On Thu, 6 May 2010, Andrew Duane wrote:
It is also useful to make sure that the garbage itself is different. As mentioned before, a single bit error in an otherwise valid value, or maybe a missing/scrambled byte, these are good indications of memory problems. If random places are often overwritten with something else, that could just be another piece of misbehaving code that is writing someplace it shouldn't. I've often found code that writes some buffer into e.g. a piece of memory it no longer owns that looks like memory corruption until you realize the garbage is always something specific like a vnode structure.
There are trickier things too. I once had a machine with bad cache memory where once in a while you would get a cache line that had come from somewhere else in memory. This was particularly vexing when it happened to an I/O buffer, and I wound up with a large zip file that had 32 bytes of libc.so somewhere in the middle... :-(
And of course, swapping out the RAM wouldn't have fixed it. -- Nate Eldredge n...@thatsmathematics.com _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
