Hi Jason, I want to clarify what I want to do; I want to run a program on gem5 (in SE mode) for 1M instructions and I want to save the memory addresses that every LD instruction loads data from ( I can get those addresses from the pushRequest method in the lsq) http://doxygen.gem5.org/release/current/classLSQ.html and saving those addresses in table (map). After a specific time for example (every100k instructions), I want to access the memory to read the data from those addresses. For instance, let us assume that the address that load instruction loads data from it is (0x7ffff8226e68), can I read the content of this memory address? If so, how?
Thanks gem5: Out of order CPU model<https://www.gem5.org/documentation/general_docs/cpu_models/O3CPU> Memory Order Misspeculation. The InstructionQueue has a MemDepUnit to track memory order dependence. The IQ will not schedule an instruction if MemDepUnit states there is dependency. In LSQUnit::read(), the LSQ will search for possible aliasing store and forward if possible.Otherwise, the load is blocked and rescheduled for when the blocking store completes by notifying the MemDepUnit. www.gem5.org Thanks ________________________________ From: Jason Lowe-Power <ja...@lowepower.com> Sent: Tuesday, August 4, 2020 4:41 PM To: ABD ALRHMAN ABO ALKHEEL <abdkeel...@hotmail.com>; gem5 users mailing list <gem5-users@gem5.org> Subject: Re: [gem5-users] Re: Reading from memory in Gem5 Hello, First of all, please reply to the users list, not directly to the person who responded. This allows everyone to see answers and/or chime in and help. Second, the page you linked is out of date. Please use the main gem5 website for all of the up to date documentation (e.g., http://doxygen.gem5.org/release/current/classLSQUnit.html) Third, I still don't fully understand what your goals are. However, you can use the system port (actually, I think I was wrong before, you should use the "getPort" function, not "getSystemPort") to make functional (or debug) accesses to the memory. You can create a `Packet` with a `Request` and send a functional request across the port (i.e., call sendFunctional(pkt)). You can use either virtual (in SE mode) or physical address (in both modes). I am sure there are some caveats to using virtual addresses, but I don't know exactly what they are. If you're trying to make new timing accesses, then you should use the main "dcache_port" and "icache_port" that are connected to the CPU. Again, you can construct a Packet object with a Request and send it across the port (e.g., sendTimingReq(pkt)). You may want to read up on the details of how gem5's memory objects work: http://www.gem5.org/documentation/learning_gem5/part2/memoryobject/ Cheers, Jason On Mon, Aug 3, 2020 at 1:15 PM ABD ALRHMAN ABO ALKHEEL <abdkeel...@hotmail.com<mailto:abdkeel...@hotmail.com>> wrote: Hi Jason, Thanks for your email. What I want to do is finding the memory address that the LD instruction loads data from ( I can get the physical and virtual address from the Read method in the lsqunit)http://pages.cs.wisc.edu/~swilson/gem5-docs/classLSQUnit.html and saving those addresses. After a specific time, I want to access the memory to read the data from those addresses. Can I use getSystemPort function to access the memory and read the data from those addresses? If so, should I use the virtual address or the physical address? Thanks ________________________________ From: Jason Lowe-Power <ja...@lowepower.com<mailto:ja...@lowepower.com>> Sent: Monday, August 3, 2020 3:26 PM To: gem5 users mailing list <gem5-users@gem5.org<mailto:gem5-users@gem5.org>> Cc: gem5-users <gem5-users-boun...@gem5.org<mailto:gem5-users-boun...@gem5.org>>; ABD ALRHMAN ABO ALKHEEL <abdkeel...@hotmail.com<mailto:abdkeel...@hotmail.com>> Subject: Re: [gem5-users] Re: Reading from memory in Gem5 Hello, This sounds like you probably want to use "functional" accesses. These are built for introspection and debugging, which is what it sounds like you want to do. Using the System object, there is a `getSystemPort` function that will return a gem5 port that you can use with functional accesses to "backdoor" into the memory. See http://doxygen.gem5.org/release/current/classSystem.html#a5ecbd1eaa3e0d19f4640bb71a0b59d64. Cheers, Jason On Sun, Aug 2, 2020 at 7:01 AM ABD ALRHMAN ABO ALKHEEL via gem5-users <gem5-users@gem5.org<mailto:gem5-users@gem5.org>> wrote: Hi All, how to read data from memory in Gem5 ? Can I read data from memory in Gem5 for a specific addresses? If so, should I use the virtual address or physical address? For example, how load instructions read the data from memory? Any help would be appreciated. Thanks ________________________________ From: ABD ALRHMAN ABO ALKHEEL Sent: Saturday, August 1, 2020 3:19 PM To: gem5 users mailing list <gem5-users@gem5.org<mailto:gem5-users@gem5.org>>; gem5-users <gem5-users-boun...@gem5.org<mailto:gem5-users-boun...@gem5.org>> Subject: Reading from memory in Gem5 Hi All, how to read data from memory in Gem5 ? Can I read data from memory in Gem5 for a specific addresses? If so, should I use the virtual address or physical address? For example, how load instructions read the data from memory? Any help would be appreciated. Thanks _______________________________________________ gem5-users mailing list -- gem5-users@gem5.org<mailto:gem5-users@gem5.org> To unsubscribe send an email to gem5-users-le...@gem5.org<mailto:gem5-users-le...@gem5.org> %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s
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