Checkpointing vkernels

Thomas E. Spanjaard tgen at
Thu Feb 15 10:10:31 PST 2007

Oliver Fromme wrote:
Matthew Dillon wrote:
 >    You can't at the moment, but only for two simple reasons:  First,
 >    the checkpointing code doesn't save and restore state for
 >    MAP_VPAGETABLE, and second, the vkernel needs a signal handler for
 >    the checkpoint restore to re-create the VM spaces for all of its
 >    virtualized user processes.
 >    Neither of these is difficult to do.  Saving the state for a 
 >    file-backed MAP_VPAGETABLE only requires saving the page table
 >    directory offset and mapping type.  And writing a signal handler
 >    to re-create the VM spaces for all the virtualized user processes
 >    is just as easy, because the VM spaces are all mapped as VPAGETABLE's
 >    on the same physical memory backing file and the vkernel already knows 
 >    the page directory offset for each one.
Cool, I didn't think that it would be relatively easy to
implement that.
Do I hear a volunteer? ;)

        Thomas E. Spanjaard
        tgen at
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