Yep that is the beauty of the random tester.  It is much easier to fix problems 
when you can reproduce them in 3 M cycles vs. 200 B.

Brad


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of 
Nilay
Sent: Tuesday, December 21, 2010 8:00 PM
To: M5 Developer List
Subject: Re: [m5-dev] Deadlock while running ruby_random_test.py

It is kind of surprising that random tester can detect the bug with in
3,000,000 cycles while nothing happened on running ruby_fs.py for
200,000,000,000 cycles.


On Tue, December 21, 2010 8:24 pm, Nilay Vaish wrote:
> Brad, which protocols work correctly with ruby random tester?
>
> On Tue, 21 Dec 2010, Beckmann, Brad wrote:
>
>> Hi Nilay,
>>
>> If I'm correctly reproducing your problem, I believe I know what the 
>> issue is.  However, before I try to fix it, I want to propose simply 
>> getting rid of the MESI_CMP_directory.  The more and more I look at 
>> that protocol, the more problems I see.  There are several design and 
>> logic issues in the protocol.  Unless someone wants to volunteer to 
>> fix them, I say we get rid of it as well as all of the protocols not 
>> being tested by the regression tester.
>>
>> Now the particular problem that I see causing the deadlock is that 
>> that
>> L2 cache is drop a PUTX request from the L1 because the L2 is in 
>> SS_MB state.  Thus the L1 remains in M_I state for infinity which of 
>> course will eventually lead to a deadlock.
>>
>> Brad
>>
>>
>> -----Original Message-----
>> From: [email protected] [mailto:[email protected]] On 
>> Behalf Of Nilay Vaish
>> Sent: Tuesday, December 21, 2010 1:04 PM
>> To: [email protected]
>> Subject: [m5-dev] Deadlock while running ruby_random_test.py
>>
>> I am running ALPHA_SE_MESI_CMP_directory with ruby_random_test.py. I 
>> supply the option -l as 2000. I have pasted the output below. This 
>> was generated using latest version of m5.
>>
>> Actually, while testing my own changes to SLICC and protocol files, I 
>> also observe the dead lock at the 3000001. So I ran the latest 
>> version and found even that gets stuck.
>>
>> Is this a known problem? Am I doing some thing wrong?
>>
>> Thanks
>> Nilay
>>
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--
Nilay

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