From: Jonathan Tjioe
To: Francesco Falanga
Cc: disksim-users at ece.cmu.edu
Sent: Saturday, April 02, 2011 6:26 PM
Subject: Re: 'Make - clean' issue
Francesco,
I had this same issue whenever I would do a 'make clean'. I am fortunate b/c the only files I really need to modify are dftl.c, fast.c, and pagemap.c. My workaround isn't the most elegant solution, but it works. In the Compiling FlashSim guide that I sent you previously, right before I do step 7 (which is the 'make' step), I create a snapshot of my Ubuntu VM. After the snapshot is complete, I can easily revert back to the snapshot, make any changes to my c code and then run 'make' again. Another way you can do it is to just create a copy of your 'src' directory prior to running a 'make' on it ('cp -p src src.orig'). And whenever you want to modify the code and recompile, you need to just delete the src directory and copy the original one back in place ('rm -r src; cp -p src.orig src').
One of the problems for the 'make clean' is that it deletes the files. When it tries to regenerate them again with the 'make', it puts several of the fprintf statements across multiple lines, which for some reason do not compile in the gcc version that we are running (I'm assuming it is the gcc version that is the culprit...remember, this version of disksim 3.0/flashsim is tightly coupled to gcc 3.3.6). So when I originally got disksim working, I had to manually grep for fprintf in the src directory (`grep fprintf ~/src`) and find all of the files that had fprintf statements that spanned multiple lines and then go modify all of these to be on a single line. I probably had to do this for 15-20 fprintf statements in various files throughout the code. So if you look at my steps in the Compiling Flash Sim guide, I have already modified all of these fprintf statements for you in the attached .gz file. Once you extract this src directory according to the instructions, this is what your src.orig should be based off of.
Again, this isn't the most graceful solution but this worked for me.
Also, please include the disksim users email list in your replies to me so that everyone can benefit from our discussion as I know many others are having the same issues. Thanks!
To the other DiskSim users out there, if anyone knows the webadmin to this page: http://csl.cse.psu.edu/?q=node/322 could you please have them email me? I would like to post my FlashSim instructions and the updated tar file (both attached) on there for others to use so they can easily get FlashSim running.
Thanks!
Jonathan
On Sat, Apr 2, 2011 at 8:25 AM, Francesco Falanga <ffalanga at fastwebnet.it> wrote:
Hi Jonathan,
As I have already mentioned everything is ok when I follow your instruction for getting disksim 3.0 working. But when I issue a 'make clean' to rebuild all the project ( I am trying to debug with code block) then I get some src file modified again so that I get compilation errors.
Can you please help me on this?
Best Regards,
Francesco.
----- Original Message -----
From: Jonathan Tjioe
To: changyue
Cc: disksim-users at ece.cmu.edu
Sent: Thursday, March 24, 2011 2:40 AM
Subject: Re: [Disksim-users] DiskSim 3.0/FlashSim Simulation problems
Can you be more specific? Which parameters in particular do I need to modify?
Basically, the only thing that I did was the following:
1) Divided the request size (bytes) by 512 because my sectors are 512Bytes. So now the size is in sectors. To my understanding, this is what DiskSim requires.
2) I changed the device number to always be 0 (since I am only simulating one SSD)
3) I moved the parameters around from SPC format to disksim format as follows:
<arrival time> <devicenum> <LBA> <size in # of sectors> <1 or 0 for read or write>
Are there other modifications that I need to do besides that?
Thanks,
Jonathan
2011/3/23 changyue <cy_3108079008 at hotmail.com>
Hi,
If you want to use the IO trace file directly that download from the website (for example,Financial 1), you must filter the trace file to fit your disk parameter. It is a hard question that I have tried do it nearly , but not successful.
Thanks!
------------------------------------------------------------------------
Date: Tue, 22 Mar 2011 19:47:59 -0700
From: jontjioe at gmail.com
To: alexander.lochmann at tu-dortmund.de
CC: axg354 at cse.psu.edu; andresblanco_89 at yahoo.com; disksim-users at ece.cmu.edu; youkim at cse.psu.edu
Subject: Re: [Disksim-users] DiskSim 3.0/FlashSim Simulation problems
Alex,
I've moved your responses up to the top so the rest of the forum won't get confused trying to distinguish the your responses from my questions.
I've also CCed Aayush Gupta and Youngjae Kim as they were the authors of the DFTL paper that my environment is based on. Hopefully, they can shed some light on what I'm doing wrong.
On your response to Error #1 (Segmentation fault)...
When I run it for the Financial1 trace file using all 3 FTLs, I get the following output to screen:
Running Pagemap FTL...
start_blk_no: 1107318608, block_cnt: 4, total_util_sect_num: 2097152
Running DFTL...
./runtest: line 11: 5905 Segmentation fault ../src/disksim dftl.parv dftl.outv ascii ./trace/test.file 0
Running FAST...
start_blk_no: 1107318608, block_cnt: 4, total_util_sect_num: 2097152
As stated earlier, if I check the .outv files that were generated for each of these FTLs, none of the simulations ever completed.
I have not run it using gdb. The code is compiled already. I suppose I could try to do so, but I would think that I should be able to run it as is.
I have also attached the exact script that I run when I simulate the 3 FTLs. Again, this is the same exact environment that the DFTL authors used.
On your response to Error #2 (simulation stopped due to saturation), when running runtest script against the Financial2 trace file, I get this output to the screen.
Running Pagemap FTL...
Stopping simulation because of saturation: simtime 108.435867, totalreqs 10394
IOdriver Response time average: 17.003924
IOdriver Response time std.dev.: 15.487314
Running DFTL...
Stopping simulation because of saturation: simtime 107.151359, totalreqs 10255
IOdriver Response time average: 25.488591
IOdriver Response time std.dev.: 19.068197
Running FAST...
Stopping simulation because of saturation: simtime 106.554985, totalreqs 10188
IOdriver Response time average: 10.128997
IOdriver Response time std.dev.: 8.028486
As far as slowing down the request-ratio...well, I could be misunderstanding what you are saying, but I thought that the way it works is that the real world requests come in exactly as the arrival times state in the trace file. Then if the hard drive(s) is(are) busy, then they just go in the request queue waiting to be serviced. I could understand that for a synthetically generated trace, it might be worth slowing down the request ratio just to see what happens, but this is a real world trace. So if I slowed down the request-ratio, this would mean modifying the arrival times, which would invalidate the trace as it would no longer be real world.
Thanks,
Jonathan
On Tue, Mar 22, 2011 at 1:09 AM, Alexander Lochmann <alexander.lochmann at tu-dortmund.de> wrote:
Hi!
On Error #1 (Segmentation fault), could give us some more information?
Have you tried to run it with gdb und typed "bt"?
On Error #2 (Simulation stopped due to saturation), maybe your harddisk model is too slow to serve the requests within a appropriate amount of time so the requestqueue doesn't get saturated. In a real system you've got a operating system which keeps track of this issue. Linux for example, slows down every readahead and writeback activity to reduce the number of requests if it detects congestion conditions. It has a requestqueue which is on top of the driver holding every request.
Have you tried to slow down the request-ratio?
Greetings
Alex
Am 22.03.2011 03:05, schrieb Jonathan Tjioe:
DiskSim users,
First, let me apologize for making this email so long. I wanted it to be thorough so my problem is explained clearly.
I'm running DiskSim 3.0 with FlashSim (same as the FlashSim in the DFTL paper). It's basically DiskSim 3.0 with support for SSD.
I've been running the "runtest" script which basically runs a small sample test file through all 3 FTLs: Page mapped, DFTL, and FAST. The test trace that was included is very small (8-9MB) and I get the intended results as the authors of the DFTL paper did.
All the runtest script does is run the same trace file on these 3 FTLs:
../src/disksim pagemap.parv pagemap.outv ascii ./trace/test.file 0
../src/disksim dftl.parv dftl.outv ascii ./trace/test.file 0
../src/disksim fast.parv fast.outv ascii ./trace/test.file 0
Upon successful completion of the simulation, I noticed that in the .outv files, I will see:
<<
...
loadparams complete
Initialization complete
Simulation complete
...
>>
After this, I will see many performance statistics along with every request. I get the appropriate results when simulating DFTL, FAST, and pure page mapped FTL.
However, once I tried putting any other real world trace (which is much longer) in the simulation, it does not complete successfully. It should be noted that I have not made any modifications to any of the 3 FTLs during these tests. I have verified that my format of the trace files is correct:
<arrival time> <devicenum> <LBA> <size in # of sectors> <1 or 0 for read or write>
There are 3 different results that I get, all of which are unsuccessful simulations:
1) Segmentation fault
2) Simulation is stopped because of saturation
3) Simulation seems like it finished, but when you check the .outv files, the last line says "initialization complete" (in otherwords it does not ever say "simulation complete"
One example (Error #1) is when I run the entire finanical trace in, I get a segmentation fault simulating DFTL. Although I didn't get segmentation faults for FAST or pure page mapped, their corresponding .outv files do not look correct. They seem like they never finished simulating. In the .outv files for all 3 FTLs, it shows:
<<
...
loadparams complete
Initialization complete
>>
But it never shows "simulation complete" and thus the results are not shown in the .outv file. The weird thing is that if I just include maybe several hundred lines of the Financial1 trace instead of the entire thing, it completes successfully with no problem, so I know my format of the file is correct.
Another example (Error #2) I noticed that I the Financial2 trace did not have any segmentation faults but instead I had a different message:
<<
Stopping simulation because of saturation: simtime 108.435867, totalreqs 10394
>>
I did some research and found that there is a define statement in disksim_logorg.c that sets the MAX_QUEUE_LENGTH to be 10000. In each of the instances when the simulation stopped due to saturation, the totalreqs number was just over 10000. I imagine the queue length is getting very large due to the fact that I only have a device num of 0 since my GC algorithm will be a local GC algorithm, not a inter-disk algorithm.
And lastly, if (Error #1) or (Error #2) occur, the simulation will never complete and no simulation summary will be in the .outv file (which is Error #3).
My questions are as follows:
Regarding (Error #1), I have no idea why I am getting segmentation faults. Do you think it is some type of buffer overflow issue b/c there is so much data with the real world traces? Remember, that if I just take a smaller subset of the real world data, it simulates to completion without any problem.
Regarding (Error #2), I can try just increasing the MAX_QUEUE_LENGTH to maybe 100000 and see what happens, but is that the right solution or is there something else that I need to be aware of.
Regarding (Error #3), I would assume that this will be solved once I find the solutions to (Error #1) and (Error #2).
I really appreciate any help or hints you can offer. I will also post this to the disksims mailing list.
Thanks for your valuable time,
Jonathan Tjioe
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