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Hello everybody,
I need to count reads and writes to the memory allocated by mmap().
I tried Valgrind, but it counts only the heap accesses and mmap() doesn't allocate in the heap !!
Please, could someone help me to achieve my purpose (counting reads and writes in mmap()'d area)?
Thank you
I searched online for variations of the term mmap monitoring and did not find anything that appeared to directly answer your question. I see no obvious facility for monitoring accesses to mmaped memory as you describe.
probably impossible, because you can pass mmapped address to external functions (libc ...) and also mmapped memory can be accessed from several processes.
I would try to create some wrapper functions to be able to log access.
I don't think it would be possible without a specific CPU instruction, say START/STOP_VIRTUAL_MEMORY_USAGE_STATISTICS MINADDR=addr MAXADDR=addr INTO=addr
What's the real problem ?. Simple things can be strace'd - libc:read and write can be dynamically probed. The kernel functions likewise. Not many would describe that as "simple", although it is getting easier.
Hello everybody,
I need to count reads and writes to the memory allocated by mmap().
I tried Valgrind, but it counts only the heap accesses and mmap() doesn't allocate in the heap !!
Please, could someone help me to achieve my purpose (counting reads and writes in mmap()'d area)?
Thank you
Resolved.
I have used this command line:
valgrind --tool=lackey --trace-mem=yes --log-file=outputlackey.txt <command>
This will trace all the memory space of the process <command> that has been monitored and logs a file.
First of all, I got the address returned by mmap() function. Then, I read the log file, and I counted the number of the Loads and Stores. You can look at the details of the output. https://github.com/mozilla-b2g/valgr...ckey/lk_main.c
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