On 24 April 2015 at 08:01, Mark Williamson <mwilliamson@xxxxxxxxxxxxxxxxx> wrote: > In our use of /proc/PID/pagemap, we currently make use of the physical > pageframe addresses. We should be able to work with a scrambled > representation of these (Andy Lutomirski suggested this in the > original discussion - https://lkml.org/lkml/2015/3/16/1273) so long as > the scrambling remained consistent during the lifetime of the open > pagemap file. Alternatively, if physical addresses were simply zeroed > (also suggested by Pavel Emelyanov - > https://lkml.org/lkml/2015/3/9/871) we would be able to change our > code to rely only on the soft-dirty flag and thus still work > correctly. I'm curious, what do you use the physical page addresses for? Since you pointed to http://undo-software.com, which talks about reversible debugging tools, I can guess you would use the soft-dirty flag to implement copy-on-write snapshotting. I'm guessing you might use physical page addresses for determining when the same page is mapped twice (in the same process or different processes)? Cheers, Mark -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
