If you can, it's best to just use code other people have already
written :)
If you can reboot the computer to test the memory, Memtest86+ is a
well-known and very reliable tool which does just what you ask. You can
obtain it from http://www.memtest.org/
There's some work done on an in-kernel memory tester, but testing memory
while Linux is running is somewhat limited as there are sections of
memory that you can't overwrite during testing. Take a look at
CONFIG_MEMTEST and arch/x86/mm/memtest.c (which is currently only
capable of testing memory in early boot).
--
Calvin Walton <calvin.walton@gmail.com>
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