Hi there, Recently, I run a little testcase about using mmap to check some physical address.What I found was that the different task can read and write the same physical address at the same time.
For example, I make proc1 to access 0x20000000, read and write "512" to that address every 2 seconds. Meanwhile,I make proc2 to access 0x200000000, read and write "1024" to that address every 1 seconds. The output is a mess, though it needs not be worry on this case, but what about the proc1 and proc2 are both driver, and they mmap to the same physical address? As there are many drivers using /dev/mem and we can not make sure that the different task will not trample on each others memory.Shall we add some printk to help locating the problem when error happened? Thanks, Hu Keping -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
